1
|
Soszyńska A, Krawczyk K, Szpila M, Winek E, Szpakowska A, Suwińska A. Exposure of chimaeric embryos to exogenous FGF4 leads to the production of pure ESC-derived mice. Theriogenology 2024; 222:10-21. [PMID: 38603966 DOI: 10.1016/j.theriogenology.2024.03.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 03/28/2024] [Accepted: 03/31/2024] [Indexed: 04/13/2024]
Abstract
Producing chimaeras constitutes the most reliable method of verifying the pluripotency of newly established cells. Moreover, forming chimaeras by injecting genetically modified embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) into the embryo is part of the procedure for generating transgenic mice, which are used for understanding gene function. Conventional methods for generating transgenic mice, including the breeding of chimaeras and tetraploid complementation, are time-consuming and cost-inefficient, with significant limitations that hinder their effectiveness and widespread applications. In the present study, we modified the traditional method of chimaera generation to significantly speed up this process by generating mice exclusively derived from ESCs. This study aimed to assess whether fully ESC-derived mice could be obtained by modulating fibroblast growth factor 4 (FGF4) levels in the culture medium and changing the direction of cell differentiation in the chimaeric embryo. We found that exogenous FGF4 directs all host blastomeres to the primitive endoderm fate, but does not affect the localisation of ESCs in the epiblast of the chimaeric embryos. Consequently, all FGF4-treated chimaeric embryos contained an epiblast composed exclusively of ESCs, and following transfer into recipient mice, these embryos developed into fully ESC-derived newborns. Collectively, this simple approach could accelerate the generation of ESC-derived animals and thus optimise ESC-mediated transgenesis and the verification of cell pluripotency. Compared to traditional methods, it could speed up functional studies by several weeks and significantly reduce costs related to maintaining and breeding chimaeras. Moreover, since the effect of stimulating the FGF signalling pathway is universal across different animal species, our approach can be applied not only to rodents but also to other animals, offering its utility beyond laboratory settings.
Collapse
Affiliation(s)
- Anna Soszyńska
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland.
| | - Katarzyna Krawczyk
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland.
| | - Marcin Szpila
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland.
| | - Eliza Winek
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland.
| | - Anna Szpakowska
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland.
| | - Aneta Suwińska
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland.
| |
Collapse
|
2
|
Association of mitofusin 2 methylation and essential hypertension: a case-control study in a Chinese population. Hypertens Res 2018; 41:605-613. [DOI: 10.1038/s41440-018-0057-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/10/2017] [Accepted: 12/26/2017] [Indexed: 12/13/2022]
|
3
|
MERVL/Zscan4 Network Activation Results in Transient Genome-wide DNA Demethylation of mESCs. Cell Rep 2017; 17:179-192. [PMID: 27681430 PMCID: PMC5055476 DOI: 10.1016/j.celrep.2016.08.087] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 07/19/2016] [Accepted: 08/25/2016] [Indexed: 12/30/2022] Open
Abstract
Mouse embryonic stem cells are dynamic and heterogeneous. For example, rare cells cycle through a state characterized by decondensed chromatin and expression of transcripts, including the Zscan4 cluster and MERVL endogenous retrovirus, which are usually restricted to preimplantation embryos. Here, we further characterize the dynamics and consequences of this transient cell state. Single-cell transcriptomics identified the earliest upregulated transcripts as cells enter the MERVL/Zscan4 state. The MERVL/Zscan4 transcriptional network was also upregulated during induced pluripotent stem cell reprogramming. Genome-wide DNA methylation and chromatin analyses revealed global DNA hypomethylation accompanying increased chromatin accessibility. This transient DNA demethylation was driven by a loss of DNA methyltransferase proteins in the cells and occurred genome-wide. While methylation levels were restored once cells exit this state, genomic imprints remained hypomethylated, demonstrating a potential global and enduring influence of endogenous retroviral activation on the epigenome. Single-cell transcriptomics reveals dynamics of MERVL/Zscan4 network activation MERVL-LTR transcriptional network is expressed in iPSC reprogramming events Translation block depletes Dnmt proteins, inducing transient global demethylation Passage through the MERVL/Zscan4 state may cause irreversible imprint erasure
Collapse
|
4
|
MERVL/Zscan4 Network Activation Results in Transient Genome-wide DNA Demethylation of mESCs. Cell Rep 2016. [PMID: 27681430 DOI: 10.1016/j.celrep.2016.08.087.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Mouse embryonic stem cells are dynamic and heterogeneous. For example, rare cells cycle through a state characterized by decondensed chromatin and expression of transcripts, including the Zscan4 cluster and MERVL endogenous retrovirus, which are usually restricted to preimplantation embryos. Here, we further characterize the dynamics and consequences of this transient cell state. Single-cell transcriptomics identified the earliest upregulated transcripts as cells enter the MERVL/Zscan4 state. The MERVL/Zscan4 transcriptional network was also upregulated during induced pluripotent stem cell reprogramming. Genome-wide DNA methylation and chromatin analyses revealed global DNA hypomethylation accompanying increased chromatin accessibility. This transient DNA demethylation was driven by a loss of DNA methyltransferase proteins in the cells and occurred genome-wide. While methylation levels were restored once cells exit this state, genomic imprints remained hypomethylated, demonstrating a potential global and enduring influence of endogenous retroviral activation on the epigenome.
Collapse
|
5
|
He J, Sun MA, Wang Z, Wang Q, Li Q, Xie H. Characterization and machine learning prediction of allele-specific DNA methylation. Genomics 2015; 106:331-9. [PMID: 26407641 DOI: 10.1016/j.ygeno.2015.09.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 09/15/2015] [Accepted: 09/20/2015] [Indexed: 12/23/2022]
Abstract
A large collection of Single Nucleotide Polymorphisms (SNPs) has been identified in the human genome. Currently, the epigenetic influences of SNPs on their neighboring CpG sites remain elusive. A growing body of evidence suggests that locus-specific information, including genomic features and local epigenetic state, may play important roles in the epigenetic readout of SNPs. In this study, we made use of mouse methylomes with known SNPs to develop statistical models for the prediction of SNP associated allele-specific DNA methylation (ASM). ASM has been classified into parent-of-origin dependent ASM (P-ASM) and sequence-dependent ASM (S-ASM), which comprises scattered-S-ASM (sS-ASM) and clustered-S-ASM (cS-ASM). We found that P-ASM and cS-ASM CpG sites are both enriched in CpG rich regions, promoters and exons, while sS-ASM CpG sites are enriched in simple repeat and regions with high frequent SNP occurrence. Using Lasso-grouped Logistic Regression (LGLR), we selected 21 out of 282 genomic and methylation related features that are powerful in distinguishing cS-ASM CpG sites and trained the classifiers with machine learning techniques. Based on 5-fold cross-validation, the logistic regression classifier was found to be the best for cS-ASM prediction with an ACC of 0.77, an AUC of 0.84 and an MCC of 0.54. Lastly, we applied the logistic regression classifier on human brain methylome and predicted 608 genes associated with cS-ASM. Gene ontology term enrichment analysis indicated that these cS-ASM associated genes are significantly enriched in the category coding for transcripts with alternative splicing forms. In summary, this study provided an analytical procedure for cS-ASM prediction and shed new light on the understanding of different types of ASM events.
Collapse
Affiliation(s)
- Jianlin He
- Laboratory of Genome Variation and Precision Biomedicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Ming-an Sun
- Epigenomics and Computational Biology Lab, Virginia Bioinformatics Institute, Virginia Tech, VA 24060, USA.
| | - Zhong Wang
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510080, China; Center for Cellular & Structural Biology, Sun Yat-Sen University, Guangzhou 510080, China.
| | - Qianfei Wang
- Laboratory of Genome Variation and Precision Biomedicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Qing Li
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510080, China; Center for Cellular & Structural Biology, Sun Yat-Sen University, Guangzhou 510080, China.
| | - Hehuang Xie
- Laboratory of Genome Variation and Precision Biomedicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; Epigenomics and Computational Biology Lab, Virginia Bioinformatics Institute, Virginia Tech, VA 24060, USA; Department of Biological Sciences, Virginia Tech, VA 24060, USA.
| |
Collapse
|
6
|
Verma A, Rajput S, De S, Kumar R, Chakravarty AK, Datta TK. Genome-wide profiling of sperm DNA methylation in relation to buffalo (Bubalus bubalis) bull fertility. Theriogenology 2014; 82:750-9.e1. [DOI: 10.1016/j.theriogenology.2014.06.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 05/31/2014] [Accepted: 06/07/2014] [Indexed: 10/25/2022]
|
7
|
Abstract
Major difficulties exist in the accurate and meaningful diagnosis of male reproductive dysfunction, and our understanding of the epidemiology and etiology of male infertility has proven quite complex.The numerous spermatozoa produced in mammals and other species provides some degree of protection against adverse environmental conditions represented by physical and chemical factors that can reduce reproductive function and increase gonadal damage even resulting in testicular cancer or congenital malformations. The wide fluctuations of sperm production in men, both geographical and temporal, may reflect disparate environmental exposures, occurring on differing genetic backgrounds, in varying psychosocial conditions, and leading to the diversified observed outcomes.Sperm analysis is still the cornerstone in diagnosis of male factor infertility, indeed, individually compromised semen paramaters while adequately address therapeutic practices is progressively flanked by additional tests. Administration of drugs, IUI, correction of varicocele, and, to a certain extent, IVF although they may not be capable of restoring fertility itself often result in childbearing.
Collapse
Affiliation(s)
- Gianpiero D Palermo
- The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medical College, 1305 York Avenue, Suite 720, New York, NY, 10021, USA,
| | | | | | | | | |
Collapse
|
8
|
Shan ZY, Wu YS, Shen XH, Li X, Xue Y, Zheng Z, Wang ZD, Liu CJ, Sun RZ, Li ZY, Shen JL, Liu ZH, Lei L. Aggregation of pre-implantation embryos improves establishment of parthenogenetic stem cells and expression of imprinted genes. Dev Growth Differ 2012; 54:481-8. [PMID: 22435468 DOI: 10.1111/j.1440-169x.2012.01335.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 02/02/2012] [Accepted: 02/02/2012] [Indexed: 11/27/2022]
Abstract
Parthenogenetic embryonic stem cells (PgES) might advance cell replacement therapies and provide a valuable in vitro model system to study the genomic imprinting. However, the differential potential of PgES cells was limited. It could result from relative low heterology of PgES cells compared with ES cells from fertilization (fES), which produce different expression of most imprinted genes. Here, we described the establishment of PgES cells by aggregating parthenogenetic embryos at the 8-cell stage (aPgES cells), which may increase heterozygy. We found that derivation of aPgES cells in association with an increased number of inner cell mass cells by aggregating was more efficient than that of PgES cells from a single parthenogenetic blastocyst. The aPgES cells have normal karyotype, stain positive for alkaline phosphatase, express high levels of ES cell markers and can differentiate into teratomas composed of the three germ layers. Moreover, compared with PgES cells, the more highly upregulated paternally expressed imprinted genes were observed in aPgES cells, the same change was not shown in aPg blastocysts. This suggested that the aggregation induced effect could modify the expression of paternally expressed imprinted genes. Our studies showed that aPgES cells, the expression of imprinted genes in which more closely resemble fES cells than PgES cells, would contribute to all organs and avoiding immuno-rejection, which may provide invaluable material for regeneration medicine.
Collapse
Affiliation(s)
- Zhi-Yan Shan
- Department of Histology and Embryology, Harbin Medical University, Harbin, China
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Liang M, Yang JL, Bian MJ, Liu J, Hong XQ, Wang YC, Huang YF, Gu SP, Yu M, Huang F, Fei J. Requirement of regulated endocrine-specific protein-18 for development and expression of regulated endocrine-specific protein-18 isoform c in mice. Mol Biol Rep 2010; 38:2557-62. [PMID: 21104147 DOI: 10.1007/s11033-010-0394-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Accepted: 11/08/2010] [Indexed: 11/30/2022]
Abstract
Regulated endocrine-specific protein-18 (RESP18) is distributed mainly in the peripheral endocrine and neuroendocrine tissues. The expression of RESP18 protein is regulated by physiological factors, such as blood glucose or dopaminergic drugs, but its functions remain unclear. In this study, to explore the biological functions of RESP18 in vivo, we generated RESP18 heterozygous deficient mice, and further found RESP18 was essential for embryonic development. In addition, we cloned a new isoform of mouse RESP18 by reverse transcription-polymerase chain reaction (RT-PCR), and denominated it as RESP18-c. Mouse RESP18-c, by skipping exon4 (43 bp in length), encodes a shorter protein of 120 amino acid residues. The distribution of RESP18-c mRNA is similar with that of RESP18 mRNA in the peripheral tissues and brains of mice.
Collapse
Affiliation(s)
- Min Liang
- State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai, 200032, People's Republic of China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Farin CE, Farmer WT, Farin PW. Pregnancy recognition and abnormal offspring syndrome in cattle. Reprod Fertil Dev 2010; 22:75-87. [DOI: 10.1071/rd09217] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Development of the post-hatching conceptus in ruminants involves a period of morphological expansion that is driven by complex interactions between the conceptus and its intrauterine environment. As a result of these interactions, endometrial physiology is altered, leading to establishment of the pregnancy and continued development of the placenta. Disruption of normal fetal and placental development can occur when embryos are exposed to manipulations in vitro or when inappropriate endocrine sequencing occurs in vivo during the pre- and peri-implantation periods. The present review addresses the development of the post-hatching bovine conceptus, its interactions with the maternal system and changes in development that can occur as a result of in vivo and in vitro manipulations of the bovine embryo.
Collapse
|
11
|
Deng T, Kuang Y, Wang L, Li J, Wang Z, Fei J. An essential role for DNA methyltransferase 3a in melanoma tumorigenesis. Biochem Biophys Res Commun 2009; 387:611-6. [PMID: 19632198 DOI: 10.1016/j.bbrc.2009.07.093] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Accepted: 07/19/2009] [Indexed: 11/17/2022]
Abstract
Abnormal DNA methylation and associated silencing of tumor suppressor genes are common to many types of cancers. Among the three coordinate DNA methyltransferases (Dnmts), Dnmt1 and Dnmt3b were both shown to be important for cancer cell survival and tumorigenesis. However, the relationship between Dnmt3a and tumorigenesis is still largely unknown. Here, we show that inhibition of Dnmt3a expression, by stable transfection of a Dnmt3a-RNA interference (RNAi) construct dramatically inhibited melanoma growth and metastasis in mouse melanoma models. Microarray analysis revealed that genes critical for the tumor immune response, were implicated in the inhibition of melanoma growth. Expression of a cluster of class I and class II MHC genes, class II transactivator (Ciita), as well as a subset of 5 chemokines (Cxcl9, Cxcl16, Ccl12, Ccl4, and Ccl2) were up-regulated. Furthermore, we determined that the promoter IV of Ciita was significantly demethylated in Dnmt3a-depleted tumors. In addition, several known tumor-related genes, which are critical for developmental processes and cell cycle, were confirmed to be misregulated, including TgfB1, Socs1, Socs2, E2F6, Ccne1, and Cyr61. The results presented in this report strongly suggest that Dnmt3a plays an essential role in melanoma tumorigenesis, and that the underlying mechanisms include the modulation of the tumor immune response, as well as other processes.
Collapse
Affiliation(s)
- Tao Deng
- Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | | | | | | | | | | |
Collapse
|
12
|
Oh SH, Jung YH, Gupta MK, Uhm SJ, Lee HT. H19 gene is epigenetically stable in mouse multipotent germline stem cells. Mol Cells 2009; 27:635-40. [PMID: 19533039 DOI: 10.1007/s10059-009-0084-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Revised: 04/14/2009] [Accepted: 04/21/2009] [Indexed: 01/14/2023] Open
Abstract
Testis-derived germline stem (GS) cells can undergo re-programming to acquire multipotency when cultured under appropriate culture conditions. These multipotent GS (mGS) cells have been known to differ from GS cells in their DNA methylation pattern. In this study, we examined the DNA methylation status of the H19 imprinting control region (ICR) in multipotent adult germline stem (maGS) cells to elucidate how epigenetic imprints are altered by culture conditions. DNA methylation was analyzed by bisulfite sequencing PCR of established maGS cells cultured in the presence of glial cell line-derived neurotrophic factor (GDNF) alone or both GDNF and leukemia inhibitory factor (LIF). The results showed that the H19 ICR in maGS cells of both groups was hypermethylated and had an androgenetic pattern similar to that of GS cells. In line with these data, the relative abundance of the Igf2 mRNA transcript was two-fold higher and that of H19 was three fold lower than in control embryonic stem cells. The androgenetic DNA methylation pattern of the H19 ICR was maintained even after 54 passages. Furthermore, differentiating maGS cells from retinoic acid-treated embryoid bodies maintained the androgenetic imprinting pattern of the H19 ICR. Taken together these data suggest that our maGS cells are epigenetically stable for the H19 gene during in vitro modifications. Further studies on the epigenetic regulation and chromatin structure of maGS cells are therefore necessary before their full potential can be utilized in regenerative medicine.
Collapse
Affiliation(s)
- Shin Hye Oh
- Department of Bioscience and Biotechnology, Bio-Organ Research Center, Konkuk University, Seoul 143-701, Korea
| | | | | | | | | |
Collapse
|
13
|
Madan B, Madan V, Weber O, Tropel P, Blum C, Kieffer E, Viville S, Fehling HJ. The pluripotency-associated gene Dppa4 is dispensable for embryonic stem cell identity and germ cell development but essential for embryogenesis. Mol Cell Biol 2009; 29:3186-203. [PMID: 19332562 PMCID: PMC2682008 DOI: 10.1128/mcb.01970-08] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Revised: 03/04/2009] [Accepted: 03/19/2009] [Indexed: 12/12/2022] Open
Abstract
Dppa4 (developmental pluripotency-associated 4) has been identified in several high-profile screens as a gene that is expressed exclusively in pluripotent cells. It encodes a nuclear protein with an SAP-like domain and appears to be associated preferentially with transcriptionally active chromatin. Its exquisite expression pattern and results of RNA interference experiments have led to speculation that Dppa4, as well as its nearby homolog Dppa2, might play essential roles in embryonic stem (ES) cell function and/or germ cell development. To rigorously assess suggested roles, we have generated Dppa4-deficient and Dppa4/Dppa2 doubly deficient ES cells, as well as mice lacking Dppa4. Contrary to predictions, we find that Dppa4 is completely dispensable for ES cell identity and germ cell development. Instead, loss of Dppa4 in mice results in late embryonic/perinatal death and striking skeletal defects with partial penetrance. Thus, surprisingly, Dppa4-deficiency affects tissues that apparently never transcribed the gene, and at least some loss-of-function defects manifest phenotypically at an embryonic stage long after physiologic Dppa4 expression has ceased. Concomitant with targeted gene inactivation, we have introduced into the Dppa4 locus a red fluorescent marker (tandem-dimer red fluorescent protein) that is compatible with green fluorescent proteins and allows noninvasive visualization of pluripotent cells and reprogramming events.
Collapse
Affiliation(s)
- Babita Madan
- Institute of Immunology, University Clinics Ulm, Ulm, Germany
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Carrell DT. Contributions of spermatozoa to embryogenesis: assays to evaluate their genetic and epigenetic fitness. Reprod Biomed Online 2008; 16:474-84. [PMID: 18413055 DOI: 10.1016/s1472-6483(10)60454-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
During fertilization, spermatozoa contribute genetic and epigenetic factors that affect early embryogenesis. Genetic factors include a haploid genome with intact coding regions and regulatory regions for essential genes. The DNA must contain the proper copy number of essential genes, and cannot have increased single- or double- stranded DNA breaks. Epigenetic factors include a functional centrosome, proper packaging of the chromatin with protamines, modifications of histones, and imprinting of genes. Additionally, the fertilizing spermatozoon provides mRNAs and micro RNAs, which may contribute to the embryonic transcriptome and regulate embryonic gene expression. These epigenetic factors, directly or indirectly, affect the expression of genes in the developing embryo. Each of these contributions represents areas of potential sperm dysfunction, and they are the focus of ongoing research to develop assays which will allow further analysis of their clinical significance. This review briefly describes the current status of research into the genetic and epigenetic contributions of spermatozoa to embryogenesis, and the quest for clinical screening assays. The challenges to validation and clinical application of such testing are also discussed.
Collapse
Affiliation(s)
- Douglas T Carrell
- IVF and Andrology Laboratories, Department of Surgery (Urology), University of Utah School of Medicine, Salt Lake City, Utah, USA.
| |
Collapse
|
15
|
Keverne EB, Curley JP. Epigenetics, brain evolution and behaviour. Front Neuroendocrinol 2008; 29:398-412. [PMID: 18439660 DOI: 10.1016/j.yfrne.2008.03.001] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Revised: 11/30/2007] [Accepted: 03/01/2008] [Indexed: 12/14/2022]
Abstract
Molecular modifications to the structure of histone proteins and DNA (chromatin) play a significant role in regulating the transcription of genes without altering their nucleotide sequence. Certain epigenetic modifications to DNA are heritable in the form of genomic imprinting, whereby subsets of genes are silenced according to parent-of-origin. This form of gene regulation is primarily under matrilineal control and has evolved partly to co-ordinate in-utero development with maternal resource availability. Changes to epigenetic mechanisms in post-mitotic neurons may also be activated during development in response to environmental stimuli such as maternal care and social interactions. This results in long-lasting stable, or short-term dynamic, changes to the neuronal phenotype producing long-term behavioural consequences. Use of evolutionary conserved mechanisms have thus been adapted to modify the control of gene expression and embryonic growth of the brain as well as allowing for plastic changes in the post-natal brain in response to external environmental and social cues.
Collapse
Affiliation(s)
- Eric B Keverne
- Sub-Department of Animal Behaviour, University of Cambridge, Madingley, Cambridge, CB23 8AA, UK.
| | | |
Collapse
|
16
|
Gao S, Wen X, Yang R, Di K, Tong J, Li X. Decreased surfactant protein B expression in mice derived completely from embryonic stem cells. In Vitro Cell Dev Biol Anim 2007; 44:10-6. [PMID: 18074187 DOI: 10.1007/s11626-007-9070-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Accepted: 10/24/2007] [Indexed: 11/27/2022]
Abstract
ES mice that are derived completely from embryonic stem (ES) cells can be obtained by tetraploid embryo complementation. Many neonate ES mice die because of respiratory distress, but it is not clear what contributes to the phenomenon. Using five microsatellite DNA markers, we confirmed that our ES mice were completely derived from ES cells and contained no tetraploid component. The neonatal ES mice that exhibited respiratory distress were tested for surfactant protein B (SP-B) expression by Western blotting. These mice had no SP-B expression, and even apparently healthy adult ES mice had decreased SP-B levels and aberrant SP-B phenotypes. These data suggest that the expression of SP-B protein is an important factor in the survival of ES mice to term and adulthood.
Collapse
Affiliation(s)
- Shumin Gao
- College of Animal Science and Technology, Agricultural University of Hebei, Baoding, Hebei, China
| | | | | | | | | | | |
Collapse
|