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Lismer A, Shao X, Dumargne MC, Lafleur C, Lambrot R, Chan D, Toft G, Bonde JP, MacFarlane AJ, Bornman R, Aneck-Hahn N, Patrick S, Bailey JM, de Jager C, Dumeaux V, Trasler JM, Kimmins S. The Association between Long-Term DDT or DDE Exposures and an Altered Sperm Epigenome-a Cross-Sectional Study of Greenlandic Inuit and South African VhaVenda Men. Environ Health Perspect 2024; 132:17008. [PMID: 38294233 PMCID: PMC10829569 DOI: 10.1289/ehp12013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/26/2023] [Accepted: 12/20/2023] [Indexed: 02/01/2024]
Abstract
BACKGROUND The organochlorine dichlorodiphenyltrichloroethane (DDT) is banned worldwide owing to its negative health effects. It is exceptionally used as an insecticide for malaria control. Exposure occurs in regions where DDT is applied, as well as in the Arctic, where its endocrine disrupting metabolite, p , p ' -dichlorodiphenyldichloroethylene (p , p ' -DDE) accumulates in marine mammals and fish. DDT and p , p ' -DDE exposures are linked to birth defects, infertility, cancer, and neurodevelopmental delays. Of particular concern is the potential of DDT use to impact the health of generations to come via the heritable sperm epigenome. OBJECTIVES The objective of this study was to assess the sperm epigenome in relation to p , p ' -DDE serum levels between geographically diverse populations. METHODS In the Limpopo Province of South Africa, we recruited 247 VhaVenda South African men and selected 50 paired blood serum and semen samples, and 47 Greenlandic Inuit blood and semen paired samples were selected from a total of 193 samples from the biobank of the INUENDO cohort, an EU Fifth Framework Programme Research and Development project. Sample selection was based on obtaining a range of p , p ' -DDE serum levels (mean = 870.734 ± 134.030 ng / mL ). We assessed the sperm epigenome in relation to serum p , p ' -DDE levels using MethylC-Capture-sequencing (MCC-seq) and chromatin immunoprecipitation followed by sequencing (ChIP-seq). We identified genomic regions with altered DNA methylation (DNAme) and differential enrichment of histone H3 lysine 4 trimethylation (H3K4me3) in sperm. RESULTS Differences in DNAme and H3K4me3 enrichment were identified at transposable elements and regulatory regions involved in fertility, disease, development, and neurofunction. A subset of regions with sperm DNAme and H3K4me3 that differed between exposure groups was predicted to persist in the preimplantation embryo and to be associated with embryonic gene expression. DISCUSSION These findings suggest that DDT and p , p ' -DDE exposure impacts the sperm epigenome in a dose-response-like manner and may negatively impact the health of future generations through epigenetic mechanisms. Confounding factors, such as other environmental exposures, genetic diversity, and selection bias, cannot be ruled out. https://doi.org/10.1289/EHP12013.
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Affiliation(s)
- Ariane Lismer
- Department of Pharmacology and Therapeutics, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada
| | - Xiaojian Shao
- Digital Technologies Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Marie-Charlotte Dumargne
- Department of Animal Science, Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, Quebec, Canada
| | - Christine Lafleur
- University of Montreal Hospital Research Centre, Montreal, Quebec, Canada
| | - Romain Lambrot
- University of Montreal Hospital Research Centre, Montreal, Quebec, Canada
| | - Donovan Chan
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Gunnar Toft
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Jens Peter Bonde
- Department of Occupational and Environmental Medicine, Bispebjerg University Hospital, Copenhagen, Denmark
- Institute of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Amanda J. MacFarlane
- Agriculture Food and Nutrition Evidence Center, Texas A&M University, Fort Worth, Texas, USA
| | - Riana Bornman
- Environmental Chemical Pollution and Health Research Unit, School of Health Systems and Public Health, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- University of Pretoria Institute for Sustainable Malaria Control, School of Health Systems and Public Health, Faculty of Health Sciences, University of Pretoria, South Africa
| | - Natalie Aneck-Hahn
- University of Pretoria Institute for Sustainable Malaria Control, School of Health Systems and Public Health, Faculty of Health Sciences, University of Pretoria, South Africa
| | - Sean Patrick
- University of Pretoria Institute for Sustainable Malaria Control, School of Health Systems and Public Health, Faculty of Health Sciences, University of Pretoria, South Africa
| | - Janice M. Bailey
- Research Centre on Reproduction and Intergenerational Health, Department of Animal Sciences, Université Laval, Quebec, Quebec, Canada
| | - Christiaan de Jager
- Environmental Chemical Pollution and Health Research Unit, School of Health Systems and Public Health, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- University of Pretoria Institute for Sustainable Malaria Control, School of Health Systems and Public Health, Faculty of Health Sciences, University of Pretoria, South Africa
| | - Vanessa Dumeaux
- Department of Anatomy and Cell Biology, Western University, London, Ontario, Canada
- Department of Oncology, Western University, London, Ontario, Canada
| | - Jacquetta M. Trasler
- Department of Pharmacology and Therapeutics, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
- Department of Human Genetics, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
- Department of Pediatrics, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Sarah Kimmins
- Department of Pharmacology and Therapeutics, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada
- University of Montreal Hospital Research Centre, Montreal, Quebec, Canada
- Department of Pathology and Cell Biology, Faculty of Medicine, University of Montreal, Quebec, Canada
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Chan D, Ly L, Rebolledo EMD, Martel J, Landry M, Scott-Boyer MP, Droit A, Trasler JM. Transgenerational impact of grand-paternal lifetime exposures to both folic acid deficiency and supplementation on genome-wide DNA methylation in male germ cells. Andrology 2023. [PMID: 36697378 DOI: 10.1111/andr.13399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 01/05/2023] [Accepted: 01/22/2023] [Indexed: 01/27/2023]
Abstract
BACKGROUND DNA methylation (DNAme) erasure and reacquisition occur during prenatal male germ cell development; some further remodeling takes place after birth during spermatogenesis. Environmental insults during germline epigenetic reprogramming may affect DNAme, presenting a potential mechanism for transmission of environmental exposures across multiple generations. OBJECTIVES We investigated how germ cell DNAme is impacted by lifetime exposures to diets containing either low or high, clinically relevant, levels of the methyl donor folic acid and whether resulting DNAme alterations were inherited in germ cells of male offspring of subsequent generations. MATERIALS AND METHODS Female mice were placed on a control (FCD), 7-fold folic acid deficient (7FD) or 10- to 20-fold supplemented (10FS and 20FS) diet before and during pregnancy. Resulting F1 litters were weaned on the respective diets. F2 and F3 males received control diets. Genome-wide DNAme at cytosines (within CpG sites) was assessed in F1 spermatogonia, and in F1, F2 and F3 sperm. RESULTS In F1 germ cells, a greater number of differentially methylated cytosines (DMCs) were observed in spermatogonia as compared with F1 sperm for all folic acid diets. DMCs were lower in number in F2 versus F1 sperm, while an unexpected increase was found in F3 sperm. DMCs were predominantly hypomethylated, with genes in neurodevelopmental pathways commonly affected in F1, F2 and F3 male germ cells. While no DMCs were found to be significantly inherited inter- or transgenerationally, we observed over-representation of repetitive elements, particularly young long interspersed nuclear elements (LINEs). DISCUSSION AND CONCLUSION These results suggest that the prenatal window is the time most susceptible to folate-induced alterations in sperm DNAme in male germ cells. Altered methylation of specific sites in F1 germ cells was not present in later generations. However, the presence of DNAme perturbations in the sperm of males of the F2 and F3 generations suggests that epigenetic inheritance mechanisms other than DNAme may have been impacted by the folate diet exposure of F1 germ cells.
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Affiliation(s)
- Donovan Chan
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Lundi Ly
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Edgar Martínez Duncker Rebolledo
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Josée Martel
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Mylène Landry
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | | | - Arnaud Droit
- Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
| | - Jacquetta M Trasler
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Department of Human Genetics, McGill University, Montreal, QC, Canada.,Departments of Pediatrics and Pharmacology & Therapeutics, McGill University, Montreal, QC, Canada
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Chan D, Oros Klein K, Riera-Escamilla A, Krausz C, O’Flaherty C, Chan P, Robaire B, Trasler JM. Sperm DNA methylome abnormalities occur both pre- and post-treatment in men with Hodgkin disease and testicular cancer. Clin Epigenetics 2023; 15:5. [PMID: 36611168 PMCID: PMC9826600 DOI: 10.1186/s13148-022-01417-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 12/21/2022] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Combination chemotherapy has contributed to increased survival from Hodgkin disease (HD) and testicular cancer (TC). However, questions concerning the quality of spermatozoa after treatment have arisen. While studies have shown evidence of DNA damage and aneuploidy in spermatozoa years following anticancer treatment, the sperm epigenome has received little attention. Our objectives here were to determine the impact of HD and TC, as well as their treatments, on sperm DNA methylation. Semen samples were collected from community controls (CC) and from men undergoing treatment for HD or TC, both before initiation of chemotherapy and at multiple times post-treatment. Sperm DNA methylation was assessed using genome-wide and locus-specific approaches. RESULTS Imprinted gene methylation was not affected in the sperm of HD or TC men, before or after treatment. Prior to treatment, using Illumina HumanMethylation450 BeadChip (450 K) arrays, a subset of 500 probes was able to distinguish sperm samples from TC, HD and CC subjects; differences between groups persisted post-treatment. Comparing altered sperm methylation between HD or TC patients versus CC men, twice as many sites were affected in TC versus HD men; for both groups, the most affected CpGs were hypomethylated. For TC patients, the promoter region of GDF2 contained the largest region of differential methylation. To assess alterations in DNA methylation over time/post-chemotherapy, serial samples from individual patients were compared. With restriction landmark genome scanning and 450 K array analyses, some patients who underwent chemotherapy showed increased alterations in DNA methylation, up to 2 to 3 years post-treatment, when compared to the CC cohort. Similarly, a higher-resolution human sperm-specific assay that includes assessment of environmentally sensitive regions, or "dynamic sites," also demonstrated persistently altered sperm DNA methylation in cancer patients post-treatment and suggested preferential susceptibility of "dynamic" CpG sites. CONCLUSIONS Distinct sperm DNA methylation signatures were present pre-treatment in men with HD and TC and may help explain increases in birth defects reported in recent clinical studies. Epigenetic defects in spermatozoa of some cancer survivors were evident even up to 2 years post-treatment. Abnormalities in the sperm epigenome both pre- and post-chemotherapy may contribute to detrimental effects on future reproductive health.
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Affiliation(s)
- Donovan Chan
- grid.63984.300000 0000 9064 4811Research Institute of the McGill University Health Centre, 1001 Décarie Boul. Block E, Montréal, QC Canada
| | - Kathleen Oros Klein
- grid.414980.00000 0000 9401 2774Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, QC Canada
| | - Antoni Riera-Escamilla
- grid.7080.f0000 0001 2296 0625Andrology Department, Fundació Puigvert, Universitat Autònoma de Barcelona, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Barcelona, Catalonia Spain
| | - Csilla Krausz
- grid.7080.f0000 0001 2296 0625Andrology Department, Fundació Puigvert, Universitat Autònoma de Barcelona, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Barcelona, Catalonia Spain ,grid.8404.80000 0004 1757 2304Department of Biomedical, Experimental and Clinical Sciences Mario Serio, University of Florence, Florence, Italy
| | - Cristian O’Flaherty
- grid.63984.300000 0000 9064 4811Research Institute of the McGill University Health Centre, 1001 Décarie Boul. Block E, Montréal, QC Canada ,grid.14709.3b0000 0004 1936 8649Department of Surgery, McGill University, Montréal, QC Canada ,grid.14709.3b0000 0004 1936 8649Department of Pharmacology and Therapeutics, McGill University, Montréal, QC Canada
| | - Peter Chan
- grid.63984.300000 0000 9064 4811Research Institute of the McGill University Health Centre, 1001 Décarie Boul. Block E, Montréal, QC Canada ,grid.14709.3b0000 0004 1936 8649Department of Urology, McGill University, Montréal, QC Canada
| | - Bernard Robaire
- grid.14709.3b0000 0004 1936 8649Department of Pharmacology and Therapeutics, McGill University, Montréal, QC Canada ,grid.14709.3b0000 0004 1936 8649Department of Obstetrics and Gynecology, McGill University, Montréal, QC Canada
| | - Jacquetta M. Trasler
- grid.63984.300000 0000 9064 4811Research Institute of the McGill University Health Centre, 1001 Décarie Boul. Block E, Montréal, QC Canada ,grid.14709.3b0000 0004 1936 8649Department of Pharmacology and Therapeutics, McGill University, Montréal, QC Canada ,grid.14709.3b0000 0004 1936 8649Departments of Pediatrics and Human Genetics, McGill University, Montréal, QC Canada
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L. Charest P, Tessougue E, Lessard M, Herst PM, Navarro P, Kimmins S, Trasler JM, MacFarlane AJ, Benoit-Biancamano MO, Bailey JL, Dalvai M. Exposure to environmental contaminants and folic acid supplementation intergenerationally impact fetal skeleton development through the paternal lineage in a rat model. Front Toxicol 2022; 4:881622. [PMID: 36238601 PMCID: PMC9552329 DOI: 10.3389/ftox.2022.881622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 08/26/2022] [Indexed: 11/13/2022] Open
Abstract
Persistent organic pollutants (POPs) are ubiquitous in the environment, which is of concern since they are broadly toxic for wildlife and human health. It is generally accepted that maternal prenatal folic acid supplementation (FA) may beneficially impact offspring development, but it has been recently shown that the father's exposures also influence the health of his offspring. Bone is an endocrine organ essential for whole-body homeostasis and is susceptible to toxicants. Herein, we tested the hypotheses that prenatal paternal exposure to POPs induces developmental bone disorders in fetuses across multiple generations and that FA supplementation attenuates these disorders. We used a four-generation rat model, in which F0 founder females were divided into four treatment groups. F0 females were gavaged with corn oil or an environmentally-relevant POPs mixture and fed either a control diet (2 mg FA/kg), or FA supplemented diet (6 mg FA/kg) before mating and until parturition (four treatments in total). After the birth of the F1 litters, all F0 females and subsequent generations received the FA control diet. Staining with alcian blue and alizarin red S of male and female fetal skeletons was performed at Gestational Day 19.5. Paternal direct and ancestral exposure to POPs delayed bone ossification and decreased the length of long limb bones in fetuses. Maternal FA supplementation did not counteract the POPs-associated delayed fetal ossification and reduced long bone length. In conclusion, prenatal paternal POPs exposure causes developmental bone abnormalities over multiple generations, which were not corrected by maternal FA supplementation.
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Affiliation(s)
- Phanie L. Charest
- Department of Animal Sciences, Faculty of Agricultural and Food Sciences, Université Laval, Quebec City, QC, Canada
- Centre de Recherche en Reproduction Développement et Santé Intergénérationnelle (CRDSI), Université Laval, Quebec City, QC, Canada
| | - Emmanuel Tessougue
- Department of Animal Sciences, Faculty of Agricultural and Food Sciences, Université Laval, Quebec City, QC, Canada
- Centre de Recherche en Reproduction Développement et Santé Intergénérationnelle (CRDSI), Université Laval, Quebec City, QC, Canada
| | - Maryse Lessard
- Department of Animal Sciences, Faculty of Agricultural and Food Sciences, Université Laval, Quebec City, QC, Canada
- Centre de Recherche en Reproduction Développement et Santé Intergénérationnelle (CRDSI), Université Laval, Quebec City, QC, Canada
| | - Pauline M. Herst
- Department of Animal Sciences, Faculty of Agricultural and Food Sciences, Université Laval, Quebec City, QC, Canada
- Centre de Recherche en Reproduction Développement et Santé Intergénérationnelle (CRDSI), Université Laval, Quebec City, QC, Canada
| | - Pauline Navarro
- Department of Nutrition, Faculty of Agricultural and Food Sciences, Institute of Nutrition and Functional Foods, Université Laval, Quebec City, QC, Canada
| | - Sarah Kimmins
- Department of Pharmacology and Therapeutics, Faculty of Medicine, McGill University, Montreal, QC, Canada
- Department of Animal Science, Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, QC, Canada
| | - Jacquetta M. Trasler
- Departments of Pediatrics, Human Genetics and Pharmacology and Therapeutics, Research Institute-McGill University Health Center, McGill University, Montreal, QC, Canada
| | | | - Marie-Odile Benoit-Biancamano
- Centre de Recherche en Reproduction Développement et Santé Intergénérationnelle (CRDSI), Université Laval, Quebec City, QC, Canada
- Groupe de Recherche En Pharmacologie Animale du Québec (GREPAQ), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, Sainte Hyacinthe, QC, Canada
| | - Janice L. Bailey
- Department of Animal Sciences, Faculty of Agricultural and Food Sciences, Université Laval, Quebec City, QC, Canada
- Centre de Recherche en Reproduction Développement et Santé Intergénérationnelle (CRDSI), Université Laval, Quebec City, QC, Canada
- *Correspondence: Janice L. Bailey, ; Mathieu Dalvai,
| | - Mathieu Dalvai
- Department of Animal Sciences, Faculty of Agricultural and Food Sciences, Université Laval, Quebec City, QC, Canada
- Centre de Recherche en Reproduction Développement et Santé Intergénérationnelle (CRDSI), Université Laval, Quebec City, QC, Canada
- *Correspondence: Janice L. Bailey, ; Mathieu Dalvai,
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Rahimi S, Martel J, Karahan G, Angle C, Behan NA, Chan D, MacFarlane AJ, Trasler JM. Moderate maternal folic acid supplementation ameliorates adverse embryonic and epigenetic outcomes associated with assisted reproduction in a mouse model. Hum Reprod 2020; 34:851-862. [PMID: 30989206 DOI: 10.1093/humrep/dez036] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 01/14/2019] [Indexed: 01/08/2023] Open
Abstract
STUDY QUESTION Could clinically-relevant moderate and/or high dose maternal folic acid supplementation prevent aberrant developmental and epigenetic outcomes associated with assisted reproductive technologies (ART)? SUMMARY ANSWER Our results demonstrate dose-dependent and sex-specific effects of folic acid supplementation in ART and provide evidence that moderate dose supplements may be optimal for both sexes. WHAT IS KNOWN ALREADY Children conceived using ART are at an increased risk for growth and genomic imprinting disorders, often associated with DNA methylation defects. Folic acid supplementation is recommended during pregnancy to prevent adverse offspring outcomes; however, the effects of folic acid supplementation in ART remain unclear. STUDY DESIGN, SIZE, DURATION Outbred female mice were fed three folic acid-supplemented diets, control (rodent daily recommended intake or DRI; CD), moderate (4-fold DRI; 4FASD) or high (10-fold DRI; 10FASD) dose, for six weeks prior to ART and throughout gestation. Mouse ART involved a combination of superovulation, in vitro fertilisation, embryo culture and embryo transfer. PARTICIPANTS/MATERIALS, SETTING, METHODS Midgestation embryos and placentas (n = 74-99/group) were collected; embryos were assessed for developmental delay and gross morphological abnormalities and embryos and placentas were examined for epigenetic defects. We assessed methylation at four imprinted genes (Snrpn, Kcnq1ot1, Peg1 and H19) in matched midgestation embryos and placentas (n = 31-32/group) using bisulfite pyrosequencing. In addition, we examined genome-wide DNA methylation patterns in placentas (n = 6 normal placentas per sex/group) and embryos (n = 6 normal female embryos/group; n = 3 delayed female embryos/group) using reduced representation bisulfite sequencing (RRBS). MAIN RESULTS AND THE ROLE OF CHANCE Moderate, but not high dose supplementation, was associated with a decrease in the proportion of developmentally delayed embryos. Although moderate dose folic acid supplementation reduced DNA methylation variance at certain imprinted genes in embryonic and placental tissues, high dose supplementation exacerbated the negative effects of ART at imprinted loci. Furthermore, folic acid supplements resolved female-biased aberrant imprinted gene methylation. Supplementation was more effective at correcting ART-induced genome-wide methylation defects in male versus female placentas; however, folic acid supplementation also led to additional methylation perturbations which were more pronounced in males. LARGE-SCALE DATA The RRBS data from this study have been submitted to the NCBI Gene Expression Omnibus under the accession number GSE123143. LIMITATIONS REASONS FOR CAUTION Although the combination of mouse ART utilised in this study consisted of techniques commonly used in human fertility clinics, there may be species differences. Therefore, human studies, designed to determine the optimal levels of folic acid supplementation for ART pregnancies, and taking into account foetal sex, are warranted. WIDER IMPLICATIONS OF THE FINDINGS Taken together, our findings support moderation in the dose of folic acid supplements taken during ART. STUDY FUNDING/COMPETING INTEREST(S) This work was funded by the Canadian Institutes of Health Research (FDN-148425). The authors declare no conflict of interest.
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Affiliation(s)
- Sophia Rahimi
- Child Health and Human Development Program (CHHD), Research Institute of the McGill University Health Centre, 1001 Décarie Boulevard, Montréal QC, Canada.,Department of Human Genetics, McGill University, 3640 rue University, Montréal QC, Canada
| | - Josée Martel
- Child Health and Human Development Program (CHHD), Research Institute of the McGill University Health Centre, 1001 Décarie Boulevard, Montréal QC, Canada
| | - Gurbet Karahan
- Child Health and Human Development Program (CHHD), Research Institute of the McGill University Health Centre, 1001 Décarie Boulevard, Montréal QC, Canada.,Department of Human Genetics, McGill University, 3640 rue University, Montréal QC, Canada
| | - Camille Angle
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montréal QC, Canada
| | - Nathalie A Behan
- Nutrition Research Division, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa ON, Canada
| | - Donovan Chan
- Child Health and Human Development Program (CHHD), Research Institute of the McGill University Health Centre, 1001 Décarie Boulevard, Montréal QC, Canada
| | - Amanda J MacFarlane
- Nutrition Research Division, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa ON, Canada
| | - Jacquetta M Trasler
- Child Health and Human Development Program (CHHD), Research Institute of the McGill University Health Centre, 1001 Décarie Boulevard, Montréal QC, Canada.,Department of Human Genetics, McGill University, 3640 rue University, Montréal QC, Canada.,Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montréal QC, Canada.,Department of Pediatrics, McGill University, 1001 Décarie Boulevard, Montréal QC, Canada
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McClatchie T, Meredith M, Ouédraogo MO, Slow S, Lever M, Mann MR, Zeisel SH, Trasler JM, Baltz JM. Correction: Betaine is accumulated via transient choline dehydrogenase activation during mouse oocyte meiotic maturation. J Biol Chem 2020; 295:10868. [DOI: 10.1074/jbc.aac120.015069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Herst PM, Dalvai M, Lessard M, Charest PL, Navarro P, Joly-Beauparlant C, Droit A, Trasler JM, Kimmins S, MacFarlane AJ, Benoit-Biancamano MO, Bailey JL. Folic acid supplementation reduces multigenerational sperm miRNA perturbation induced by in utero environmental contaminant exposure. Environ Epigenet 2019; 5:dvz024. [PMID: 31853372 PMCID: PMC6911352 DOI: 10.1093/eep/dvz024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/07/2019] [Accepted: 11/15/2019] [Indexed: 05/08/2023]
Abstract
Persistent organic pollutants (POPs) can induce epigenetic changes in the paternal germline. Here, we report that folic acid (FA) supplementation mitigates sperm miRNA profiles transgenerationally following in utero paternal exposure to POPs in a rat model. Pregnant founder dams were exposed to an environmentally relevant POPs mixture (or corn oil) ± FA supplementation and subsequent F1-F4 male descendants were not exposed to POPs and were fed the FA control diet. Sperm miRNA profiles of intergenerational (F1, F2) and transgenerational (F3, F4) lineages were investigated using miRNA deep sequencing. Across the F1-F4 generations, sperm miRNA profiles were less perturbed with POPs+FA compared to sperm from descendants of dams treated with POPs alone. POPs exposure consistently led to alteration of three sperm miRNAs across two generations, and similarly one sperm miRNA due to POPs+FA; which was in common with one POPs intergenerationally altered sperm miRNA. The sperm miRNAs that were affected by POPs alone are known to target genes involved in mammary gland and embryonic organ development in F1, sex differentiation and reproductive system development in F2 and cognition and brain development in F3. When the POPs treatment was combined with FA supplementation, however, these same miRNA-targeted gene pathways were perturbed to a lesser extend and only in F1 sperm. These findings suggest that FA partially mitigates the effect of POPs on paternally derived miRNA in a intergenerational manner.
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Affiliation(s)
- P M Herst
- Department of Animal Sciences, Faculty of Agricultural and Food Sciences, Centre de recherche en reproduction, développement et santé intergénérationnelle, Laval University, Quebec City, Canada
| | - M Dalvai
- Department of Animal Sciences, Faculty of Agricultural and Food Sciences, Centre de recherche en reproduction, développement et santé intergénérationnelle, Laval University, Quebec City, Canada
| | - M Lessard
- Department of Animal Sciences, Faculty of Agricultural and Food Sciences, Centre de recherche en reproduction, développement et santé intergénérationnelle, Laval University, Quebec City, Canada
| | - P L Charest
- Department of Animal Sciences, Faculty of Agricultural and Food Sciences, Centre de recherche en reproduction, développement et santé intergénérationnelle, Laval University, Quebec City, Canada
| | - P Navarro
- Department of Nutrition, Faculty of Agricultural and Food Sciences, Institute of Nutrition and Functional Foods, Centre de recherche en reproduction, développement et santé intergénérationnelle, Laval University, Quebec City, Canada
| | - C Joly-Beauparlant
- Computational Biology Laboratory Research Centre, Faculty of Medicine, Laval University, Quebec City, Canada
| | - A Droit
- Computational Biology Laboratory Research Centre, Faculty of Medicine, Laval University, Quebec City, Canada
| | - J M Trasler
- Departments of Pediatrics, Human Genetics and Pharmacology & Therapeutics, and The Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - S Kimmins
- Department of Pharmacology and Therapeutics, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
- Department of Animal Science, Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, Quebec, Canada
| | - A J MacFarlane
- Nutrition Research Division, Health Canada, Ottawa, Canada
| | - M-O Benoit-Biancamano
- Faculty of Veterinary Medicine, University of Montreal University, Saint-Hyacinthe, Quebec, Canada
| | - J L Bailey
- Department of Animal Sciences, Faculty of Agricultural and Food Sciences, Centre de recherche en reproduction, développement et santé intergénérationnelle, Laval University, Quebec City, Canada
- Correspondence address. Faculty of Agricultural and Food Sciences, Laval University, Pavillon Paul-Comtois, 2425, rue de l'Agriculture. Tel: +1-418-571-7034; Fax: +1-418- 656-3766; E-mail:
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Chan D, Shao X, Dumargne MC, Aarabi M, Simon MM, Kwan T, Bailey JL, Robaire B, Kimmins S, San Gabriel MC, Zini A, Librach C, Moskovtsev S, Grundberg E, Bourque G, Pastinen T, Trasler JM. Customized MethylC-Capture Sequencing to Evaluate Variation in the Human Sperm DNA Methylome Representative of Altered Folate Metabolism. Environ Health Perspect 2019; 127:87002. [PMID: 31393794 PMCID: PMC6792365 DOI: 10.1289/ehp4812] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
BACKGROUND The sperm DNA methylation landscape is unique and critical for offspring health. If gamete-derived DNA methylation escapes reprograming in early embryos, epigenetic defects in sperm may be transmitted to the next generation. Current techniques to assess sperm DNA methylation show bias toward CpG-dense regions and do not target areas of dynamic methylation, those predicted to be environmentally sensitive and tunable regulatory elements. OBJECTIVES Our goal was to assess variation in human sperm DNA methylation and design a targeted capture panel to interrogate the human sperm methylome. METHODS To characterize variation in sperm DNA methylation, we performed whole genome bisulfite sequencing (WGBS) on an equimolar pool of sperm DNA from a wide cross section of 30 men varying in age, fertility status, methylenetetrahydrofolate reductase (MTHFR) genotype, and exposures. With our targeted capture panel, in individual samples, we examined the effect of MTHFR genotype ([Formula: see text] 677CC, [Formula: see text] 677TT), as well as high-dose folic acid supplementation ([Formula: see text], per genotype, before and after supplementation). RESULTS Through WGBS we discovered nearly 1 million CpGs possessing intermediate methylation levels (20-80%), termed dynamic sperm CpGs. These dynamic CpGs, along with 2 million commonly assessed CpGs, were used to customize a capture panel for targeted interrogation of the human sperm methylome and test its ability to detect effects of altered folate metabolism. As compared with MTHFR 677CC men, those with the 677TT genotype (50% decreased MTHFR activity) had both hyper- and hypomethylation in their sperm. High-dose folic acid supplement treatment exacerbated hypomethylation in MTHFR 677TT men compared with 677CC. In both cases, [Formula: see text] of altered methylation was found in dynamic sperm CpGs, uniquely measured by our assay. DISCUSSION Our sperm panel allowed the discovery of differential methylation following conditions affecting folate metabolism in novel dynamic sperm CpGs. Improved ability to examine variation in sperm DNA methylation can facilitate comprehensive studies of environment-epigenome interactions. https://doi.org/10.1289/EHP4812.
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Affiliation(s)
- Donovan Chan
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Xiaojian Shao
- Canadian Centre for Computational Genomics, McGill University, Montreal, Quebec, Canada
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Marie-Charlotte Dumargne
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
- Department of Animal Sciences, McGill University, Montreal, Quebec, Canada
| | - Mahmoud Aarabi
- Medical Genetics & Genomics Laboratories, University of Pittsburgh Medical Center (UPMC) Magee-Womens Hospital, Pittsburgh, Pennsylvania, USA
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | | | - Tony Kwan
- McGill University and Génome Québec Innovation Centre, Montreal, Quebec, Canada
| | - Janice L. Bailey
- Centre de recherche en reproduction, développement et santé intergénérationnelle, Université Laval, Faculté des sciences de l’agriculture et de l’alimentation, Quebec, Quebec, Canada
| | - Bernard Robaire
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Sarah Kimmins
- Department of Animal Sciences, McGill University, Montreal, Quebec, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Maria C. San Gabriel
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
- Division of Urology, Department of Surgery, McGill University, Montreal, Quebec, Canada
| | - Armand Zini
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
- Division of Urology, Department of Surgery, McGill University, Montreal, Quebec, Canada
| | - Clifford Librach
- Canadian Reproductive Assisted Technology (CReATe) Fertility Centre, Toronto, Ontario, Canada
- Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, Canada
| | - Sergey Moskovtsev
- Canadian Reproductive Assisted Technology (CReATe) Fertility Centre, Toronto, Ontario, Canada
- Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, Canada
| | - Elin Grundberg
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
- Center for Pediatric Genomic Medicine, Children’s Mercy Kansas City, Kansas City, Missouri, USA
| | - Guillaume Bourque
- Canadian Centre for Computational Genomics, McGill University, Montreal, Quebec, Canada
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Tomi Pastinen
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
- Center for Pediatric Genomic Medicine, Children’s Mercy Kansas City, Kansas City, Missouri, USA
| | - Jacquetta M. Trasler
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
- Department of Pediatrics, McGill University, Montreal, Quebec, Canada
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9
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Whidden L, Martel J, Rahimi S, Chaillet JR, Chan D, Trasler JM. Compromised oocyte quality and assisted reproduction contribute to sex-specific effects on offspring outcomes and epigenetic patterning. Hum Mol Genet 2018; 25:4649-4660. [PMID: 28173052 DOI: 10.1093/hmg/ddw293] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/04/2016] [Accepted: 08/25/2016] [Indexed: 11/13/2022] Open
Abstract
Clinical studies have revealed an increased incidence of growth and genomic imprinting disorders in children conceived using assisted reproductive technologies (ARTs), and aberrant DNA methylation has been implicated. We propose that compromised oocyte quality associated with female infertility may make embryos more susceptible to the induction of epigenetic defects by ART. DNA methylation patterns in the preimplantation embryo are dependent on the oocyte-specific DNA methyltransferase 1o (DNMT1o), levels of which are decreased in mature oocytes of aging females. Here, we assessed the effects of maternal deficiency in DNMT1o (Dnmt1Δ1o/+) in combination with superovulation and embryo transfer on offspring DNA methylation and development. We demonstrated a significant increase in the rates of morphological abnormalities in offspring collected from Dnmt1Δ1o/+ females only when combined with ART. Together, maternal oocyte DNMT1o deficiency and ART resulted in an accentuation of placental imprinting defects and the induction of genome-wide DNA methylation alterations, which were exacerbated in the placenta compared to the embryo. Significant sex-specific trends were also apparent, with a preponderance of DNA hypomethylation in females. Among genic regions affected, a significant enrichment for neurodevelopmental pathways was observed. Taken together, our results demonstrate that oocyte DNMT1o-deficiency exacerbates genome-wide DNA methylation abnormalities induced by ART in a sex-specific manner and plays a role in mediating poor embryonic outcome.
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Affiliation(s)
- Laura Whidden
- Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Josée Martel
- Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Sophia Rahimi
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - J Richard Chaillet
- Department of OB/GYN and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Donovan Chan
- Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Jacquetta M Trasler
- Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada,Department of Human Genetics, McGill University, Montreal, QC, Canada,Department of Pediatrics, McGill University, Montreal, QC, Canada
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10
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McClatchie T, Meredith M, Ouédraogo MO, Slow S, Lever M, Mann MRW, Zeisel SH, Trasler JM, Baltz JM. Betaine is accumulated via transient choline dehydrogenase activation during mouse oocyte meiotic maturation. J Biol Chem 2017; 292:13784-13794. [PMID: 28663368 DOI: 10.1074/jbc.m117.803080] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Indexed: 11/06/2022] Open
Abstract
Betaine (N,N,N-trimethylglycine) plays key roles in mouse eggs and preimplantation embryos first in a novel mechanism of cell volume regulation and second as a major methyl donor in blastocysts, but its origin is unknown. Here, we determined that endogenous betaine was present at low levels in germinal vesicle (GV) stage mouse oocytes before ovulation and reached high levels in the mature, ovulated egg. However, no betaine transport into oocytes was detected during meiotic maturation. Because betaine can be synthesized in mammalian cells via choline dehydrogenase (CHDH; EC 1.1.99.1), we assessed whether this enzyme was expressed and active. Chdh transcripts and CHDH protein were expressed in oocytes. No CHDH enzyme activity was detected in GV oocyte lysate, but CHDH became highly active during oocyte meiotic maturation. It was again inactive after fertilization. We then determined whether oocytes synthesized betaine and whether CHDH was required. Isolated maturing oocytes autonomously synthesized betaine in vitro in the presence of choline, whereas this failed to occur in Chdh-/- oocytes, directly demonstrating a requirement for CHDH for betaine accumulation in oocytes. Overall, betaine accumulation is a previously unsuspected physiological process during mouse oocyte meiotic maturation whose underlying mechanism is the transient activation of CHDH.
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Affiliation(s)
- Taylor McClatchie
- From the Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada.,the Departments of Obstetrics and Gynecology and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario K1H 8M5, Canada
| | - Megan Meredith
- From the Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada.,the Departments of Obstetrics and Gynecology and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario K1H 8M5, Canada
| | - Mariame O Ouédraogo
- From the Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada.,the Departments of Obstetrics and Gynecology and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario K1H 8M5, Canada
| | - Sandy Slow
- the Department of Pathology, University of Otago, Christchurch 8140, New Zealand
| | - Michael Lever
- the Department of Chemistry, University of Canterbury, Christchurch 8041, New Zealand
| | - Mellissa R W Mann
- the Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213.,the Magee-Womens Research Institute, Pittsburgh, Pennsylvania 15213
| | - Steven H Zeisel
- the Department of Nutrition, Nutrition Research Institute, Gillings School of Global Public Health and School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Jacquetta M Trasler
- the Montréal Children's Hospital and Research Institute of the McGill University Health Centre, Montréal, Quebec H4A 3J1, Canada, and.,the Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec H3A 1B1, Canada
| | - Jay M Baltz
- From the Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada, .,the Departments of Obstetrics and Gynecology and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario K1H 8M5, Canada
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11
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Chan D, McGraw S, Klein K, Wallock LM, Konermann C, Plass C, Chan P, Robaire B, Jacob RA, Greenwood CMT, Trasler JM. Stability of the human sperm DNA methylome to folic acid fortification and short-term supplementation. Hum Reprod 2016; 32:272-283. [PMID: 27994001 DOI: 10.1093/humrep/dew308] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 10/26/2016] [Accepted: 11/07/2016] [Indexed: 12/24/2022] Open
Abstract
STUDY QUESTION Do short-term and long-term exposures to low-dose folic acid supplementation alter DNA methylation in sperm? SUMMARY ANSWER No alterations in sperm DNA methylation patterns were found following the administration of low-dose folic acid supplements of 400 μg/day for 90 days (short-term exposure) or when pre-fortification of food with folic acid and post-fortification sperm samples (long-term exposure) were compared. WHAT IS KNOWN ALREADY Excess dietary folate may be detrimental to health and DNA methylation profiles due to folate's role in one-carbon metabolism and the formation of S-adenosyl methionine, the universal methyl donor. DNA methylation patterns are established in developing male germ cells and have been suggested to be affected by high-dose (5 mg/day) folic acid supplementation. STUDY DESIGN, SIZE, DURATION This is a control versus treatment study where genome-wide sperm DNA methylation patterns were examined prior to fortification of food (1996-1997) in men with no history of infertility at baseline and following 90-day exposure to placebo (n = 9) or supplement containing 400 μg folic acid/day (n = 10). Additionally, pre-fortification sperm DNA methylation profiles (n = 19) were compared with those of a group of post-fortification (post-2004) men (n = 8) who had been exposed for several years to dietary folic acid fortification. PARTICIPANTS/MATERIALS, SETTING, METHODS Blood and seminal plasma folate levels were measured in participants before and following the 90-day treatment with placebo or supplement. Sperm DNA methylation was assessed using the whole-genome and genome-wide techniques, MassArray epityper, restriction landmark genomic scanning, methyl-CpG immunoprecipitation and Illumina HumanMethylation450 Bead Array. MAIN RESULTS AND THE ROLE OF CHANCE Following treatment, supplemented individuals had significantly higher levels of blood and seminal plasma folates compared to placebo. Initial first-generation genome-wide analyses of sperm DNA methylation showed little evidence of changes when comparing pre- and post-treatment samples. With Illumina HumanMethylation450 BeadChip arrays, no significant changes were observed in individual probes following low-level supplementation; when compared with those of the post-fortification cohort, there were also few differences in methylation despite exposure to years of fortified foods. LARGE SCALE DATA Illumina HumanMethylation450 BeadChip data from this study have been submitted to the NCBI Gene Expression Omnibus under the accession number GSE89781. LIMITATIONS, REASONS FOR CAUTION This study was limited to the number of participants available in each cohort, in particular those who were not exposed to early (pre-1998) fortification of food with folic acid. While genome-wide DNA methylation was assessed with several techniques that targeted genic and CpG-rich regions, intergenic regions were less well interrogated. WIDER IMPLICATIONS OF THE FINDINGS Overall, our findings provide evidence that short-term exposure to low-dose folic acid supplements of 400 μg/day, over a period of 3 months, a duration of time that might occur during infertility treatments, has no major impact on the sperm DNA methylome. STUDY FUNDING/COMPETING INTERESTS This work was supported by a grant to J.M.T. from the Canadian Institutes of Health Research (CIHR: MOP-89944). The authors have no conflicts of interest to declare.
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Affiliation(s)
- D Chan
- Departments of Pediatrics and of Human Genetics of McGill University, Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Glen Site, 1001 Décarie Boulevard Block E- Room EM0.2236 Montreal, QC H4A 3J1, Canada
| | - S McGraw
- Department of Obstetrics and Gynaecology, Biochemistry and Molecular Medicine of Université de Montréal, Research Center of the Sainte-Justine University Hospital, Montreal, QC H3T 1C5, Canada
| | - K Klein
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC H3T 1E2, Canada
| | - L M Wallock
- Department of Biological Sciences, Diablo Valley College, Pleasant Hill, CA 94523, USA
| | - C Konermann
- Department of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - C Plass
- Department of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - P Chan
- Royal Victoria Hospital of the McGill University Health Centre and Department of Surgery, McGill University, Montréal, QC H4A 3J1, Canada
| | - B Robaire
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC H3A 0G4, Canada
| | - R A Jacob
- USDA, Agricultural Research Service, Western Human Nutrition Research Center, Davis, CA 95616, USA
| | - C M T Greenwood
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC H3T 1E2, Canada.,Departments of Oncology, Epidemiology, Biostatistics and Occupational Health, and Human Genetics, McGill University, Montréal, QC H4A 3J1, Canada
| | - J M Trasler
- Departments of Pediatrics and of Human Genetics of McGill University, Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Glen Site, 1001 Décarie Boulevard Block E- Room EM0.2236 Montreal, QC H4A 3J1, Canada .,Department of Pharmacology and Therapeutics, McGill University, Montréal, QC H3A 0G4, Canada
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12
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Chaabane S, Sheehy O, Monnier P, Bissonnette F, Trasler JM, Fraser W, Bérard A. Ovarian Stimulators, Intrauterine Insemination, and Assisted Reproductive Technologies Use and the Risk of Major Congenital Malformations-The AtRISK Study. ACTA ACUST UNITED AC 2016; 107:136-47. [DOI: 10.1002/bdrb.21178] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 01/11/2023]
Affiliation(s)
- Sonia Chaabane
- Research Center; CHU Ste-Justine; Montreal Quebec Canada
- Faculty of Pharmacy; University of Montreal; Montreal Quebec Canada
| | - Odile Sheehy
- Research Center; CHU Ste-Justine; Montreal Quebec Canada
| | - Patricia Monnier
- Department of Obstetrics and Gynecology; Royal Victoria Hospital; University Reproductive Center; Montreal Quebec Canada
- Faculty of Medicine; McGill University; Montreal Quebec Canada
| | | | - Jacquetta M. Trasler
- Faculty of Medicine; McGill University; Montreal Quebec Canada
- Departments of Pediatrics; Human Genetics and Pharmacology & Therapeutics; McGill University; Montreal Quebec Canada
- Research Institute at the Montreal Children's Hospital; McGill University Health Centre; Montreal Quebec Canada
| | - William Fraser
- Department of Obstetrics and Gynecology; University of Sherbrooke, Sherbrooke; Quebec Canada
- Faculty of Medicine; University of Montreal; Quebec Canada
| | - Anick Bérard
- Research Center; CHU Ste-Justine; Montreal Quebec Canada
- Faculty of Pharmacy; University of Montreal; Montreal Quebec Canada
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13
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Meredith M, MacNeil AH, Trasler JM, Baltz JM. Growing Mouse Oocytes Transiently Activate Folate Transport via Folate Receptors As They Approach Full Size. Biol Reprod 2016; 94:125. [PMID: 27122634 PMCID: PMC4946804 DOI: 10.1095/biolreprod.115.137687] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 01/14/2016] [Accepted: 04/19/2016] [Indexed: 12/12/2022] Open
Abstract
The folate cycle is central to cellular one-carbon metabolism, where folates are carriers of one-carbon units that are critical for synthesis of purines, thymidylate, and S-adenosylmethionine, the universal methyl donor that forms the cellular methyl pool. Although folates are well-known to be important for early embryo and fetal development, their role in oogenesis has not been clearly established. Here, folate transport proteins were detected in developing neonatal ovaries and growing oocytes by immunohistochemistry, Western blot, and immunofluorescence. The folate receptors FOLR1 and FOLR2 as well as reduced folate carrier 1 (RFC1, SLC19A1 protein) each appeared to be present in follicular cells including granulosa cells. In growing oocytes, however, only FOLR2 immunoreactivity appeared abundant. Localization of apparent FOLR2 immunofluorescence near the plasma membrane increased with oocyte growth and peaked in oocytes as they neared full size. We assessed folate transport using the model folate leucovorin (folinic acid). Unexpectedly, there was a transient burst of folate transport activity for a brief period during oocyte growth as they neared full size, while folate transport was otherwise undetectable for the rest of oogenesis and in fully grown germinal vesicle stage oocytes. This folate transport was inhibited by dynasore, an inhibitor of endocytosis, but insensitive to the anion transport inhibitor stilbene 4-acetamido-40-isothiocyanato-stilbene-2,20-disulfonic acid, consistent with folate receptor-mediated transport but not with RFC1-mediated transport. Thus, near the end of their growth, growing oocytes may take up folates that could support the final stage of oogenesis or be stored to provide the endogenous folates needed in early embryogenesis.
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Affiliation(s)
- Megan Meredith
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada Department of Obstetrics and Gynecology and Department of Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
| | | | - Jacquetta M Trasler
- Montréal Children's Hospital and Research Institute of the McGill University Health Centre, Montréal, Quebec, Canada Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Jay M Baltz
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada Department of Obstetrics and Gynecology and Department of Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
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14
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McGraw S, Zhang JX, Farag M, Chan D, Caron M, Konermann C, Oakes CC, Mohan KN, Plass C, Pastinen T, Bourque G, Chaillet JR, Trasler JM. Transient DNMT1 suppression reveals hidden heritable marks in the genome. Nucleic Acids Res 2015; 43:1485-97. [PMID: 25578964 PMCID: PMC4330356 DOI: 10.1093/nar/gku1386] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Genome-wide demethylation and remethylation of DNA during early embryogenesis is essential for development. Imprinted germline differentially methylated domains (gDMDs) established by sex-specific methylation in either male or female germ cells, must escape these dynamic changes and sustain precise inheritance of both methylated and unmethylated parental alleles. To identify other, gDMD-like sequences with the same epigenetic inheritance properties, we used a modified embryonic stem (ES) cell line that emulates the early embryonic demethylation and remethylation waves. Transient DNMT1 suppression revealed gDMD-like sequences requiring continuous DNMT1 activity to sustain a highly methylated state. Remethylation of these sequences was also compromised in vivo in a mouse model of transient DNMT1 loss in the preimplantation embryo. These novel regions, possessing heritable epigenetic features similar to imprinted-gDMDs are required for normal physiological and developmental processes and when disrupted are associated with disorders such as cancer and autism spectrum disorders. This study presents new perspectives on DNA methylation heritability during early embryo development that extend beyond conventional imprinted-gDMDs.
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Affiliation(s)
- Serge McGraw
- Departments of Pediatrics, Human Genetics and Pharmacology & Therapeutics, McGill University and the Research Institute of the McGill University Health Centre at the Montreal Children's Hospital, Montreal, QC H3Z 2Z3, Canada
| | - Jacques X Zhang
- Departments of Pediatrics, Human Genetics and Pharmacology & Therapeutics, McGill University and the Research Institute of the McGill University Health Centre at the Montreal Children's Hospital, Montreal, QC H3Z 2Z3, Canada
| | - Mena Farag
- Departments of Pediatrics, Human Genetics and Pharmacology & Therapeutics, McGill University and the Research Institute of the McGill University Health Centre at the Montreal Children's Hospital, Montreal, QC H3Z 2Z3, Canada
| | - Donovan Chan
- Departments of Pediatrics, Human Genetics and Pharmacology & Therapeutics, McGill University and the Research Institute of the McGill University Health Centre at the Montreal Children's Hospital, Montreal, QC H3Z 2Z3, Canada
| | - Maxime Caron
- Department of Human Genetics, McGill University and Genome Quebec Innovation Centre, Montreal, QC H3A 1A4, Canada
| | - Carolin Konermann
- Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center, Heidelberg 69120, Germany
| | - Christopher C Oakes
- Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center, Heidelberg 69120, Germany
| | - K Naga Mohan
- Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad 500 078, India
| | - Christoph Plass
- Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center, Heidelberg 69120, Germany
| | - Tomi Pastinen
- Department of Human Genetics, McGill University and Genome Quebec Innovation Centre, Montreal, QC H3A 1A4, Canada
| | - Guillaume Bourque
- Department of Human Genetics, McGill University and Genome Quebec Innovation Centre, Montreal, QC H3A 1A4, Canada
| | - J Richard Chaillet
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15213-3005, USA
| | - Jacquetta M Trasler
- Departments of Pediatrics, Human Genetics and Pharmacology & Therapeutics, McGill University and the Research Institute of the McGill University Health Centre at the Montreal Children's Hospital, Montreal, QC H3Z 2Z3, Canada
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15
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Zhang B, Denomme MM, White CR, Leung KY, Lee MB, Greene NDE, Mann MRW, Trasler JM, Baltz JM. Both the folate cycle and betaine-homocysteine methyltransferase contribute methyl groups for DNA methylation in mouse blastocysts. FASEB J 2014; 29:1069-79. [PMID: 25466894 DOI: 10.1096/fj.14-261131] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The embryonic pattern of global DNA methylation is first established in the inner cell mass (ICM) of the mouse blastocyst. The methyl donor S-adenosylmethionine (SAM) is produced in most cells through the folate cycle, but only a few cell types generate SAM from betaine (N,N,N-trimethylglycine) via betaine-homocysteine methyltransferase (BHMT), which is expressed in the mouse ICM. Here, mean ICM cell numbers decreased from 18-19 in controls to 11-13 when the folate cycle was inhibited by the antifolate methotrexate and to 12-14 when BHMT expression was knocked down by antisense morpholinos. Inhibiting both pathways, however, much more severely affected ICM development (7-8 cells). Total SAM levels in mouse blastocysts decreased significantly only when both pathways were inhibited (from 3.1 to 1.6 pmol/100 blastocysts). DNA methylation, detected as 5-methylcytosine (5-MeC) immunofluorescence in isolated ICMs, was minimally affected by inhibition of either pathway alone but decreased by at least 45-55% when both BHMT and the folate cycle were inhibited simultaneously. Effects on cell numbers and 5-MeC levels in the ICM were completely rescued by methionine (immediate SAM precursor) or SAM. Both the folate cycle and betaine/BHMT appear to contribute to a methyl pool required for normal ICM development and establishing initial embryonic DNA methylation.
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Affiliation(s)
- Baohua Zhang
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Michelle M Denomme
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Carlee R White
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Kit-Yi Leung
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Martin B Lee
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Nicholas D E Greene
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Mellissa R W Mann
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Jacquetta M Trasler
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Jay M Baltz
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
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Fortier AL, McGraw S, Lopes FL, Niles KM, Landry M, Trasler JM. Modulation of imprinted gene expression following superovulation. Mol Cell Endocrinol 2014; 388:51-7. [PMID: 24631781 DOI: 10.1016/j.mce.2014.03.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 01/27/2014] [Accepted: 03/05/2014] [Indexed: 12/30/2022]
Abstract
Although assisted reproductive technologies increase the risk of low birth weight and genomic imprinting disorders, the precise underlying causes remain unclear. Using a mouse model, we previously showed that superovulation alters the expression of imprinted genes in the placenta at 9.5days (E9.5) of gestation. Here, we investigate whether effects of superovulation on genomic imprinting persisted at later stages of development and assess the surviving fetuses for growth and morphological abnormalities. Superovulation, followed by embryo transfer at E3.5, as compared to spontaneous ovulation (controls), resulted in embryos of normal size and weight at 14.5 and 18.5days of gestation. The normal monoallelic expression of the imprinted genes H19, Snrpn and Kcnq1ot1 was unaffected in either the placentae or the embryos from the superovulated females at E14.5 or E18.5. However, for the paternally expressed imprinted gene Igf2, superovulation generated placentae with reduced production of the mature protein at E9.5 and significantly more variable mRNA levels at E14.5. We propose that superovulation results in the ovulation of abnormal oocytes with altered expression of imprinted genes, but that the coregulated genes of the imprinted gene network result in modulated expression.
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Affiliation(s)
- Amanda L Fortier
- Research Institute at the Montreal Children's Hospital of the McGill University Health Centre and Department of Human Genetics, McGill University, Montreal, Quebec H3H 1P3, Canada
| | - Serge McGraw
- Research Institute at the Montreal Children's Hospital of the McGill University Health Centre and Department of Human Genetics, McGill University, Montreal, Quebec H3H 1P3, Canada; Research Institute at the Montreal Children's Hospital of the McGill University Health Centre and Department of Pediatrics, McGill University, Montreal, Quebec H3H 1P3, Canada
| | - Flavia L Lopes
- Research Institute at the Montreal Children's Hospital of the McGill University Health Centre and Department of Human Genetics, McGill University, Montreal, Quebec H3H 1P3, Canada; Research Institute at the Montreal Children's Hospital of the McGill University Health Centre and Department of Pediatrics, McGill University, Montreal, Quebec H3H 1P3, Canada
| | - Kirsten M Niles
- Research Institute at the Montreal Children's Hospital of the McGill University Health Centre and Department of Human Genetics, McGill University, Montreal, Quebec H3H 1P3, Canada
| | - Mylène Landry
- Research Institute at the Montreal Children's Hospital of the McGill University Health Centre and Department of Pediatrics, McGill University, Montreal, Quebec H3H 1P3, Canada
| | - Jacquetta M Trasler
- Research Institute at the Montreal Children's Hospital of the McGill University Health Centre and Department of Human Genetics, McGill University, Montreal, Quebec H3H 1P3, Canada; Research Institute at the Montreal Children's Hospital of the McGill University Health Centre and Department of Pediatrics, McGill University, Montreal, Quebec H3H 1P3, Canada; Research Institute at the Montreal Children's Hospital of the McGill University Health Centre and Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3H 1P3, Canada.
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17
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Corbett HE, Dubé CD, Slow S, Lever M, Trasler JM, Baltz JM. Uptake of Betaine into Mouse Cumulus-Oocyte Complexes via the SLC7A6 Isoform of y+L Transporter1. Biol Reprod 2014; 90:81. [DOI: 10.1095/biolreprod.113.116939] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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18
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McGraw S, Oakes CC, Martel J, Cirio MC, de Zeeuw P, Mak W, Plass C, Bartolomei MS, Chaillet JR, Trasler JM. Loss of DNMT1o disrupts imprinted X chromosome inactivation and accentuates placental defects in females. PLoS Genet 2013; 9:e1003873. [PMID: 24278026 PMCID: PMC3836718 DOI: 10.1371/journal.pgen.1003873] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 08/28/2013] [Indexed: 01/04/2023] Open
Abstract
The maintenance of key germline derived DNA methylation patterns during preimplantation development depends on stores of DNA cytosine methyltransferase-1o (DNMT1o) provided by the oocyte. Dnmt1omat−/− mouse embryos born to Dnmt1Δ1o/Δ1o female mice lack DNMT1o protein and have disrupted genomic imprinting and associated phenotypic abnormalities. Here, we describe additional female-specific morphological abnormalities and DNA hypomethylation defects outside imprinted loci, restricted to extraembryonic tissue. Compared to male offspring, the placentae of female offspring of Dnmt1Δ1o/Δ1o mothers displayed a higher incidence of genic and intergenic hypomethylation and more frequent and extreme placental dysmorphology. The majority of the affected loci were concentrated on the X chromosome and associated with aberrant biallelic expression, indicating that imprinted X-inactivation was perturbed. Hypomethylation of a key regulatory region of Xite within the X-inactivation center was present in female blastocysts shortly after the absence of methylation maintenance by DNMT1o at the 8-cell stage. The female preponderance of placental DNA hypomethylation associated with maternal DNMT1o deficiency provides evidence of additional roles beyond the maintenance of genomic imprints for DNA methylation events in the preimplantation embryo, including a role in imprinted X chromosome inactivation. During oocyte growth and maturation, vital proteins and enzymes are produced to ensure that, when fertilized, a healthy embryo will arise. When this natural process is interrupted, one or more of these essential elements can fail to be produced thus compromising the health of the future embryo. We are using a mouse model, lacking an enzyme (DNMT1o) produced in the oocyte and only required post-fertilization in the early embryo for the maintenance of inherited DNA methylation marks. Here, we reveal that oocytes lacking DNMT1o, when fertilized, generated conceptuses with a wide variety of placental abnormalities. These placental abnormalities were more frequent and severe in females, and showed specific genomic regions constantly deprived of their normal methylation marks. The affected genomic regions were concentrated on the X chromosome. Interestingly, we also found that a region important for the regulation of the X chromosome inactivation process was hypomethylated in female blastocysts and was associated with sex-specific abnormalities in the placenta, relaxation of imprinted X chromosome inactivation, and disruption of DNA methylation later in development. Our findings provide a novel unanticipated role for DNA methylation events taking place within the first few days of life specifically in female preimplantation embryos.
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Affiliation(s)
- Serge McGraw
- Departments of Pharmacology & Therapeutics, Pediatrics and Human Genetics, Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - Christopher C. Oakes
- Department of Epigenomics and Cancer Risk Factors, The German Cancer Research Center, Heidelberg, Baden-Württemberg, Germany
| | - Josée Martel
- Departments of Pharmacology & Therapeutics, Pediatrics and Human Genetics, Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - M. Cecilia Cirio
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Pauline de Zeeuw
- Departments of Pharmacology & Therapeutics, Pediatrics and Human Genetics, Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - Winifred Mak
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Christoph Plass
- Department of Epigenomics and Cancer Risk Factors, The German Cancer Research Center, Heidelberg, Baden-Württemberg, Germany
| | - Marisa S. Bartolomei
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - J. Richard Chaillet
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jacquetta M. Trasler
- Departments of Pharmacology & Therapeutics, Pediatrics and Human Genetics, Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada
- * E-mail:
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Garner JL, Niles KM, McGraw S, Yeh JR, Cushnie DW, Hermo L, Nagano MC, Trasler JM. Stability of DNA Methylation Patterns in Mouse Spermatogonia Under Conditions of MTHFR Deficiency and Methionine Supplementation1. Biol Reprod 2013; 89:125. [DOI: 10.1095/biolreprod.113.109066] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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Abstract
Endogenous folate stores are required in preimplantation embryos of several species, but how folates are accumulated and whether they can be replenished has not been determined. Folates are generally taken up into cells by specific transporters, mainly the reduced folate carrier RFC1 (SLC19A1 protein) and the high-affinity folate receptors FOLR1 and FOLR2. Quantitative RT-PCR showed that Slc19a1 mRNA was expressed in mouse cumulus-oocyte complexes (COCs) and oocytes, whereas Folr1 showed expression only in preimplantation embryos, increasing from the 2-cell stage onward. The mRNAs encoding Folr2 and the intestinal folate transporter Slc46a1 were not detected. Methotrexate (MTX), an antifolate often used as a model substrate for folate transport, exhibited saturable transport in COCs and in preimplantation embryos starting at the 2-cell stage. However, folate transport characteristics differed between COCs and embryos. In COCs, transport of MTX and the reduced folate leucovorin was inhibited by the anion transport inhibitor SITS that blocks RFC1 but was insensitive to dynasore, a specific dynamin inhibitor that instead inhibits folate receptor-receptor mediated endocytosis, whereas the opposite was found in 2-cell embryos and blastocysts. The inhibitor profile and transport properties of MTX and leucovorin in COCs correspond to established transport characteristics of RFC1 (SLC19A1), whereas those in 2-cell embryos and blastocysts correspond with those of FOLR1, consistent with the mRNA expression patterns. Considerable folate was accumulated in COCs via RFC1, but the presence of cumulus cells did not enhance folate accumulation in the enclosed oocyte, indicating a lack of transfer from cumulus to oocyte.
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Affiliation(s)
- Megan Kooistra
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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21
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Delbès G, Chan D, Hales BF, Trasler JM, Robaire B. Selective induction of glutathione S-transferases in round spermatids from the Brown-Norway rat by the chemotherapeutic regimen for testicular cancer. Reprod Toxicol 2012. [PMID: 23200778 DOI: 10.1016/j.reprotox.2012.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Chemotherapeutic drugs can affect DNA in male germ cells, thereby impacting on the integrity of the genome transmitted to offspring. Drug metabolizing enzymes can protect cells from xenobiotic insult. We analyzed the expression pattern of such enzymes in isolated round spermatids from rats exposed to drugs used to treat testicular cancer: bleomycin, etoposide, and cisplatin (BEP). The number of isozymes expressed and the overall relative expression values were highest for the glutathione S-transferases (GSTs). Moreover, BEP treatment significantly increased the expression of 8 GSTs and 3 aldehyde dehydrogenases. Increased expression of GST isozymes was confirmed by qRT-PCR and Western blot analysis. Although Gst genes can be targets for epigenetic modifications, promoter DNA methylation was not affected by BEP treatment. As GSTs are involved in drug resistance mechanisms, we hypothesize that BEP induction of GST expression may lead to the survival of damaged germ cells and the production of abnormal sperm.
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Affiliation(s)
- Geraldine Delbès
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
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22
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Niles KM, Yeh JR, Chan D, Landry M, Nagano MC, Trasler JM. Haploinsufficiency of the paternal-effect gene Dnmt3L results in transient DNA hypomethylation in progenitor cells of the male germline. Hum Reprod 2012; 28:519-30. [PMID: 23159436 DOI: 10.1093/humrep/des395] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
STUDY QUESTION How does haploinsufficiency of the paternal-effect gene Dnmt3L affect DNA methylation establishment and stability in the male germline? SUMMARY ANSWER Reduced expression of DNMT3L in male germ cells, associated with haploinsufficiency of the paternal-effect gene Dnmt3L, results in abnormal hypomethylation of prenatal germline progenitor cells. WHAT IS KNOWN ALREADY The DNA methyltransferase regulator Dnmt3-Like (Dnmt3L) is a paternal-effect gene required for DNA methylation acquisition in male germline stem cells and their precursors. In males, DNMT3L deficiency causes meiotic abnormalities and infertility. While Dnmt3L heterozygous males are fertile, they have abnormalities in X chromosome compaction and postmeiotic gene expression and sire offspring with sex chromosome aneuploidy. It has been proposed that the paternal effects of Dnmt3L haploinsufficiency are due to epigenetic defects in early male germ cells. DNA methylation is an essential epigenetic modification essential for normal germ cell development. Since patterns of DNA methylation across the genome are initially acquired in prenatal male germ cells, perturbations in methylation could contribute to the epigenetic basis of the paternal effects in Dnmt3L(+/-) males. STUDY DESIGN, SIZE, DURATION This is a cross-sectional study of DNA methylation in Dnmt3L(+/+) versus Dnmt3L(+/-) male germ cells collected from mice at 16.5 days post-coitum (dpc), Day 6 and Day 70 (n = 3 per genotype, each n represents a pool of 2-20 animals). Additionally, DNA methylation was compared in enriched populations of spermatogonial stem cells (SSC)/progenitor cells from Dnmt3L(+/+) and Dnmt3L(+/-) males following ≈ 2 months in culture. MATERIALS, SETTING, METHODS DNA methylation at intergenic loci along chromosomes 9 and X was examined by quantitative analysis of DNA methylation by real-time polymerase chain reaction at the time of initial acquisition of epigenetic patterns in the prenatal male germline (16.5 dpc) and compared with patterns in early post-natal spermatogonia (Day 6) and in spermatozoa in mice. DNA methylation status at CpG-rich sites across the genome was assessed in spermatogonial precursors from Day 4 male mice using restriction landmark genomic scanning. MAIN RESULTS AND THE ROLE OF CHANCE At 16.5 dpc, 42% of intergenic loci examined along chromosome 9 and 10% of those along chromosome X were hypomethylated in Dnmt3L heterozygotes. By Day 6 and in spermatozoa, germ cell DNA methylation was similar in heterozygous and wild-type mice. DNA methylation stability of acquired patterns in wild-type and Dnmt3L(+/-) SSC/progenitor cell culture was analyzed at numerous loci across the genome in cells cultured in vitro and collected at passages 6-28. While the methylation of most loci was stable in culture over time, differences at ≈ 1% of sites were found between Dnmt3L(+/-) and Dnmt3L(+/+) cultures. LIMITATIONS, REASONS FOR CAUTION Evaluation of DNA methylation in SSCs can only be performed after a period of culture limiting the investigation to changes observed during culture when compared with DNA methylation differences between genotypes that could be present at the beginning of culture establishment. WIDER IMPLICATIONS OF THE FINDINGS The DNA methylation defects described here in prenatal male germline progenitor cells and SSC culture are the earliest epigenetic perturbations yet identified for a mammalian paternal-effect gene and may influence downstream epigenetic events in germ cells at later stages of development. Together, the results provide evidence of a 'window' of susceptibility in prenatal male germ cell precursors for the induction of epimutations due to genetic perturbations and, potentially, in utero environmental exposures.
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Affiliation(s)
- K M Niles
- Department of Human Genetics, McGill University, Montréal, Quebec, Canada
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23
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Lee MB, Kooistra M, Zhang B, Slow S, Fortier AL, Garrow TA, Lever M, Trasler JM, Baltz JM. Betaine homocysteine methyltransferase is active in the mouse blastocyst and promotes inner cell mass development. J Biol Chem 2012; 287:33094-103. [PMID: 22847001 DOI: 10.1074/jbc.m112.365478] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Methyltransferases are an important group of enzymes with diverse roles that include epigenetic gene regulation. The universal donor of methyl groups for methyltransferases is S-adenosylmethionine (AdoMet), which in most cells is synthesized using methyl groups carried by a derivative of folic acid. Another mechanism for AdoMet synthesis uses betaine as the methyl donor via the enzyme betaine-homocysteine methyltransferase (BHMT, EC 2.1.1.5), but it has been considered to be significant only in liver. Here, we show that mouse preimplantation embryos contain endogenous betaine; Bhmt mRNA is first expressed at the morula stage; BHMT is abundant at the blastocyst stage but not other preimplantation stages, and BHMT activity is similarly detectable in blastocyst homogenates but not those of two-cell or morula stage embryos. Knockdown of BHMT protein levels and reduction of enzyme activity using Bhmt-specific antisense morpholinos or a selective BHMT inhibitor resulted in decreased development of embryos to the blastocyst stage in vitro and a reduction in inner cell mass cell number in blastocysts. The detrimental effects of BHMT knockdown were fully rescued by the immediate methyl-carrying product of BHMT, methionine. A physiological role for betaine and BHMT in blastocyst viability was further indicated by increased fetal resorption following embryo transfer of BHMT knockdown blastocysts versus control. Thus, mouse blastocysts are unusual in being able to generate AdoMet not only by the ubiquitous folate-dependent mechanism but also from betaine metabolized by BHMT, likely a significant pool of methyl groups in blastocysts.
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Affiliation(s)
- Martin B Lee
- Ottawa Hospital Research Institute, Ottawa, Ontario K1Y4E9, Canada
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24
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Chan D, Delbès G, Landry M, Robaire B, Trasler JM. Epigenetic alterations in sperm DNA associated with testicular cancer treatment. Toxicol Sci 2011; 125:532-43. [PMID: 22076425 DOI: 10.1093/toxsci/kfr307] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
DNA methylation, a key component of the epigenome involved in regulating gene expression, is initially acquired in the germ line at millions of sites across the genome. Altered sperm methylation patterns are associated with infertility and transgenerational effects in humans and rodents. Testicular cancer is the most common form of cancer among men of reproductive age and has a high cure rate associated with chemotherapy treatment with bleomycin, etoposide, and cis-platinum (BEP). Although these drugs result in improved survival, they also affect the number and quality of germ cells. Our goal was to assess germ cell methylation patterns in a rodent model emulating the BEP treatment regimens used in human testicular cancer treatment. Animals were treated with control, or 0.3× (low) or 0.6× (high) dose of BEP, where a 1× dose is equivalent to human treatment regimens. Both dose-dependent and germ cell-dependent DNA methylation alterations were found at numerous loci throughout the genome. Of about 3000 loci tested, 42 loci were affected by BEP at the round spermatid stage of germ cell development, whereas 101 loci were affected in spermatozoa; 15 loci were consistently altered in spermatozoa of all high dose-treated rats. Both hyper- and hypomethylation were detected, suggesting either an interference with normal methylation patterning or abnormal repair of damaged patterns during spermatogenesis. The results indicate that a combination chemotherapy regimen used for testicular cancer treatment can result in altered DNA methylation patterns in spermatozoa and that some loci are more susceptible to damage than others.
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Affiliation(s)
- Donovan Chan
- Research Institute of the McGill University Health Centre at Montreal Children's Hospital, Montreal, Quebec H3Z 2Z3, Canada
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Niles KM, Chan D, La Salle S, Oakes CC, Trasler JM. Critical period of nonpromoter DNA methylation acquisition during prenatal male germ cell development. PLoS One 2011; 6:e24156. [PMID: 21949694 PMCID: PMC3176233 DOI: 10.1371/journal.pone.0024156] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 08/01/2011] [Indexed: 12/14/2022] Open
Abstract
The prenatal period of germ cell development is a key time of epigenetic programming in the male, a window of development that has been shown to be influenced by maternal factors such as dietary methyl donor supply. DNA methylation occurring outside of promoter regions differs significantly between sperm and somatic tissues and has recently been linked with the regulation of gene expression during development as well as successful germline development. We examined DNA methylation at nonpromoter, intergenic sequences in purified prenatal and postnatal germ cells isolated from wildtype mice and mice deficient in the DNA methyltransferase cofactor DNMT3L. Erasure of the parental DNA methylation pattern occurred by 13.5 days post coitum (dpc) with the exception of approximately 8% of loci demonstrating incomplete erasure. For most loci, DNA methylation acquisition occurred between embryonic day 13.5 to 16.5 indicating that the key phase of epigenetic pattern establishment for intergenic sequences in male germ cells occurs prior to birth. In DNMT3L-deficient germ cells at 16.5 dpc, average DNA methylation levels were low, about 30% of wildtype levels; however, by postnatal day 6, about half of the DNMT3L deficiency-specific hypomethylated loci had acquired normal methylation levels. Those loci normally methylated earliest in the prenatal period were the least affected in the DNMT3L-deficient mice, suggesting that some loci may be more susceptible than others to perturbations occurring prenatally. These results indicate that the critical period of DNA methylation programming of nonpromoter, intergenic sequences occurs in male germline progenitor cells in the prenatal period, a time when external perturbations of epigenetic patterns could result in diminished fertility.
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Affiliation(s)
- Kirsten M. Niles
- Departments of Pharmacology and Therapeutics, Pediatrics and Human Genetics, McGill University and Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, Montréal, Quebec, Canada
| | - Donovan Chan
- Departments of Pharmacology and Therapeutics, Pediatrics and Human Genetics, McGill University and Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, Montréal, Quebec, Canada
| | - Sophie La Salle
- Departments of Pharmacology and Therapeutics, Pediatrics and Human Genetics, McGill University and Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, Montréal, Quebec, Canada
| | - Christopher C. Oakes
- Departments of Pharmacology and Therapeutics, Pediatrics and Human Genetics, McGill University and Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, Montréal, Quebec, Canada
| | - Jacquetta M. Trasler
- Departments of Pharmacology and Therapeutics, Pediatrics and Human Genetics, McGill University and Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, Montréal, Quebec, Canada
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Chan D, Cushnie DW, Neaga OR, Lawrance AK, Rozen R, Trasler JM. Strain-specific defects in testicular development and sperm epigenetic patterns in 5,10-methylenetetrahydrofolate reductase-deficient mice. Endocrinology 2010; 151:3363-73. [PMID: 20444942 DOI: 10.1210/en.2009-1340] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Methylenetetrahydrofolate reductase (MTHFR) is a crucial folate pathway enzyme that contributes to the maintenance of cellular pools of S-adenosylmethionine, the universal methyl donor for several reactions including DNA methylation. Whereas Mthfr(-/-) BALB/c mice show growth retardation, developmental delay, and spermatogenic defects and infertility, C57BL/6 mice appear to have a less severe phenotype. In the present study, we investigated the effects of MTHFR deficiency on early germ cell development in both strains and assessed whether MTHFR deficiency results in DNA methylation abnormalities in sperm. The reproductive phenotype associated with MTHFR deficiency differed strikingly between the two strains, with BALB/c mice showing an early postnatal loss of germ cell number and proliferation that was not evident in the C57BL/6 mice. As a result, the BALB/c MTHFR-deficient mice were infertile, whereas the C57BL/6 mice had decreased sperm numbers and altered testicular histology but showed normal fertility. Imprinted genes and sequences that normally become methylated during spermatogenesis were unaffected by MTHFR deficiency in C57BL/6 mice. In contrast, a genome-wide restriction landmark genomic scanning approach revealed a number of sites of hypo- and hypermethylation in the sperm of this mouse strain. These results showing strain-specific defects in MTHFR-deficient mice may help to explain population differences in infertility among men with common MTHFR polymorphisms.
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Affiliation(s)
- Donovan Chan
- Montréal Children's Hospital Research Institute, 2300 Tupper Street, Montréal, Québec, Canada H3H 1P3
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Abstract
DNA methylation is a heritable epigenetic modification of cytosine residues within CpG dinucleotides associated with the modulation of gene expression and found at 20-30 million sites throughout the mammalian genome. The methylation of DNA is catalyzed by DNA (cytosine-5)-methyltransferases (DNMTs), regulates genes during development and plays a role in genomic imprinting and X inactivation. Abnormalities in DNA methylation lead to growth and behavioral abnormalities as well as cancer. Genomic methylation patterns are acquired in the germline and then further modified during embryogenesis. Methylation in the male germline is unique in comparison to that in somatic tissues, begins in the fetal gonad before birth, and is completed during postnatal spermatogenesis. In rodents, altered expression of the DNMTs through gene-targeting or drug treatment is associated with abnormal DNA methylation patterns in germ cells and perturbations in spermatogenesis. In man altered sperm DNA methylation patterns have been reported in individuals with oligospermia.
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Affiliation(s)
- Jacquetta M Trasler
- Departments of Pediatrics, McGill University, Montreal Children's Hospital, McGill University Health Centre Research Institute, Montreal, QC, Canada.
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Trasler JM. Setting Epigenetic Programs in the Early Germline--Role of DNA Methyltransferases and Folate Pathway Enzymes.Jacquetta Trasler, M.D., Ph.D. Biol Reprod 2009. [DOI: 10.1093/biolreprod/81.s1.60] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Loewy AD, Niles KM, Anastasio N, Watkins D, Lavoie J, Lerner-Ellis JP, Pastinen T, Trasler JM, Rosenblatt DS. Epigenetic modification of the gene for the vitamin B(12) chaperone MMACHC can result in increased tumorigenicity and methionine dependence. Mol Genet Metab 2009; 96:261-7. [PMID: 19200761 DOI: 10.1016/j.ymgme.2008.12.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 12/17/2008] [Indexed: 01/12/2023]
Abstract
Methionine dependence, the inability of cells to grow when the amino acid methionine is replaced in culture medium by its metabolic precursor homocysteine, is characteristic of many cancer cell lines and some tumors in situ. Most cell lines proliferate normally under these conditions. The methionine dependent tumorigenic human melanoma cell line MeWo-LC1 was derived from the methionine independent non-tumorigenic line, MeWo. MeWo-LC1 has a cellular phenotype identical to that of cells from patients with the cblC inborn error of cobalamin metabolism, with decreased synthesis of cobalamin coenzymes and decreased activity of the cobalamin-dependent enzymes methionine synthase and methylmalonylCoA mutase. Inability of cblC cells to complement the defect in MeWo-LC1 suggested that it was caused by decreased activity of the MMACHC gene. However, no potentially disease causing mutations were detected in the coding sequence of MMACHC in MeWo-LC1. No MMACHC expression was detected in MeWo-LC1 by quantitative or non-quantitative PCR. There was virtually complete methylation of a CpG island at the 5'-end of the MMACHC gene in MeWo-LC1, consistent with inactivation of the gene by methylation. The CpG island was partially methylated (30-45%) in MeWo and only lightly methylated (2-11%) in control fibroblasts. Infection of MeWo-LC1 with wild type MMACHC resulted in correction of the defect in cobalamin metabolism and restoration of the ability of cells to grow in medium containing homocysteine. We conclude that epigenetic inactivation of the MMACHC gene is responsible for methionine dependence in MeWo-LC1.
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Affiliation(s)
- Amanda D Loewy
- Department of Human Genetics, McGill University, McGill University Health Centre, Montreal General Hospital, 1650 Cedar Ave, Room L3.319, Montreal, Que., Canada H3G 1A4
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Lopes FL, Fortier AL, Darricarrère N, Chan D, Arnold DR, Trasler JM. Reproductive and epigenetic outcomes associated with aging mouse oocytes. Hum Mol Genet 2009; 18:2032-44. [DOI: 10.1093/hmg/ddp127] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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31
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Abstract
DNA methylation in mammals has been shown to play many important roles in diverse biological phenomena. Here we describe a simple and straightforward method that quantitatively measures site-specific levels of DNA methylation in a quick and cost-effective manner. The quantitative analysis of DNA methylation using real-time PCR (qAMP) technique involves the digestion of genomic DNA using methylation-sensitive and methylation-dependent restriction enzymes followed by real-time PCR. This approach generates accurate and reproducible results without the requirement for prior treatment of the DNA with sodium bisulfite.
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Affiliation(s)
- Christopher C Oakes
- Department of Pharmacology and Therapeutics and The Montreal Children's Hospital Research Institute, McGill University, Quebec, Montreal, Canada
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32
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Delbès G, Chan D, Pakarinen P, Trasler JM, Hales BF, Robaire B. Impact of the chemotherapy cocktail used to treat testicular cancer on the gene expression profile of germ cells from male Brown-Norway rats. Biol Reprod 2008; 80:320-7. [PMID: 18987330 DOI: 10.1095/biolreprod.108.072108] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Advances in treatment for testicular cancer that include the coadministration of bleomycin, etoposide, and cisplatin (BEP) have brought the cure rate to higher than 90%%. The goal of this study was to elucidate the impact of BEP treatment on gene expression in male germ cells. Brown-Norway rats were treated for 9 wk with vehicle (0x) or BEP at doses equivalent to 0.3x and 0.6x the human dose. At the end of treatment, spermatogenesis was affected, showing altered histology and a decreased sperm count; spermatozoa had a higher number of DNA breaks. After 9 wk of treatment, round spermatids were isolated, and RNA was extracted and probed on Rat230-2.0 Affymetrix arrays. Of the 31 099 probe sets present on the array, 59%% were expressed in control round spermatids. BEP treatment significantly altered the expression of 221 probe sets, with at least a 1.5-fold change compared with controls; 80% were upregulated. We observed a dose-dependent increase in the expression of oxidative stress response genes and no change in the expression of genes involved in DNA repair. BEP upregulated genes were implicated in pathways related to Jun and Junb protooncogenes. Increased mRNA levels of Jun and Junb were confirmed by quantitative RT-PCR; furthermore, JUN protein was increased in elongating spermatids. Thus, BEP exposure triggers an oxidative stress response in round spermatids and induces many pathways that may lead to the survival of damaged cells and production of abnormal sperm.
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Affiliation(s)
- Geraldine Delbès
- Department of Pharmacology and Therapeutics, McGill University, Montreal Children's Hospital Research Institute, Montréal, Québec, Canada H3G 1Y6
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Martel J, Fortier A, Lopes F, Cirio C, Chaillet RJ, Trasler JM. The Absence of the Oocyte-derived Dnmt1o Protein Leads to Anatomical and Molecular Abnormalities in Placentae. Biol Reprod 2008. [DOI: 10.1093/biolreprod/78.s1.66a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Fortier AL, Lopes FL, Darricarrère N, Martel J, Trasler JM. Superovulation alters the expression of imprinted genes in the midgestation mouse placenta. Hum Mol Genet 2008; 17:1653-65. [PMID: 18287259 DOI: 10.1093/hmg/ddn055] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Imprinted genes play important roles in embryonic growth and development as well as in placental function. Many imprinted genes acquire their epigenetic marks during oocyte growth, and this period may be susceptible to epigenetic disruption following hormonal stimulation. Superovulation has been shown to affect growth and development of the embryo, but an effect on imprinted genes has not been shown in postimplantation embryos. In the present study, we examined the effect of superovulation/in vivo development or superovulation/3.5dpc (days post-coitum) embryo transfer on the allelic expression of Snrpn, Kcnq1ot1 and H19 in embryos and placentas at 9.5 days of gestation. Superovulation followed by in vivo development resulted in biallelic expression of Snrpn and H19 in 9.5dpc placentas while Kcnq1ot1 was not affected; in the embryos, there was normal monoallelic expression of the three imprinted genes. We did not observe significant DNA methylation perturbations in the differentially methylated regions of Snrpn or H19. Superovulation followed by embryo transfer at 3.5dpc resulted in biallelic expression of H19 in the placenta. The expression of an important growth factor closely linked to H19, Insulin-like growth factor-II, was increased in the placenta following superovulation with or without embryo transfer. These results show that both maternally and paternally methylated imprinted genes were affected, suggesting that superovulation compromises oocyte quality and interferes with the maintenance of imprinting during preimplantation development. Our findings contribute to the evidence that mechanisms for maintaining imprinting are less robust in trophectoderm-derived tissues, and have clinical implications for the screening of patients following assisted reproduction.
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Affiliation(s)
- Amanda L Fortier
- Department of Human Genetics, McGill University, Montreal Children's Hospital Research Institute, Montreal, Quebec, Canada
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35
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Toppings M, Castro C, Mills PH, Reinhart B, Schatten G, Ahrens ET, Chaillet JR, Trasler JM. Profound phenotypic variation among mice deficient in the maintenance of genomic imprints. Hum Reprod 2008; 23:807-18. [PMID: 18276606 DOI: 10.1093/humrep/den009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND An alteration in the mechanism that maintains the monoallelic, imprinted expression of genes can result in their biallelic expression and lead to disruptions in fetal development. Here, we examined the consequences of a loss of maintenance methylation at one specific stage of preimplantation, induced by a deficiency of the oocyte-derived Dnmt1o protein and known to produce biallelic expression of imprinted genes. METHODS Phenotypes of mid-gestation Dnmt1o-deficient mouse embryos were assessed by a scoring system based on the developmental stage of 17 anatomical features and by magnetic resonance microscopy. RESULTS Many mid-gestation embryos developing without Dnmt1o protein exhibited significant developmental delays of multiple organ systems (P < 0.05) and a wide variety of morphologic anomalies compared with wild-type embryos. Most of the remaining mid-gestation Dnmt1o-deficient embryos appeared normal. CONCLUSIONS These findings indicate that a profound range of gestational phenotypes can be induced by the loss of a single protein at a specific preimplantation developmental stage. This is best explained by the formation of epigenetic mosaic early embryos, composed of somatic cells with different spectra of normal intact genomic imprints. These findings have important implications for understanding the types of embryonic phenotypes related to the disruption of inherited imprints, and thus may provide a model of altered imprinting in humans. In particular, because Dnmt1o functions in the preimplantation embryo, a complete or partial loss of Dnmt1o function may play a role in epigenetic abnormalities seen in assisted reproduction technology births.
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Affiliation(s)
- Marc Toppings
- McGill University-Montreal Children's Hospital Research Institute, Montreal, Quebec, Canada H3H 1P3
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36
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La Salle S, Oakes CC, Neaga OR, Bourc'his D, Bestor TH, Trasler JM. Loss of spermatogonia and wide-spread DNA methylation defects in newborn male mice deficient in DNMT3L. BMC Dev Biol 2007; 7:104. [PMID: 17875220 PMCID: PMC2212652 DOI: 10.1186/1471-213x-7-104] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Accepted: 09/18/2007] [Indexed: 12/13/2022]
Abstract
BACKGROUND Formation of haploid spermatozoa capable of fertilization requires proper programming of epigenetic information. Exactly how DNMT3L (DNA methyltransferase 3-Like), a postulated regulator of DNA methyltransferase activity, contributes to DNA methylation pattern acquisition during gametogenesis remains unclear. Here we report on the role of DNMT3L in male germ cell development. RESULTS A developmental study covering the first 12 days following birth was conducted on a Dnmt3L mutant mouse model; lower germ cell numbers and delayed entry into meiosis were observed in Dnmt3L-/- males, pointing to a mitotic defect. A temporal expression study showed that expression of Dnmt3L is highest in prenatal gonocytes but is also detected and developmentally regulated during spermatogenesis. Using a restriction enzyme qPCR assay (qAMP), DNA methylation analyses were conducted on postnatal primitive type A spermatogonia lacking DNMT3L. Methylation levels along 61 sites across chromosomes 4 and X decreased significantly by approximately 50% compared to the levels observed in Dnmt3L+/+ germ cells, suggesting that many loci throughout the genome are marked for methylation by DNMT3L. More so, hypomethylation was more pronounced in regions of lower GC content than in regions of higher GC content. CONCLUSION Taken together, these data suggest that DNMT3L plays a more global role in genomic methylation patterning than previously believed.
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Affiliation(s)
- Sophie La Salle
- Departments of Pharmacology & Therapeutics, Pediatrics and Human Genetics, McGill University and The Montreal Children's Hospital Research Institute, Montréal, QC, H3H 1P3, Canada
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Christopher C Oakes
- Departments of Pharmacology & Therapeutics, Pediatrics and Human Genetics, McGill University and The Montreal Children's Hospital Research Institute, Montréal, QC, H3H 1P3, Canada
| | - Oana R Neaga
- Departments of Pharmacology & Therapeutics, Pediatrics and Human Genetics, McGill University and The Montreal Children's Hospital Research Institute, Montréal, QC, H3H 1P3, Canada
| | | | - Timothy H Bestor
- Department of Genetics and Development, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | - Jacquetta M Trasler
- Departments of Pharmacology & Therapeutics, Pediatrics and Human Genetics, McGill University and The Montreal Children's Hospital Research Institute, Montréal, QC, H3H 1P3, Canada
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Oakes CC, Kelly TLJ, Robaire B, Trasler JM. Adverse Effects of 5-Aza-2′-Deoxycytidine on Spermatogenesis Include Reduced Sperm Function and Selective Inhibition of de Novo DNA Methylation. J Pharmacol Exp Ther 2007; 322:1171-80. [PMID: 17581917 DOI: 10.1124/jpet.107.121699] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The anticancer agent, 5-aza-2'-deoxycytidine (5-azaCdR, decitabine), causes DNA hypomethylation and a robust, dose-dependent disruption of spermatogenesis. Previously, we have shown that altered testicular histology and reduced sperm production in 5-azaCdR-treated animals is associated with decreased global sperm DNA methylation and an increase in infertility and/or a decreased ability to support preimplantation embryonic development. The goal of this study was to determine potential contributors to 5-azaCdR-mediated infertility including alterations in sperm motility, fertilization ability, early embryo development, and sequence-specific DNA methylation. We find that although 5-azaCdR-treatment adversely affected sperm motility and the survival of sired embryos to the blastocyst stage, the major contributor to infertility was a marked (56-70%) decrease in fertilization ability. Sperm DNA methylation was investigated using Southern blot, restriction landmark genomic scanning, and quantitative analysis of DNA methylation by real-time polymerase chain reaction. Interestingly, hypomethylation was restricted to genomic loci that have been previously determined to acquire methylation during spermatogenesis, demonstrating that 5-azaCdR selectively inhibits de novo methylation activity. Similar to previous studies, we show that mice that are heterozygous for a nonfunctional Dnmt1 gene are partially protected against the deleterious effects of 5-azaCdR; however, methylation levels are not restored in these mice, suggesting that adverse effects are due to another mechanism(s) in addition to DNA hypomethylation. These results demonstrate that clinically relevant doses of 5-azaCdR specifically impair de novo methylation activity in male germ cells; however, genotype-specific differences in drug responses suggest that adverse reproductive outcomes are mainly mediated by the cytotoxic properties of the drug.
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Affiliation(s)
- Christopher C Oakes
- Department of Pharmacology and Therapeutics, McGill University-Montreal Children's Hospital Research Institute, 2300 Tupper St., Montreal, QC, Canada
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38
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Fortier AL, Lopes FL, Martel J, Trasler JM. The effect of superovulation on methylation and expression of imprinted genes in pre- and post-implantation mouse embryos. Dev Biol 2007. [DOI: 10.1016/j.ydbio.2007.03.371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Oakes CC, La Salle S, Smiraglia DJ, Robaire B, Trasler JM. Developmental acquisition of genome-wide DNA methylation occurs prior to meiosis in male germ cells. Dev Biol 2007; 307:368-79. [PMID: 17559830 DOI: 10.1016/j.ydbio.2007.05.002] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Revised: 04/01/2007] [Accepted: 05/01/2007] [Indexed: 02/05/2023]
Abstract
The development of germ cells is a highly ordered process that begins during fetal growth and is completed in the adult. Epigenetic modifications that occur in germ cells are important for germ cell function and for post-fertilization embryonic development. We have previously shown that male germ cells in the adult mouse have a highly distinct epigenetic state, as revealed by a unique genome-wide pattern of DNA methylation. Although it is known that these patterns begin to be established during fetal life, it is not known to what extent DNA methylation is modified during spermatogenesis. We have used restriction landmark genomic scanning (RLGS) and other techniques to examine DNA methylation at multiple sites across the genome during postnatal germ cell development in the mouse. Although a significant proportion of the distinct germ cell pattern is acquired prior to the type A spermatogonial stage, we find that both de novo methylation and demethylation occur during spermatogenesis, mainly in spermatogonia and spermatocytes in early meiotic prophase I. Alterations include predominantly non-CpG island sequences from both unique loci and repetitive elements. These modifications are progressive and are almost exclusively completed by the end of the pachytene spermatocyte stage. These studies better define the developmental timing of genome-wide DNA methylation pattern acquisition during male germ cell development.
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Affiliation(s)
- C C Oakes
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
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Kishta O, Adeeko A, Li D, Luu T, Brawer JR, Morales C, Hermo L, Robaire B, Hales BF, Barthelemy J, Cyr DG, Trasler JM. In utero exposure to tributyltin chloride differentially alters male and female fetal gonad morphology and gene expression profiles in the Sprague–Dawley rat. Reprod Toxicol 2007; 23:1-11. [PMID: 17095186 DOI: 10.1016/j.reprotox.2006.08.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2004] [Revised: 08/22/2006] [Accepted: 08/22/2006] [Indexed: 11/30/2022]
Abstract
Tributyltin (TBT) is an environmental contaminant commonly used in anti-fouling agents for boats, as well as a by-product from several industrial processes. It has been shown to accumulate in organisms living in areas with heavy maritime traffic thereby entering the food chain. Here, we determined the consequences of in utero exposure to TBT on the developing fetal gonads in the Sprague-Dawley rat. Timed pregnant rats were gavaged either with vehicle or TBT (0.25, 2.5, 10 or 20 mg/kg) from days 0 to 19 or 8 to 19 of gestation. On gestational day 20, dams were sacrificed; fetal testes and ovaries were processed for light (LM) or electron microscopic (EM) evaluation and RNA was prepared for gene expression profiling. At the highest doses of TBT the number of Sertoli cells and gonocytes was reduced, there were large intracellular spaces between Sertoli cells and gonocytes and there was an increased abundance of lipid droplets in the Sertoli cells; EM studies revealed abnormally dilated endoplasmic reticulum in Sertoli cells and gonocytes. In the intertubular region between adjacent interstitial cells, immunostaining for the gap junctional protein connexin 43 was strong in controls, whereas it was reduced or completely absent in treated rats. In the ovaries, TBT (20 mg/kg, days 0-19; 10 mg/kg, days 8-19) reduced the number of germ cells by 44% and 46%, respectively. On examining gene expression profiles in the testis, 40 genes out of 1176 tested were upregulated more than two-fold over control. While no genes were upregulated in the TBT exposed fetal ovary, eight genes were downregulated. In conclusion, in utero exposure to TBT resulted in gender-specific alterations in gonadal development and gene expression profiles suggesting that there may be different adaptive changes to toxicity in developing male and female rats.
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Affiliation(s)
- Osama Kishta
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3G 1Y6, Canada
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Shovlin TC, Bourc'his D, La Salle S, O'Doherty A, Trasler JM, Bestor TH, Walsh CP. Sex-specific promoters regulate Dnmt3L expression in mouse germ cells. Hum Reprod 2006; 22:457-67. [PMID: 17060371 DOI: 10.1093/humrep/del379] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Dnmt3L, a member of the DNA methyltransferase 3 family, lacks enzymatic activity but is required for de-novo methylation of imprinted genes in oocytes and for transposon repression in male germ cells. METHODS We used northern blots, RT-PCR, 5' rapid amplification of complementary DNA (cDNA) ends (RACE), RNase H mapping, real-time/quantitative RT-PCR and in situ hybridization to identify and characterize Dnmt3L transcripts produced during germ cell development. RESULTS Mouse Dnmt3L uses three sex-specific promoters, not the single promoter previously thought. A promoter active in prospermatogonia drives transcription of an mRNA encoding the full-length protein in perinatal testis, where de-novo methylation occurs. Late pachytene spermatocytes activate a second promoter in intron 9 of the Dnmt3L gene. After this stage, the predominant transcripts are three truncated mRNAs, which appear to be non-coding. We could also detect similar adult testis transcripts in humans. In the mouse ovary, an oocyte-specific promoter located in an intron of the neighbouring autoimmune regulator (Aire) gene produces a transcript with the full open reading frame (ORF). This is the only Dnmt3L transcript found in growing oocytes and is absent in the oocytes of Dnmt3L-/- females. CONCLUSIONS Sex-specific promoters control Dnmt3L expression in the mouse germ line, mirroring the situation at the Dnmt1 and Dnmt3A loci.
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Affiliation(s)
- T C Shovlin
- Stem Cells and Epigenetics Research Group, Centre for Molecular Biosciences, School of Biomedical Sciences, University of Ulster, Coleraine, UK
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Oakes CC, La Salle S, Robaire B, Trasler JM. Evaluation of a quantitative DNA methylation analysis technique using methylation-sensitive/dependent restriction enzymes and real-time PCR. Epigenetics 2006; 1:146-52. [PMID: 17965615 DOI: 10.4161/epi.1.3.3392] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
DNA methylation in mammals has been shown to play many important roles in diverse biological phenomena. Several methods have been developed for the measurement of region-specific levels of DNA methylation. We sought a technique that could be used to quantitatively evaluate multiple independent loci in several tissues in a quick and cost-effective manner. Recently, a few quantitative techniques have been developed by employing the use of real-time PCR, though they require the additional step of sodium bisulfite conversion. Here we evaluate a technique that involves the digestion of non-sodium bisulfite-treated genomic DNA using methylation-sensitive and methylation-dependent restriction enzymes followed by real-time PCR. The utility of this method is tested by analyzing seventeen genomic regions of known tissue-specific levels of DNA methylation including three imprinted genes. We find that this approach generates rapid, reproducible and accurate results (range = +/-5%) without the additional time required for bisulfite conversion. This approach is also adaptable for use with smaller amounts of starting material. We propose this method as a rapid, quantitative method for the analysis of DNA methylation at single sites or within small regions of DNA.
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Affiliation(s)
- Christopher C Oakes
- Department of Pharmacology and Therapeutics, The Montreal Children's Hospital Research Institute, McGill University, Montreal, Quebec, Canada
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La Salle S, Trasler JM. Dynamic expression of DNMT3a and DNMT3b isoforms during male germ cell development in the mouse. Dev Biol 2006; 296:71-82. [PMID: 16725135 DOI: 10.1016/j.ydbio.2006.04.436] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Revised: 02/27/2006] [Accepted: 04/04/2006] [Indexed: 11/28/2022]
Abstract
In the male germ line, sequence-specific methylation patterns are initially acquired prenatally in diploid gonocytes and are further consolidated after birth during spermatogenesis. It is still unclear how DNA methyltransferases are involved in establishing and/or maintaining these patterns in germ cells, or how their activity is regulated. We compared the temporal expression patterns of the postulated de novo DNA methyltransferases DNMT3a and DNMT3b in murine male germ cells. Mitotic, meiotic and post-meiotic male germ cells were isolated, and expression of various transcript variants and isoforms of Dnmt3a and Dnmt3b was examined using Quantitative RT-PCR and Western blotting. We found that proliferating and differentiating male germ cells were marked by distinctive expression profiles. Dnmt3a2 and Dnmt3b transcripts were at their highest levels in type A spermatogonia, decreased dramatically in type B spermatogonia and preleptotene spermatocytes and rose again in leptotene/zygotene spermatocytes, while Dnmt3a expression was mostly constant, except in type B spermatogonia where it increased. In all cases, expression declined as pachynema progressed. At the protein level, DNMT3a was the predominant isoform in type B spermatogonia, while DNMT3a2, DNMT3b2, and DNMT3b3 were expressed throughout most of spermatogenesis, except in pachytene spermatocytes. We also detected DNMT3a2 and DNMT3b2 in round spermatids. Taken together, these data highlight the tightly regulated expression of these genes during spermatogenesis and provide evidence that DNMTs may be contributing differentially to the establishment and/or maintenance of methylation patterns in male germ cells.
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Affiliation(s)
- Sophie La Salle
- Department of Pharmacology and Therapeutics, and Montreal Children's Hospital Research Institute, McGill University, Montreal, QC, Canada H3H 1P3
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Lucifero D, Suzuki J, Bordignon V, Martel J, Vigneault C, Therrien J, Filion F, Smith LC, Trasler JM. Bovine SNRPN methylation imprint in oocytes and day 17 in vitro-produced and somatic cell nuclear transfer embryos. Biol Reprod 2006; 75:531-8. [PMID: 16790688 DOI: 10.1095/biolreprod.106.051722] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Findings from recent studies have suggested that the low survival rate of animals derived via somatic cell nuclear transfer (SCNT) may be in part due to epigenetic abnormalities brought about by this procedure. DNA methylation is an epigenetic modification of DNA that is implicated in the regulation of imprinted genes. Genes subject to genomic imprinting are expressed monoallelically in a parent of origin-dependent manner and are important for embryo growth, placental function, and neurobehavioral processes. The vast majority of imprinted genes have been studied in mice and humans. Herein, our objectives were to characterize the bovine SNRPN gene in gametes and to compare its methylation profile in in vivo-produced, in vitro-produced, and SCNT-derived Day 17 elongating embryos. A CpG island within the 5' region of SNRPN was identified and examined using bisulfite sequencing. SNRPN alleles were unmethylated in sperm, methylated in oocytes, and approximately 50% methylated in somatic samples. The examined SNRPN region appeared for the most part to be normally methylated in three in vivo-produced Day 17 embryos and in eight in vitro-produced Day 17 embryos examined, while alleles from Day 17 SCNT embryos were severely hypomethylated in seven of eight embryos. In this study, we showed that the SNRPN methylation profiles previously observed in mouse and human studies are also conserved in cattle. Moreover, SCNT-derived Day 17 elongating embryos were abnormally hypomethylated compared with in vivo-produced and in vitro-produced embryos, which in turn suggests that SCNT may lead to faulty reprogramming or maintenance of methylation imprints at this locus.
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Affiliation(s)
- Diana Lucifero
- McGill University and Montreal Children's Hospital Research Institute, Montreal, Quebec, Canada
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Abstract
The acquisition of genomic DNA methylation patterns, including those important for development, begins in the germ line. In particular, imprinted genes are differentially marked in the developing male and female germ cells to ensure parent-of-origin-specific expression in the offspring. Abnormalities in imprints are associated with perturbations in growth, placental function, neurobehavioural processes and carcinogenesis. Based, for the most part, on data from the well-characterised mouse model, the present review will describe recent studies on the timing and mechanisms underlying the acquisition and maintenance of DNA methylation patterns in gametes and early embryos, as well as the consequences of altering these patterns.
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Affiliation(s)
- Jacquetta M Trasler
- McGill University-Montreal Children's Hospital Research Institute, Montreal, Quebec, Canada.
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Kelly TLJ, Neaga OR, Schwahn BC, Rozen R, Trasler JM. Infertility in 5,10-methylenetetrahydrofolate reductase (MTHFR)-deficient male mice is partially alleviated by lifetime dietary betaine supplementation. Biol Reprod 2004; 72:667-77. [PMID: 15548731 DOI: 10.1095/biolreprod.104.035238] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Metabolism of folate is essential for proper cellular function. Within the folate pathway, methylenetetrahydrofolate reductase (MTHFR) reduces 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a methyl donor for remethylation of homocysteine to methionine, the precursor of S-adenosylmethionine. S-adenosylmethionine is the methyl donor for numerous cellular reactions. In adult male mice, MTHFR levels are highest in the testis; this finding, in conjunction with recent clinical evidence, suggest an important role for MTHFR in spermatogenesis. Indeed, we show here that severe MTHFR deficiency in male mice results in abnormal spermatogenesis and infertility. Maternal oral administration of betaine, an alternative methyl donor, throughout pregnancy and nursing, resulted in improved testicular histology in Mthfr-/- offspring at Postnatal Day 6, but not at 8 mo of age. However, when betaine supplementation was maintained postweaning, testicular histology improved, and sperm numbers and fertility increased significantly. We postulate that the adverse effects of MTHFR deficiency on spermatogenesis, may, in part, be mediated by alterations in the transmethylation pathway and suggest that betaine supplementation may provide a means to bypass MTHFR deficiency and its adverse effects on spermatogenesis by maintaining normal methylation levels within male germ cells.
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Affiliation(s)
- Tamara L J Kelly
- Department of Pediatrics, McGill University and the Montreal Children's Hospital Research Institute, Montreal, Quebec, Canada
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Abstract
beta-Hexosaminidase (Hex) catalyzes the hydrolysis of terminal sugar residues from a number of substrates such as GM2 gangliosides, glycoproteins, glycolipids, and glycosaminoglycans. As an enzyme present in lysosomes of epithelial cells of the adult rat epididymis, it serves to degrade substances endocytosed from the epididymal lumen. In this way, it modifies and creates a luminal environment where sperm can undergo their maturational modifications. In this study, the postnatal developmental pattern of expression of Hex was examined in animals from days 7-56. In addition, the role of testicular factors on Hex expression in the different cell types and regions of the epididymis of adult rats was examined in orchidectomized and efferent duct-ligated rats. Both parameters were examined on Bouin-fixed epididymides in conjunction with light microscope immunocytochemistry. At postnatal day 7, the epithelium of the entire epididymis was unreactive for anti-Hex antibody. By day 21, narrow and clear cells of their respective regions became reactive, whereas basal cells became reactive only by day 29. Principal cells displayed only an occasional reactive lysosome at day 21, several by day 29, and numerous reactive lysosomes by day 39, comparable to the region-specific distribution noted for 90-day-old animals, and at an age when high androgen levels are attained. Thus, postnatal onset of Hex expression varies according to the different cell types of the epididymis, suggesting different regulatory factors. This finding was confirmed from studies employing adult orchidectomized and efferent duct-ligated adult rats. Indeed, in all experimental animals, Hex immunostaining in narrow, clear, and basal cells was intense and comparable to control animals. In contrast, there was a notable absence of lysosomal staining in principal cells at all time points after orchidectomy, which was restored, however, following testosterone replacement. No effect on Hex expression was observed in efferent duct-ligated animals. Taken together, the data suggest that Hex expression in lysosomes of principal cells is regulated by testosterone or one of its metabolites. However, the expression of Hex being independent of testicular factors in narrow, clear, and basal cells of adult animals, but occurring at different time points during postnatal development, suggests that different regulatory factors are responsible for onset of Hex expression in these cell types during development.
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Affiliation(s)
- Louis Hermo
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada.
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La Salle S, Mertineit C, Taketo T, Moens PB, Bestor TH, Trasler JM. Windows for sex-specific methylation marked by DNA methyltransferase expression profiles in mouse germ cells. Dev Biol 2004; 268:403-15. [PMID: 15063176 DOI: 10.1016/j.ydbio.2003.12.031] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2003] [Revised: 12/24/2003] [Accepted: 12/31/2003] [Indexed: 11/18/2022]
Abstract
The acquisition of genomic methylation in the male germ line is initiated prenatally in diploid gonocytes, while DNA methylation in the female germ line is initiated postnatally in growing oocytes. We compared the temporal expression patterns of the DNA methyltransferases, DNMT1, DNMT3a, DNMT3b, and DNMT3l in the male and female germ lines. DNMT1 expression was examined by immunocytochemistry and Northerns with an emphasis on the prenatal period. In the female, there is a gradual down-regulation of DNMT1 protein in prenatal meiotic prophase I oocytes that is not associated with the production of an untranslated transcript, as it is in the male; these results suggest that the mechanism of meiotic down-regulation differs between the sexes. In the male, DNMT1 is unlikely to play a role in the prenatal acquisition of germ line methylation patterns since it is down-regulated in gonocytes between 14.5 and 18.5 days of gestation and is absent at the time of initiation of DNA methylation. To search for candidate DNMTs that could be involved in establishing methylation patterns in both germ lines, real-time RT-PCR was used to simultaneously study the expression profiles of the three DNMT3 enzymes in developing testes and ovaries; DNMT1 expression was included as a control. Expression profiles of DNMT3a and DNMT3l provide support for an interaction of the two enzymes during prenatal germ cell development and de novo methylation in the male. DNMT3l is the predominant DNMT3 enzyme expressed at high levels in the postnatal female germ line at the time of acquisition of DNA methylation patterns. DNMT1 and DNMT3b expression levels peak concomitantly, shortly after birth in the male, consistent with a role in the maintenance of methylation patterns in proliferating spermatogonia. Together, the results provide clues to specific roles for the different DNMT family members in de novo and maintenance methylation in the developing testis and ovary.
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Affiliation(s)
- Sophie La Salle
- Department of Pharmacology and Therapeutics and the Montreal Children's Hospital Research Institute, McGill University, Montreal, QC, Canada H3H 1P3
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Trasler JM. Gamete imprinting: implications for assisted reproductive technologies. J Assist Reprod Genet 2004; 20:483-4. [PMID: 15035546 DOI: 10.1023/b:jarg.0000013647.64239.ad] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Jacquetta M Trasler
- Department of Pediatrics, McGill University and Montreal Children's Hospital Research Institute, Quebec, Canada
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Abstract
Epigenetics refers to covalent modifications of DNA and core histones that regulate gene activity without altering DNA sequence. To date, the best-characterized DNA modification associated with the modulation of gene activity is methylation of cytosine residues within CpG dinucleotides. Human disorders associated with epigenetic abnormalities include rare imprinting diseases, molar pregnancies, and childhood cancers. Germ cell development and early embryo development are critical times when epigenetic patterns are initiated or maintained. This review focuses on the epigenetic modification DNA methylation and discusses recent progress that has been made in understanding when and how epigenetic patterns are differentially established in the male and female germlines, the mouse, and human disorders associated with abnormalities in epigenetic programming in germ cells and early embryos, as well as genetic and other modulators (e.g. nutrition and drugs) of reproductive epigenetic events.
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Affiliation(s)
- T L J Kelly
- McGill University-Montreal Children's Hospital Research Institute and Department of Paediatrics, McGill University, Montreal, Quebec, Canada
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