1
|
Horakova A, Konecna M, Anger M. Chromosome Division in Early Embryos-Is Everything under Control? And Is the Cell Size Important? Int J Mol Sci 2024; 25:2101. [PMID: 38396778 PMCID: PMC10889803 DOI: 10.3390/ijms25042101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
Chromosome segregation in female germ cells and early embryonic blastomeres is known to be highly prone to errors. The resulting aneuploidy is therefore the most frequent cause of termination of early development and embryo loss in mammals. And in specific cases, when the aneuploidy is actually compatible with embryonic and fetal development, it leads to severe developmental disorders. The main surveillance mechanism, which is essential for the fidelity of chromosome segregation, is the Spindle Assembly Checkpoint (SAC). And although all eukaryotic cells carry genes required for SAC, it is not clear whether this pathway is active in all cell types, including blastomeres of early embryos. In this review, we will summarize and discuss the recent progress in our understanding of the mechanisms controlling chromosome segregation and how they might work in embryos and mammalian embryos in particular. Our conclusion from the current literature is that the early mammalian embryos show limited capabilities to react to chromosome segregation defects, which might, at least partially, explain the widespread problem of aneuploidy during the early development in mammals.
Collapse
Affiliation(s)
- Adela Horakova
- Department of Genetics and Reproductive Biotechnologies, Veterinary Research Institute, 621 00 Brno, Czech Republic
- Institute of Animal Physiology and Genetics, Czech Academy of Science, 277 21 Libechov, Czech Republic
- Faculty of Science, Masaryk University, 602 00 Brno, Czech Republic
| | - Marketa Konecna
- Department of Genetics and Reproductive Biotechnologies, Veterinary Research Institute, 621 00 Brno, Czech Republic
- Institute of Animal Physiology and Genetics, Czech Academy of Science, 277 21 Libechov, Czech Republic
- Faculty of Science, Masaryk University, 602 00 Brno, Czech Republic
| | - Martin Anger
- Department of Genetics and Reproductive Biotechnologies, Veterinary Research Institute, 621 00 Brno, Czech Republic
- Institute of Animal Physiology and Genetics, Czech Academy of Science, 277 21 Libechov, Czech Republic
| |
Collapse
|
2
|
Nandi S, Tripathi SK, Singh PK, Gupta PSP, Mondal S. Global DNA methylation, DNA methyltransferase and stress-related gene expression in ovine oocytes and embryos after exposure to metabolic stressors. Reprod Domest Anim 2023. [PMID: 36920043 DOI: 10.1111/rda.14341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/20/2023] [Accepted: 03/09/2023] [Indexed: 03/16/2023]
Abstract
DNA methylation, considered the most prominent epigenetic mark was important for the gene regulation in embryonic development. The present study aimed at evaluating the effects of metabolic stressors [Non-esterified fatty acid (NEFA), β-hydroxy-butyric acid (BHB), ammonia and urea] exposure during the in vitro ovine oocyte maturation, global DNA methylation, DNA methyltransferase and stress-related gene expression. Colorimetric analysis of global DNA methylation and the expression of the DNA methyltransferase genes (DNMT1, DNMT3A, and DNMT3B) were assessed in the matured oocytes, 2-cell embryos and blastocysts produced in vitro from oocytes exposed with the metabolic stressors during 24 h of the in vitro maturation (IVM). Further, the mRNA expression of the stress-related genes (SOD1, SOD2) in the matured oocytes, 2-cell embryos and blastocysts produced was assessed. Significant difference in global DNA methylation levels between all the treatments tested was observed when compared with control in oocytes, two-cell embryos and blastocysts. Elevated concentration of metabolic stressors resulted in increased expressions of several stress-related genes, i.e., SOD1, SOD2 and in mRNA expression of DNA methyltransferase genes. The present study is the first to report that the DNA methylation was sensitive to the effects of the metabolic stressors in ovine oocytes/embryos. The aberrant expressions of genes during oocyte development targeted in the present study can provide evidence for the early embryo developmental arrest and blastocysts quality. These results highlighted the sensitivity of the early embryogenesis and more precisely of the reprogramming period to metabolites challenges, in a realistic situation of elevated concentration of metabolic stressors.
Collapse
Affiliation(s)
- Sumanta Nandi
- Animal Biotechnology Laboratory, ICAR-National Institute of Animal Nutrition and Physiology, Bangalore, 560030, India
| | - Shiv K Tripathi
- Animal Biotechnology Laboratory, ICAR-National Institute of Animal Nutrition and Physiology, Bangalore, 560030, India
| | - Poonam K Singh
- Animal Biotechnology Laboratory, ICAR-National Institute of Animal Nutrition and Physiology, Bangalore, 560030, India
| | - Paluru S P Gupta
- Animal Biotechnology Laboratory, ICAR-National Institute of Animal Nutrition and Physiology, Bangalore, 560030, India
| | - Sukanta Mondal
- Animal Biotechnology Laboratory, ICAR-National Institute of Animal Nutrition and Physiology, Bangalore, 560030, India
| |
Collapse
|
3
|
Nagai H, Okada M, Nagai Y, Sakuraba Y, Okae H, Suzuki R, Sugimura S. Abnormal cleavage is involved in the self-correction of bovine preimplantation embryos. Biochem Biophys Res Commun 2021; 562:76-82. [PMID: 34044324 DOI: 10.1016/j.bbrc.2021.05.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 05/09/2021] [Indexed: 10/21/2022]
Abstract
Chromosome instability leading to aneuploidy during early cleavage is well known in humans and cattle. Partial compaction (PC), which occurs only in some blastomeres, is suggested as a self-correction mechanism through which human embryos avoid aneuploid mosaicism. Partially compacted embryos show abnormal cleavages more frequently during early development; however, the mechanism by which blastomeres are excluded has not been elucidated. Here, we confirmed PC in approximately half of the tested bovine embryos, similar to that in human embryos. DNA sequencing of single-cell and intact embryos revealed that the morulae that excluded some blastomeres had euploidy, but many of the excluded blastomeres had aneuploidy. Time-lapse imaging of zygotes without the zona pellucida revealed that the excluded blastomeres underwent reverse and direct cleavages, which are abnormal cleavages, more frequently than the blastomeres involved in compaction. These results suggest the potential role of abnormal cleavage in the self-correction mechanism during the development of mammalian preimplantation embryos.
Collapse
Affiliation(s)
- Hiroki Nagai
- Department of Biological Production, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Mai Okada
- Department of Biological Production, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | | | | | - Hiroaki Okae
- Department of Informative Genetics, Environment and Genome Research Center, Graduate School of Medicine, Tohoku University, Miyagi 980-8575, Japan
| | - Ryosuke Suzuki
- Department of Biological Production, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan; Kanagawa Ladies Clinic, Kanagawa, 221-0822, Japan
| | - Satoshi Sugimura
- Department of Biological Production, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan.
| |
Collapse
|
4
|
Anesetti G, Chávez-Genaro R. Neonatal androgenization in rats affects oocyte maturation. Reprod Sci 2021; 28:2799-2806. [PMID: 33825168 DOI: 10.1007/s43032-021-00559-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 03/25/2021] [Indexed: 10/21/2022]
Abstract
Androgens are relevant in order to achieve a normal growth and maturation of the follicle and oocyte, since both excess and absence of androgens may affect the correct ovarian function. The current study analyzes the impact of neonatal androgenization in the first ovulation and oocyte maturation in response to exogenous gonadotrophin stimulation. Neonatal rats were daily treated with testosterone, dihydrotestosterone, or vehicle during follicle assembly period (days 1 to 5). At juvenile period, rats were stimulated sequentially with PMSG and hCG. Ovulation, ovarian histology, hormonal milieu, morphological characteristics of meiotic spindle, and in vitro fertilization rate in oocytes were analyzed. Our data shows that oocytes from androgenized rats displayed a major proportion of aberrant spindles and altered meiotic advance that control animals. These alterations were accompanied with an increase in both fertilization rate and aberrant embryos after 48 h of culture. Our findings showed a direct impact of neonatal androgens on oocyte development; their effects may be recognized at adulthood, supporting the idea of a programming effect exerted by neonatal androgens. These results could be relevant to explain the low fertility rate seen in polycystic ovary syndrome patients after in vitro fertilization procedures.
Collapse
Affiliation(s)
- Gabriel Anesetti
- Laboratorio de Biología de la Reproducción, Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
| | - Rebeca Chávez-Genaro
- Laboratorio de Biología de la Reproducción, Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| |
Collapse
|
5
|
Christodoulaki A, Boel A, Tang M, De Roo C, Stoop D, Heindryckx B. Prospects of Germline Nuclear Transfer in Women With Diminished Ovarian Reserve. Front Endocrinol (Lausanne) 2021; 12:635370. [PMID: 33692760 PMCID: PMC7937897 DOI: 10.3389/fendo.2021.635370] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/06/2021] [Indexed: 12/12/2022] Open
Abstract
Diminished ovarian reserve (DOR) is associated with a reduced quantity and quality of the retrieved oocytes, usually leading to poor reproductive outcomes which remain a great challenge for assisted reproduction technology (ART). Women with DOR often have to seek for oocyte donation, precluding genetically related offspring. Germline nuclear transfer (NT) is a novel technology in ART that involves the transfer of the nuclear genome from an affected oocyte/zygote of the patient to the cytoplast of an enucleated donor oocyte/zygote. Therefore, it offers opportunities for the generation of genetically related embryos. Currently, although NT is clinically applied only in women with serious mitochondrial DNA disorders, this technology has also been proposed to overcome certain forms of female infertility, such as advanced maternal age and embryo developmental arrest. In this review, we are proposing the NT technology as a future treatment option for DOR patients. Strikingly, the application of different NT strategies will result in an increase of the total number of available reconstituted embryos for DOR patients.
Collapse
Affiliation(s)
- Antonia Christodoulaki
- Ghent-Fertility and Stem cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | - Annekatrien Boel
- Ghent-Fertility and Stem cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | - Maoxing Tang
- Ghent-Fertility and Stem cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
- Reproductive Medicine Center, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Chloë De Roo
- Ghent-Fertility and Stem cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | - Dominic Stoop
- Ghent-Fertility and Stem cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | - Björn Heindryckx
- Ghent-Fertility and Stem cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| |
Collapse
|
6
|
Martin JH, Aitken RJ, Bromfield EG, Nixon B. DNA damage and repair in the female germline: contributions to ART. Hum Reprod Update 2020; 25:180-201. [PMID: 30541031 DOI: 10.1093/humupd/dmy040] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/27/2018] [Accepted: 11/06/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND DNA integrity and stability are critical determinants of cell viability. This is especially true in the female germline, wherein DNA integrity underpins successful conception, embryonic development, pregnancy and the production of healthy offspring. However, DNA is not inert; rather, it is subject to assault from various environment factors resulting in chemical modification and/or strand breakage. If structural alterations result and are left unrepaired, they have the potential to cause mutations and propagate disease. In this regard, reduced genetic integrity of the female germline ranks among the leading causes of subfertility in humans. With an estimated 10% of couples in developed countries taking recourse to ART to achieve pregnancy, the need for ongoing research into the capacity of the oocyte to detect DNA damage and thereafter initiate cell cycle arrest, apoptosis or DNA repair is increasingly more pressing. OBJECTIVE AND RATIONALE This review documents our current knowledge of the quality control mechanisms utilised by the female germline to prevent and remediate DNA damage during their development from primordial follicles through to the formation of preimplantation embryos. SEARCH METHODS The PubMed database was searched using the keywords: primordial follicle, primary follicle, secondary follicle, tertiary follicle, germinal vesical, MI, MII oocyte, zygote, preimplantation embryo, DNA repair, double-strand break and DNA damage. These keywords were combined with other phrases relevant to the topic. Literature was restricted to peer-reviewed original articles in the English language (published 1979-2018) and references within these articles were also searched. OUTCOMES In this review, we explore the quality control mechanisms utilised by the female germline to prevent, detect and remediate DNA damage. We follow the trajectory of development from the primordial follicle stage through to the preimplantation embryo, highlighting findings likely to have important implications for fertility management, age-related subfertility and premature ovarian failure. In addition, we survey the latest discoveries regarding DNA repair within the metaphase II (MII) oocyte and implicate maternal stores of endogenous DNA repair proteins and mRNA transcripts as a primary means by which they defend their genomic integrity. The collective evidence reviewed herein demonstrates that the MII oocyte can engage in the activation of major DNA damage repair pathway(s), therefore encouraging a reappraisal of the long-held paradigm that oocytes are largely refractory to DNA repair upon reaching this late stage of their development. It is also demonstrated that the zygote can exploit a number of protective strategies to mitigate the risk and/or effect the repair, of DNA damage sustained to either parental germline; affirming that DNA protection is largely a maternally driven trait but that some aspects of repair may rely on a collaborative effort between the male and female germlines. WIDER IMPLICATIONS The present review highlights the vulnerability of the oocyte to DNA damage and presents a number of opportunities for research to bolster the stringency of the oocyte's endogenous defences, with implications extending to improved diagnostics and novel therapeutic applications to alleviate the burden of infertility.
Collapse
Affiliation(s)
- Jacinta H Martin
- Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, Kookaburra Circuit, New Lambton Heights, NSW, Australia
| | - R John Aitken
- Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, Kookaburra Circuit, New Lambton Heights, NSW, Australia
| | - Elizabeth G Bromfield
- Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, Kookaburra Circuit, New Lambton Heights, NSW, Australia
| | - Brett Nixon
- Priority Research Centre for Reproductive Science, Discipline of Biological Sciences, University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, Kookaburra Circuit, New Lambton Heights, NSW, Australia
| |
Collapse
|
7
|
Laisk T, Tšuiko O, Jatsenko T, Hõrak P, Otala M, Lahdenperä M, Lummaa V, Tuuri T, Salumets A, Tapanainen JS. Demographic and evolutionary trends in ovarian function and aging. Hum Reprod Update 2020; 25:34-50. [PMID: 30346539 DOI: 10.1093/humupd/dmy031] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 09/03/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The human female reproductive lifespan is regulated by the dynamics of ovarian function, which in turn is influenced by several factors: from the basic molecular biological mechanisms governing folliculogenesis, to environmental and lifestyle factors affecting the ovarian reserve between conception and menopause. From a broader point of view, global and regional demographic trends play an additional important role in shaping the female reproductive lifespan, and finally, influences on an evolutionary scale have led to the reproductive senescence that precedes somatic senescence in humans. OBJECTIVE AND RATIONALE The narrative review covers reproductive medicine, by integrating the molecular mechanisms of ovarian function and aging with short-term demographic and long-term evolutionary trends. SEARCH METHODS PubMed and Google Scholar searches were performed with relevant keywords (menopause, folliculogenesis, reproductive aging, reproductive lifespan and life history theory). The reviewed articles and their references were restricted to those written in English. OUTCOMES We discuss and summarize the rapidly accumulating information from large-scale population-based and single-reproductive-cell genomic studies, their constraints and advantages in the context of female reproductive aging as well as their possible evolutionary significance on the life history trajectory from foetal-stage folliculogenesis until cessation of ovarian function in menopause. The relevant environmental and lifestyle factors and demographic trends are also discussed in the framework of predominant evolutionary hypotheses explaining the origin and maintenance of menopause. WIDER IMPLICATIONS The high speed at which new data are generated has so far raised more questions than it has provided solid answers and has been paralleled by a lack of satisfactory interpretations of the findings in the context of human life history theory. Therefore, the recent flood of data could offer an unprecedented tool for future research to possibly confirm or rewrite human evolutionary reproductive history, at the same time providing novel grounds for patient counselling and family planning strategies.
Collapse
Affiliation(s)
- Triin Laisk
- Competence Centre on Health Technologies, Tiigi 61b, Tartu, Estonia.,Institute of Clinical Medicine, Department of Obstetrics and Gynaecology, University of Tartu, L. Puusepa 8, Tartu, Estonia
| | - Olga Tšuiko
- Competence Centre on Health Technologies, Tiigi 61b, Tartu, Estonia.,Institute of Biomedicine and Translational Medicine, Department of Biomedicine, University of Tartu, Ravila 19, Tartu, Estonia
| | - Tatjana Jatsenko
- Competence Centre on Health Technologies, Tiigi 61b, Tartu, Estonia
| | - Peeter Hõrak
- Department of Zoology, University of Tartu, Vanemuise 46, Tartu, Estonia
| | - Marjut Otala
- Department of Obstetrics and Gynecology, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 2, Helsinki, Finland
| | - Mirkka Lahdenperä
- Department of Biology, University of Turku, Turun yliopisto, Turku, Finland
| | - Virpi Lummaa
- Department of Biology, University of Turku, Turun yliopisto, Turku, Finland
| | - Timo Tuuri
- Department of Obstetrics and Gynecology, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 2, Helsinki, Finland
| | - Andres Salumets
- Competence Centre on Health Technologies, Tiigi 61b, Tartu, Estonia.,Institute of Clinical Medicine, Department of Obstetrics and Gynaecology, University of Tartu, L. Puusepa 8, Tartu, Estonia.,Institute of Biomedicine and Translational Medicine, Department of Biomedicine, University of Tartu, Ravila 19, Tartu, Estonia.,Department of Obstetrics and Gynecology, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 2, Helsinki, Finland
| | - Juha S Tapanainen
- Department of Obstetrics and Gynecology, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 2, Helsinki, Finland.,Department of Obstetrics and Gynecology, University Hospital of Oulu, University of Oulu, Medical Research Center Oulu and PEDEGO Research Unit, OYS Oulu, Finland
| |
Collapse
|
8
|
Han J, Chen M, Fang Q, Zhang Y, Wang Y, Esma J, Qiao H. Prediction of the Prognosis Based on Chromosomal Instability-Related DNA Methylation Patterns of ELOVL2 and UBAC2 in PTCs. MOLECULAR THERAPY. NUCLEIC ACIDS 2019; 18:650-660. [PMID: 31698312 PMCID: PMC6906861 DOI: 10.1016/j.omtn.2019.09.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 08/12/2019] [Accepted: 09/17/2019] [Indexed: 12/11/2022]
Abstract
Papillary thyroid carcinoma (PTC) is the most common malignant tumor of endocrine systems. Chromosomal instability (CIN) is crucial to the clinical prognoses of tumor patients. DNA methylation plays an important role in the regulation of gene expression and CIN. Based on PTC samples from The Cancer Genome Atlas database, we used multiple regression analyses to identify methylation patterns of CpG sites with the strongest correlation with gene expression. A total of 4,997 genes were obtained through combining the CpG sites, which were represented as featured DNA methylation patterns. In order to identify CIN-related epigenetic markers of PTC survival, we developed a method to characterize CIN based on DNA methylation patterns of genes using the Student’s t statistics. We found that 1,239 genes were highly associated with CIN. With the use of the log-rank test, univariate Cox regression analyses, and the Kaplan-Meier method, DNA methylation patterns of UBAC2 and ELOVL2, highly correlated with CIN, provided potential prognostic values for PTC. The higher these two genes, risk scores were correlated with worse PTC patient prognoses. Moreover, the ELOVL2 risk score was significantly different in the four stages of PTC, suggesting that it was related to the progress of PTC. The DNA methylation pattern associated with CIN may therefore be a good predictor of PTC survival.
Collapse
Affiliation(s)
- Jun Han
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Harbin Medical University, The Fourth Affiliated Hospital, Harbin Medical University, Harbin 150001, China
| | - Meijun Chen
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Harbin Medical University, Harbin 150001, China
| | - Qingxiao Fang
- Surgical Oncology, The Second Affiliated Hospital, Harbin Medical University, Harbin 150001, China
| | - Yanqing Zhang
- Hematological Department, The Second Affiliated Hospital, Harbin Medical University, Harbin 150001, China
| | - Yihan Wang
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin 150001, China
| | - Jamaspishvili Esma
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Harbin Medical University, Harbin 150001, China
| | - Hong Qiao
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Harbin Medical University, Harbin 150001, China.
| |
Collapse
|
9
|
Escribà MJ, Vendrell X, Peinado V. Segmental aneuploidy in human blastocysts: a qualitative and quantitative overview. Reprod Biol Endocrinol 2019; 17:76. [PMID: 31526391 PMCID: PMC6745804 DOI: 10.1186/s12958-019-0515-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/19/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Microarray-based and next generation sequencing (NGS) technologies have revealed that segmental aneuploidy is frequently present in human oocytes, cleavage-stage embryos and blastocysts. However, very little research has analyzed the type, size, chromosomal distribution and topography of the chromosomal segments at the different stages of development. METHODS This is a retrospective study of 822 PGT-A (preimplantation genetic test for aneuploidies) performed on trophectoderm samples from 3565 blastocysts biopsied between January 2016 and April 2017. The cycles in question had been initiated for varying clinical indications. Samples were analyzed by next generation sequencing-based technology. Segmental aneuploidies were evaluated when fragment size was > 5 Mb. Blastocysts presenting a single segmental aneuploidy (SSA), without any additional whole-chromosome gain/loss, were statistically analyzed for incidence, type, size and chromosomal emplacement. Segment sizes relative to the whole chromosome or arm (chromosome- and arm-ratios) were also studied. RESULTS 8.4% (299/3565) of blastocysts exhibited segmental aneuploidy for one or more chromosomes, some of which were associated with whole-chromosome aneuploidy while others were not. Nearly half of them (4.5%: 159/3565 of blastocysts) exhibited pure-SSA, meaning that a single chromosome was affected by a SSA. Segments were more frequent in medium-sized metacentric or submetacentric chromosomes and particularly in q-chrmosome arms, variables that were related to trophectoderm quality. SSA size was related to a greater extent to chromosome number and the arm affected than it was to SSA type. In absolute values (Mb), SSA size was larger in large chromosomes. However, the SSA:chromosome ratio was constant across all chromosomes and never exceeded 50% of the chromosome. CONCLUSIONS SSA frequency is chromosome- and topographically dependent, and its incidence is not related to clinical or embryological factors, but rather to trophectoderm quality. SSA might be originated by chromosome instability in response to chromothripsis, bias introduced by the biopsy and/or iatrogenic effects. TRIAL REGISTRATION Retrospectively registered.
Collapse
Affiliation(s)
| | - Xavier Vendrell
- Reproductive Genetics Unit, Sistemas Genómicos, Parque Tecnológico Paterna, 46980, Valencia, Spain
| | - Vanessa Peinado
- Igenomix, Parque Tecnológico Paterna, 46980, Valencia, Spain
| |
Collapse
|
10
|
|
11
|
Abstract
Life starts with a zygote, which is formed by the fusion of a haploid sperm and egg. The formation of a blastomere by cleavage division (nuclear division without an increase in cell size) is the first step in embryogenesis, after the formation of the zygote. Blastomeres are responsible for reprogramming the parental genome as a new embryonic genome for generation of the pluripotent stem cells which then differentiate by Waddington's epigenetic landscape to create a new life. Multiple authors over the past 150 years have proposed that tumors arises from development gone awry at a point within Waddington's landscape. Recent discoveries showing that differentiated somatic cells can be reprogrammed into induced pluripotent stem cells, and that somatic cell nuclear transfer can be used to successfully clone animals, have fundamentally reshaped our understanding of tumor development and origin. Differentiated somatic cells are plastic and can be induced to dedifferentiate into pluripotent stem cells. Here, I review the evidence that suggests somatic cells may have a previously overlooked endogenous embryonic program that can be activated to dedifferentiate somatic cells into stem cells of various potencies for tumor initiation. Polyploid giant cancer cells (PGCCs) have long been observed in cancer and were thought originally to be nondividing. Contrary to this belief, recent findings show that stress-induced PGCCs divide by endoreplication, which may recapitulate the pattern of cleavage-like division in blastomeres and lead to dedifferentiation of somatic cells by a programmed process known as "the giant cell cycle", which comprise four distinct but overlapping phases: initiation, self-renewal, termination and stability. Depending on the intensity and type of stress, different levels of dedifferentiation result in the formation of tumors of different grades of malignancy. Based on these results, I propose a unified dualistic model to demonstrate the origin of human tumors. The tenet of this model includes four points, as follows. 1. Tumors originate from a stem cell at a specific developmental hierarchy, which can be achieved by dualistic origin: dedifferentiation of the zygote formed by two haploid gametes (sexual reproduction) via the blastomere during normal development, or transformation from damaged or aged mature somatic cells via a blastomere-like embryonic program (asexual reproduction). 2. Initiation of the tumor begins with a stem cell that has uncoupled the differentiation from the proliferation program which results in stem cell maturation arrest. 3. The developmental hierarchy at which stem cells arrest determines the degree of malignancy: the more primitive the level at which stem cells arrest, the greater the likelihood of the tumor being malignant. 4. Environmental factors and intrinsic genetic or epigenetic alterations represent the risk factors or stressors that facilitate stem cell arrest and somatic cell dedifferentiation. However, they, per se, are not the driving force of tumorigenesis. Thus, the birth of a tumor can be viewed as a triad that originates from a stem cell via dedifferentiation through a blastomere or blastomere-like program, which then differentiates along Waddington's landscape, and arrests at a developmental hierarchy. Blocking the PGCC-mediated dedifferentiation process and inducing their differentiation may represent a novel alternative approach to eliminate the tumor occurrence and therapeutic resistance.
Collapse
|
12
|
Yu L, Jia C, Lan Y, Song R, Zhou L, Li Y, Liang Y, Wang S. Analysis of embryo intactness and developmental potential following slow freezing and vitrification. Syst Biol Reprod Med 2017; 63:285-293. [PMID: 28795845 DOI: 10.1080/19396368.2017.1362060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The aim of this study was to identify the parameters that are related to intactness and developmental potential of a day 3 embryo after warming to improve the selection criteria used to cryopreserve and transfer embryos. We also sought to compare slow freezing and vitrification methods of cryopreservation and to evaluate the viability of non-intact embryos. Embryos warmed following slow freezing (n=220) or vitrification (n=522) were divided into 3 groups according to the proportion of surviving blastomeres (I<50%; II=50-99%; and III=100%). The developmental potential of embryos, including the mitosis resumption rate, blastocyst formation rate, and formation rate of grade A blastocysts (i.e., fully expanded blastocysts with an inner cell mass and grade A or B trophectoderm) were retrospectively assessed in embryos. Cleavage-stage embryos with <50% blastomere survival were analyzed using next-generation sequencing (NGS). Logistic regression analysis showed that vitrification and grade 1 were independent predictive factors of embryo intactness and developmental potential (all p<0.05). On day 3, embryos with 4-6 cells or blastomere damage had lower developmental potential than those with 7-9 cells or intact blastomeres (all p<0.05). NGS results showed that the chromosomal status was completely normal in 8 embryos that developed into expanded blastocysts, whereas 4 out of 5 embryos in which development was arrested were abnormal. The results of this study suggest that vitrification is a better choice than slow freezing for embryo cryopreservation. Embryos showing poor quality (fragmentation >30% and/or a non-stage-specific cell size) and lower cell numbers (4-6 cells) on day 3 should be cultured to the blastocyst stage and then vitrified if they develop into good-quality blastocysts. The developmental potential of non-intact embryos is lower than that of intact embryos; however, after they are cultured to the fully expanded blastocyst stage, embryos with <50% blastomere survival appear to be better candidates for transfer. Abbreviations ART: assisted reproductive technology; grade A blastocyst: fully expanded blastocyst with an inner cell mass and grade A or B trophectoderm; NGS: next-generation sequencing; IVF: in vitro fertilization; ICSI: intracytoplasmic sperm injection; FET: frozen-thawed embryo transfer.
Collapse
Affiliation(s)
- Lan Yu
- a Department of Reproductive Medicine , Beijing Obstetrics and Gynecology Hospital, Capital Medical University , Beijing , China
| | - Chanwei Jia
- a Department of Reproductive Medicine , Beijing Obstetrics and Gynecology Hospital, Capital Medical University , Beijing , China
| | - Yonglian Lan
- a Department of Reproductive Medicine , Beijing Obstetrics and Gynecology Hospital, Capital Medical University , Beijing , China
| | - Rui Song
- a Department of Reproductive Medicine , Beijing Obstetrics and Gynecology Hospital, Capital Medical University , Beijing , China
| | - Liying Zhou
- a Department of Reproductive Medicine , Beijing Obstetrics and Gynecology Hospital, Capital Medical University , Beijing , China
| | - Ying Li
- a Department of Reproductive Medicine , Beijing Obstetrics and Gynecology Hospital, Capital Medical University , Beijing , China
| | - Yu Liang
- a Department of Reproductive Medicine , Beijing Obstetrics and Gynecology Hospital, Capital Medical University , Beijing , China
| | - Shuyu Wang
- a Department of Reproductive Medicine , Beijing Obstetrics and Gynecology Hospital, Capital Medical University , Beijing , China
| |
Collapse
|
13
|
Rosenkrantz JL, Carbone L. Investigating somatic aneuploidy in the brain: why we need a new model. Chromosoma 2017; 126:337-350. [PMID: 27638401 PMCID: PMC5908214 DOI: 10.1007/s00412-016-0615-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 08/18/2016] [Accepted: 08/22/2016] [Indexed: 12/17/2022]
Abstract
The steady occurrence of DNA mutations is a key source for evolution, generating the genomic variation in the population upon which natural selection acts. Mutations driving evolution have to occur in the oocytes and sperm in order to be transmitted to the next generation. Through similar mechanisms, mutations also accumulate in somatic cells (e.g., skin cells, neurons, lymphocytes) during development and adult life. The concept that somatic cells can collect new mutations with time suggests that we are a mosaic of cells with different genomic compositions. Particular attention has been recently paid to somatic mutations in the brain, with a focus on the relationship between this phenomenon and the origin of human diseases. Given this progressive accumulation of mutations, it is likely that an increased load of somatic mutations is present later in life and that this could be associated with late-life diseases and aging. In this review, we focus on a particular type of mutation: the loss and/or gain of whole chromosomes (i.e., aneuploidy) caused by errors in chromosomes segregation in neurons and glia. Currently, it is hard to grasp the functional impact of somatic mutation in the brain because we lack reliable estimates of the proportion of aneuploid cells in the normal brain across different ages. Here, we revisit the key studies that attempted to quantify the proportion of aneuploid cells in both normal and diseased brains and highlight the deep inconsistencies among the different studies done in the last 15 years. Finally, our review highlights several limitations of studies performed in human and rodent models and explores a possible translational role for non-human primates.
Collapse
Affiliation(s)
- Jimi L Rosenkrantz
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA
| | - Lucia Carbone
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA.
- Department of Medicine, Oregon Health and Science University, Portland, OR, USA.
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA.
- Division of Neuroscience, Primate Genetics Section, Oregon National Primate Research Center, Beaverton, OR, USA.
| |
Collapse
|
14
|
McCoy RC. Mosaicism in Preimplantation Human Embryos: When Chromosomal Abnormalities Are the Norm. Trends Genet 2017; 33:448-463. [PMID: 28457629 DOI: 10.1016/j.tig.2017.04.001] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/31/2017] [Accepted: 04/03/2017] [Indexed: 11/15/2022]
Abstract
Along with errors in meiosis, mitotic errors during post-zygotic cell division contribute to pervasive aneuploidy in human embryos. Relatively little is known, however, about the genesis of these errors or their fitness consequences. Rapid technological advances are helping to close this gap, revealing diverse molecular mechanisms contributing to mitotic error. These include altered cell cycle checkpoints, aberrations of the centrosome, and failed chromatid cohesion, mirroring findings from cancer biology. Recent studies are challenging the idea that mitotic error is abnormal, emphasizing that the fitness impacts of mosaicism depend on its scope and severity. In light of these findings, technical and philosophical limitations of various screening approaches are discussed, along with avenues for future research.
Collapse
Affiliation(s)
- Rajiv C McCoy
- Department of Genome Sciences, University of Washington, Seattle, WA, USA.
| |
Collapse
|
15
|
Capalbo A, Rienzi L. Mosaicism between trophectoderm and inner cell mass. Fertil Steril 2017; 107:1098-1106. [PMID: 28433375 DOI: 10.1016/j.fertnstert.2017.03.023] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 03/21/2017] [Indexed: 11/28/2022]
Abstract
Defining the actual incidence and prevalence of mosaicism in human blastocysts still remains a difficult task. The small amount of evidence generated by animal and human studies does not support the existence of mechanisms involved in developmental arrest, clonal depletion, or aneuploidy rescue for abnormal cells in euploid/aneuploid embryos during preimplantation development. However, studies in humans are mainly descriptive and lack functional evidence. Understanding the biological mechanisms that beset preimplantation differentiation holds the potential to reveal the role of aneuploidies and gene dosage imbalances in cell fate decision, providing important clues on the origin and evolution of embryonic mosaicism. The evidence on human blastocysts suggests that a mosaic euploid/aneuploid configuration is detected in around 5% of embryos. This figure supports the extremely low level of mosaicism reported in natural and IVF pregnancies. Similarly, the clinical management of patterns consistent with the presence of mosaicism in a trophectoderm biopsy during preimplantation genetic diagnosis cycles (PGD-A) is still a controversial issue. Despite the facts that some contemporary comprehensive chromosomal screening platforms can detect mosaic samples in cell mixture models with variable accuracy and many reproductive genetics laboratories are now routinely including embryonic mosaicism on their genetic reports, a diagnosis of certainty for mosaicism in PGD-A cycles is conceptually impracticable. Indeed, several technical and biological sources of errors clearly exist when trying to estimate mosaicism from a single trophectoderm biopsy in PGD-A cycles and must be understood to adequately guide patients during clinical care.
Collapse
Affiliation(s)
- Antonio Capalbo
- GENERA, Centre for Reproductive Medicine, Clinica Valle Giulia, Rome, Italy; GENETYX, Molecular Genetics Laboratory, Vicenza, Italy.
| | - Laura Rienzi
- GENERA, Centre for Reproductive Medicine, Clinica Valle Giulia, Rome, Italy; GENETYX, Molecular Genetics Laboratory, Vicenza, Italy
| |
Collapse
|
16
|
Early human embryos are naturally aneuploid-can that be corrected? J Assist Reprod Genet 2016; 34:15-21. [PMID: 27900612 PMCID: PMC5330987 DOI: 10.1007/s10815-016-0845-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 11/14/2016] [Indexed: 11/16/2022] Open
Abstract
Aneuploidy is common and may be a natural occurrence in early human embryos. Selecting against embryos containing aneuploid cells for embryo transfer has been reported to increase clinical pregnancies per transfer in some studies, but not others. Some aneuploidy is due to misallocation of chromosomes during meiosis, in either the egg or sperm, but most aneuploidy is due to misallocation of chromosomes during mitoses after fertilization. Big questions are as follows: Why does this happen? How much aneuploidy in a preimplantation embryo is compatible with normal fetal development? Is aneuploidy increased by in vitro culture, and/or could it be prevented or corrected in the IVF lab?
Collapse
|
17
|
Velazquez MA, Smith CGC, Smyth NR, Osmond C, Fleming TP. Advanced maternal age causes adverse programming of mouse blastocysts leading to altered growth and impaired cardiometabolic health in post-natal life. Hum Reprod 2016; 31:1970-80. [PMID: 27402911 PMCID: PMC4991661 DOI: 10.1093/humrep/dew177] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 06/17/2016] [Indexed: 12/27/2022] Open
Abstract
STUDY QUESTION Does advanced maternal age (AMA) in mice affect cardiometabolic health during post-natal life in offspring derived from an assisted reproduction technology (ART) procedure? SUMMARY ANSWER Offspring derived from blastocysts collected from aged female mice displayed impaired body weight gain, blood pressure, glucose metabolism and organ allometry during post-natal life compared with offspring derived from blastocysts from young females; since all blastocysts were transferred to normalized young mothers, this effect is independent of maternal pregnancy conditions. WHAT IS KNOWN ALREADY Although studies in mice have shown that AMA can affect body weight and behaviour of offspring derived from natural reproduction, data on the effects of AMA on offspring cardiometabolic health during post-natal development are not available. Given the increasing use of ART to alleviate infertility in women of AMA, it is pivotal to develop ART-AMA models addressing the effects of maternal aging on offspring health. STUDY DESIGN, SIZE, DURATION Blastocysts from old (34-39 weeks) or young (8-9 weeks) C57BL/6 females mated with young CBA males (13-15 weeks) were either subjected to differential cell staining (inner cell mass and trophectoderm) or underwent embryo transfer (ET) into young MF1 surrogates (8-9 weeks) to produce young (Young-ET, 9 litters) and old (Old-ET, 10 litters) embryo-derived offspring. Offspring health monitoring was carried out for 30 weeks. PARTICIPANTS/MATERIALS, SETTING, METHODS All animals were fed with standard chow. Blood pressure was measured at post-natal Weeks 9, 15 and 21, and at post-natal Week 30 a glucose tolerance test (GTT) was performed. Two days after the GTT mice were killed for organ allometry. Blastocyst cell allocation variables were evaluated by T-test and developmental data were analysed with a multilevel random effects regression model. MAIN RESULTS AND THE ROLE OF CHANCE The total number of cells in blastocysts from aged mice was decreased (P < 0.05) relative to young mice due to a lower number of cells in the trophectoderm (mean ± SEM: 34.5 ± 2.1 versus 29.6 ± 1.0). Weekly body weight did not differ in male offspring, but an increase in body weight from Week 13 onwards was observed in Old-ET females (final body weight at post-natal Week 30: 38.5 ± 0.8 versus 33.4 ± 0.8 g, P < 0.05). Blood pressure was increased in Old-ET offspring at Weeks 9-15 in males (Week 9: 108.5 ± 3.13 versus 100.8 ± 1.5 mmHg, Week 15: 112.9 ± 3.2 versus 103.4 ± 2.1 mmHg) and Week 15 in females (115.9 ± 3.7 versus 102.8 ± 0.7 mmHg; all P < 0.05 versus Young-ET). The GTT results and organ allometry were not affected in male offspring. In contrast, Old-ET females displayed a greater (P < 0.05) peak glucose concentration at 30 min during the GTT (21.1 ± 0.4 versus 17.8 ± 1.16 mmol/l) and their spleen weight (88.2 ± 2.6 ± 105.1 ± 4.6 mg) and several organ:body weight ratios (g/g × 10(3)) were decreased (P < 0.05 versus Young-ET), including the heart (3.7 ± 0.06 versus 4.4 ± 0.08), lungs (4.4 ± 0.1 versus 5.0 ± 0.1), spleen (2.4 ± 0.06 versus 3.2 ± 0.1) and liver (36.4 ± 0.6 versus 39.1 ± 0.9). LIMITATIONS, REASONS FOR CAUTION Results from experimental animal models cannot be extrapolated to humans. Nevertheless, they are valuable to develop conceptual models that can produce hypotheses for eventual testing in the target species (i.e. humans). WIDER IMPLICATIONS OF THE FINDINGS Our data show that offspring from mouse embryos from aged mothers can develop altered phenotypes during post-natal development compared with embryos from young mothers. Because all embryos were transferred into young mothers for the duration of pregnancy to normalize the maternal in vivo environment, our findings indicate that adverse programming via AMA is already established at the blastocyst stage. Whilst human embryos display increased aneuploidy compared with mouse, we believe our data have implications for women of AMA undergoing assisted reproduction, including surrogacy programmes. STUDY FUNDING/COMPETING INTERESTS This work was supported through the European Union FP7-CP-FP Epihealth programme (278418) to T.P.F. and the BBSRC (BB/F007450/1) to T.P.F. The authors have no conflicts of interest to declare.
Collapse
Affiliation(s)
- M A Velazquez
- Centre for Biological Sciences, University of Southampton, Southampton SO16 6YD, UK School of Agriculture, Food & Rural Development, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK
| | - C G C Smith
- Centre for Biological Sciences, University of Southampton, Southampton SO16 6YD, UK
| | - N R Smyth
- Centre for Biological Sciences, University of Southampton, Southampton SO16 6YD, UK
| | - C Osmond
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton SO16 6YD, UK
| | - T P Fleming
- Centre for Biological Sciences, University of Southampton, Southampton SO16 6YD, UK
| |
Collapse
|
18
|
Johnson GD, Jodar M, Pique-Regi R, Krawetz SA. Nuclease Footprints in Sperm Project Past and Future Chromatin Regulatory Events. Sci Rep 2016; 6:25864. [PMID: 27184706 PMCID: PMC4869110 DOI: 10.1038/srep25864] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 04/22/2016] [Indexed: 01/08/2023] Open
Abstract
Nuclear remodeling to a condensed state is a hallmark of spermatogenesis. This is achieved by replacement of histones with protamines. Regions retaining nucleosomes may be of functional significance. To determine their potential roles, sperm from wild type and transgenic mice harboring a single copy insert of the human protamine cluster were subjected to Micrococcal Nuclease-seq. CENTIPEDE, a hierarchical Bayesian model, was used to identify multiple spatial patterns, "footprints", of MNase-seq reads along the sperm genome. Regions predicted by CENTIPEDE analysis to be bound by a regulatory factor in sperm were correlated with genomic landmarks and higher order chromatin structure datasets to identify potential roles for these factors in regulating either prior or post spermatogenic, i.e., early embryonic events. This approach linked robust endogenous protamine transcription and transgene suppression to its chromatin environment within topologically associated domains. Of the candidate enhancer-bound regulatory proteins, Ctcf, was associated with chromatin domain boundaries in testes and embryonic stem cells. The continuity of Ctcf binding through the murine germline may permit rapid reconstitution of chromatin organization following fertilization. This likely reflects its preparation for early zygotic genome activation and comparatively accelerated preimplantation embryonic development program observed in mouse as compared to human and bull.
Collapse
Affiliation(s)
- Graham D Johnson
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Meritxell Jodar
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, 48201, USA.,Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Roger Pique-Regi
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, 48201, USA.,Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Stephen A Krawetz
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, 48201, USA.,Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| |
Collapse
|
19
|
Bolton H, Graham SJL, Van der Aa N, Kumar P, Theunis K, Fernandez Gallardo E, Voet T, Zernicka-Goetz M. Mouse model of chromosome mosaicism reveals lineage-specific depletion of aneuploid cells and normal developmental potential. Nat Commun 2016; 7:11165. [PMID: 27021558 PMCID: PMC4820631 DOI: 10.1038/ncomms11165] [Citation(s) in RCA: 283] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 02/26/2016] [Indexed: 12/23/2022] Open
Abstract
Most human pre-implantation embryos are mosaics of euploid and aneuploid cells. To determine the fate of aneuploid cells and the developmental potential of mosaic embryos, here we generate a mouse model of chromosome mosaicism. By treating embryos with a spindle assembly checkpoint inhibitor during the four- to eight-cell division, we efficiently generate aneuploid cells, resulting in embryo death during peri-implantation development. Live-embryo imaging and single-cell tracking in chimeric embryos, containing aneuploid and euploid cells, reveal that the fate of aneuploid cells depends on lineage: aneuploid cells in the fetal lineage are eliminated by apoptosis, whereas those in the placental lineage show severe proliferative defects. Overall, the proportion of aneuploid cells is progressively depleted from the blastocyst stage onwards. Finally, we show that mosaic embryos have full developmental potential, provided they contain sufficient euploid cells, a finding of significance for the assessment of embryo vitality in the clinic. The developmental potential of mosaic embryos of euploid and aneuploid cells is unknown. Here, the authors create a mouse model of chromosome mosaicism, showing that aneuploid cells in the fetus are eliminated by apoptosis and developmental potential is dependent on the presence of sufficient euploid cells.
Collapse
Affiliation(s)
- Helen Bolton
- Department of Physiology, Development and Neuroscience and Gurdon Institute, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
| | - Sarah J L Graham
- Department of Physiology, Development and Neuroscience and Gurdon Institute, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
| | - Niels Van der Aa
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven 3000, Belgium
| | - Parveen Kumar
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven 3000, Belgium
| | - Koen Theunis
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven 3000, Belgium
| | | | - Thierry Voet
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven 3000, Belgium.,Sanger Institute-EBI Single-Cell Genomics Centre, Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK
| | - Magdalena Zernicka-Goetz
- Department of Physiology, Development and Neuroscience and Gurdon Institute, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
| |
Collapse
|