1
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Tracking the dynamics of female germ cell development during peri-hatch periods using a gene-edited chicken model. Poult Sci 2022; 102:102377. [PMID: 36586387 PMCID: PMC9811252 DOI: 10.1016/j.psj.2022.102377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 11/15/2022] [Accepted: 11/30/2022] [Indexed: 12/13/2022] Open
Abstract
In hens, egg production depends on the development of germ cells in the ovary. Germ cells are established before birth, and their number gradually decreases during their lifespan. Therefore, it is essential to determine the time points of massive germ cell loss and the underlying mechanism. In this study, a gene-edited chicken with mCherry fluorescence specifically expressed in the germline was generated by the integration of the mCherry gene into the 3'-end of the DAZL locus, which facilitated the isolation of germ cells from the gonads of DAZL-mCherry embryos or chicks and quantification using flow cytometry based on the observation of red fluorescence. The results demonstrated the dynamics of germ cell development from embryos at 17 d of hatching (dh) to chickens at 7 d post-hatch (dph) and revealed a substantial loss of germ cells in the late embryonic stage (18 -19 dh) and post-hatch period (2 -3 dph). Additionally, the number of germ cells in DAZL × Guangxi Ma chicken was significantly higher than that in DAZL × Lohmann Pink chicken at 19 dh and 3 dph (P < 0.05). Furthermore, the numbers of germ cells positively correlated with the body weight in DAZL × Lohmann Pink chicken. In conclusion, our results showed the dynamics of germ cell development in chicken ovaries during peri-hatch periods and indicated the time point of substantial germ cell loss. The results provide evidence for further exploration of the underlying mechanism and serve as a reference for chicken breeding and management.
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2
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Du G, Oatley MJ, Law NC, Robbins C, Wu X, Oatley JM. Proper timing of a quiescence period in precursor prospermatogonia is required for stem cell pool establishment in the male germline. Development 2021; 148:261737. [PMID: 33929507 DOI: 10.1242/dev.194571] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 03/30/2021] [Indexed: 11/20/2022]
Abstract
The stem cell-containing undifferentiated spermatogonial population in mammals, which ensures continual sperm production, arises during development from prospermatogonial precursors. Although a period of quiescence is known to occur in prospermatogonia prior to postnatal spermatogonial transition, the importance of this has not been defined. Here, using mouse models with conditional knockout of the master cell cycle regulator Rb1 to disrupt normal timing of the quiescence period, we found that failure to initiate mitotic arrest during fetal development leads to prospermatogonial apoptosis and germline ablation. Outcomes of single-cell RNA-sequencing analysis indicate that oxidative phosphorylation activity and inhibition of meiotic initiation are disrupted in prospermatogonia that fail to enter quiescence on a normal timeline. Taken together, these findings suggest that key layers of programming are laid down during the quiescent period in prospermatogonia to ensure proper fate specification and fitness in postnatal life.
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Affiliation(s)
- Guihua Du
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu, 211166, China.,School of Molecular Biosciences, Center for Reproductive Biology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
| | - Melissa J Oatley
- School of Molecular Biosciences, Center for Reproductive Biology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
| | - Nathan C Law
- School of Molecular Biosciences, Center for Reproductive Biology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
| | - Colton Robbins
- School of Molecular Biosciences, Center for Reproductive Biology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
| | - Xin Wu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu, 211166, China
| | - Jon M Oatley
- School of Molecular Biosciences, Center for Reproductive Biology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
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3
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Parekh PA, Garcia TX, Hofmann MC. Regulation of GDNF expression in Sertoli cells. Reproduction 2020; 157:R95-R107. [PMID: 30620720 DOI: 10.1530/rep-18-0239] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 01/08/2019] [Indexed: 12/15/2022]
Abstract
Sertoli cells regulate male germ cell proliferation and differentiation and are a critical component of the spermatogonial stem cell (SSC) niche, where homeostasis is maintained by the interplay of several signaling pathways and growth factors. These factors are secreted by Sertoli cells located within the seminiferous epithelium, and by interstitial cells residing between the seminiferous tubules. Sertoli cells and peritubular myoid cells produce glial cell line-derived neurotrophic factor (GDNF), which binds to the RET/GFRA1 receptor complex at the surface of undifferentiated spermatogonia. GDNF is known for its ability to drive SSC self-renewal and proliferation of their direct cell progeny. Even though the effects of GDNF are well studied, our understanding of the regulation its expression is still limited. The purpose of this review is to discuss how GDNF expression in Sertoli cells is modulated within the niche, and how these mechanisms impact germ cell homeostasis.
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Affiliation(s)
- Parag A Parekh
- Department of Endocrine Neoplasia, UT MD Anderson Cancer Center, Houston, Texas, USA
| | - Thomas X Garcia
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, USA.,Department of Biological and Environmental Sciences, University of Houston-Clear Lake, Houston, Texas, USA
| | - Marie-Claude Hofmann
- Department of Endocrine Neoplasia, UT MD Anderson Cancer Center, Houston, Texas, USA
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4
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Li H, Liang Z, Yang J, Wang D, Wang H, Zhu M, Geng B, Xu EY. DAZL is a master translational regulator of murine spermatogenesis. Natl Sci Rev 2019; 6:455-468. [PMID: 31355046 PMCID: PMC6660020 DOI: 10.1093/nsr/nwy163] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/12/2018] [Accepted: 12/27/2018] [Indexed: 12/30/2022] Open
Abstract
Expression of DAZ-like (DAZL) is a hallmark of vertebrate germ cells, and is essential for embryonic germ cell development and differentiation, yet the gametogenic function of DAZL has not been fully characterized and most of its in vivo direct targets remain unknown. We showed that postnatal stage-specific deletion of Dazl in mouse germ cells did not affect female fertility, but caused complete male sterility with gradual loss of spermatogonial stem cells, meiotic arrest and spermatid arrest. Using the genome-wide high-throughput sequencing of RNAs isolated by cross-linking immunoprecipitation and mass spectrometry approach, we found that DAZL bound to a large number of testicular mRNA transcripts (at least 3008) at the 3'-untranslated region and interacted with translation proteins including poly(A) binding protein. In the absence of DAZL, polysome-associated target transcripts, but not their total transcripts, were significantly decreased, resulting in a drastic reduction of an array of spermatogenic proteins and thus developmental arrest. Thus, DAZL is a master translational regulator essential for spermatogenesis.
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Affiliation(s)
- Haixin Li
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Zhuqing Liang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Jian Yang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Dan Wang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Hanben Wang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Mengyi Zhu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Baobao Geng
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
| | - Eugene Yujun Xu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China
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5
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Niedenberger BA, Geyer CB. Advanced immunostaining approaches to study early male germ cell development. Stem Cell Res 2018; 27:162-168. [PMID: 29475796 PMCID: PMC5894494 DOI: 10.1016/j.scr.2018.01.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 01/12/2018] [Accepted: 01/19/2018] [Indexed: 12/16/2022] Open
Abstract
Mammalian male germ cell development takes place in the testis under the influence of a variety of somatic cells and an incompletely defined paracrine and endocrine influences. Since it is not recapitulated well in vitro, researchers studying spermatogenesis often manipulate the germline by creating transgenic or knockout mice or by administering pharmaceutical agonists/antagonists or inhibitors. The effects of these types of manipulations on germline development can often be determined following microscopic imaging, both of stained and immunostained testis sections. Here, we describe approaches for microscopic analysis of the developing male germline, provide detailed protocols for a variety of immunostaining approaches, and discuss transgenic fluorescent reporter lines for studying the early stages of spermatogenesis.
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Affiliation(s)
- Bryan A Niedenberger
- East Carolina Diabetes and Obesity Institute East Carolina University, Greenville, NC, USA
| | - Christopher B Geyer
- East Carolina Diabetes and Obesity Institute East Carolina University, Greenville, NC, USA; Brody School of Medicine at East Carolina University, Greenville, NC, USA.
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6
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Gassei K, Sheng Y, Fayomi A, Mital P, Sukhwani M, Lin CC, Peters KA, Althouse A, Valli H, Orwig KE. DDX4-EGFP transgenic rat model for the study of germline development and spermatogenesis. Biol Reprod 2017; 96:707-719. [PMID: 28339678 PMCID: PMC5803776 DOI: 10.1095/biolreprod.116.142828] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 01/30/2017] [Indexed: 12/31/2022] Open
Abstract
Spermatogonial stem cells (SSC) are essential for spermatogenesis and male fertility. In addition, these adult tissue stem cells can be used as vehicles for germline modification in animal models and may have application for treating male infertility. To facilitate the investigation of SSCs and germ lineage development in rats, we generated a DEAD-box helicase 4 (DDX4) (VASA) promoter-enhanced green fluorescent protein (EGFP) reporter transgenic rat. Quantitative real-time polymerase chain reaction and immunofluorescence confirmed that EGFP was expressed in the germ cells of the ovaries and testes and was absent in somatic cells and tissues. Germ cell transplantation demonstrated that the EGFP-positive germ cell population from DDX4-EGFP rat testes contained SSCs capable of establishing spermatogenesis in experimentally infertile mouse recipient testes. EGFP-positive germ cells could be easily isolated by fluorescence-activated cells sorting, while simultaneously removing testicular somatic cells from DDX4-EGFP rat pup testes. The EGFP-positive fraction provided an optimal cell suspension to establish rat SSC cultures that maintained long-term expression of zinc finger and BTB domain containing 16 (ZBTB16) and spalt-like transcription factor 4 (SALL4), two markers of mouse SSCs that are conserved in rats. The novel DDX4-EGFP germ cell reporter rat described here combined with previously described GCS-EGFP rats, rat SSC culture and gene editing tools will improve the utility of the rat model for studying stem cells and germ lineage development.
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Affiliation(s)
- Kathrin Gassei
- Department of Obstetrics, Gynecology and Reproductive Sciences and Magee-Womens Research Institute, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Yi Sheng
- Department of Obstetrics, Gynecology and Reproductive Sciences and Magee-Womens Research Institute, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | | | - Payal Mital
- Sawai Man Singh Medical College and Hospital, Jaipur, India
| | - Meena Sukhwani
- Department of Obstetrics, Gynecology and Reproductive Sciences and Magee-Womens Research Institute, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Chih-Cheng Lin
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
| | - Karen A Peters
- Biology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Andrew Althouse
- Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Hanna Valli
- Department of Molecular Genetics and Developmental Biology Graduate Program, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Magee-Womens Research Institute, Pittsburgh, Pennsylvania, USA
| | - Kyle E Orwig
- Department of Obstetrics, Gynecology and Reproductive Sciences and Magee-Womens Research Institute, University of Pittsburgh School of Medicine, Pittsburgh, USA
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7
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Hamra FK, Richie CT, Harvey BK. Long Evans rat spermatogonial lines are effective germline vectors for transgenic rat production. Transgenic Res 2017; 26:477-489. [PMID: 28608322 DOI: 10.1007/s11248-017-0025-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 05/25/2017] [Indexed: 11/24/2022]
Abstract
Long Evans rat strains are applied as research models in a broad spectrum of biomedical fields (>15,800 citations, NCBI PubMed). Here, we report an approach to genetically modify the Long Evans rat germline in donor spermatogonial stem cells. Long Evans rat spermatogonial lines were derived from freshly isolated laminin-binding spermatogonia. Laminin-binding spermatogonia were cultured over multiple passages on fibroblast feeder layers in serum-free culture medium containing GDNF and FGF2. Long Evans rat spermatogonial lines were genetically modified by transposon transduction to express a germline, tdTomato reporter gene. Donor rat spermatogonial lines robustly regenerated spermatogenesis after transplantation into testes of busulfan-treated, allogenic, Long Evans rats. Donor-derived spermatogenesis largely restored testis size in the chemically sterilized, recipient Long Evans rats. Recipient Long Evans rats stably transmitted the tdTomato germline marker to subsequent generations. Overall, Long Evans rat spermatogonial lines provided effective donor germline vectors for genetically modifying Long Evans rats.
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Affiliation(s)
- F Kent Hamra
- Department of Pharmacology, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX, 75390, USA. .,Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA. .,Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
| | - Christopher T Richie
- National Institute on Drug Abuse, National Institutes of Health, 251 Bayview Blvd, Baltimore, MD, 21224, USA
| | - Brandon K Harvey
- National Institute on Drug Abuse, National Institutes of Health, 251 Bayview Blvd, Baltimore, MD, 21224, USA
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8
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Garcia TX, Parekh P, Gandhi P, Sinha K, Hofmann MC. The NOTCH Ligand JAG1 Regulates GDNF Expression in Sertoli Cells. Stem Cells Dev 2017; 26:585-598. [PMID: 28051360 DOI: 10.1089/scd.2016.0318] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
In the seminiferous epithelium of the testis, Sertoli cells are key niche cells directing proliferation and differentiation of spermatogonial stem cells (SSCs) into spermatozoa. Sertoli cells produce glial cell line-derived neurotrophic factor (GDNF), which is essential for SSC self-renewal and progenitor expansion. While the role of GDNF in the testis stem cell niche is established, little is known about how this factor is regulated. Our previous studies on NOTCH activity in Sertoli cells demonstrated a role of this pathway in limiting stem/progenitor cell numbers, thus ultimately downregulating sperm cell output. In this study we demonstrate through a double-mutant mouse model that NOTCH signaling in Sertoli cells functions solely through the canonical pathway. Further, we demonstrate through Dual luciferase assay and chromatin immunoprecipitation quantitative polymerase chain reaction (ChIP-qPCR) analysis that the NOTCH targets HES1 and HEY1, which are transcriptional repressors, directly downregulate GDNF expression by binding to the Gdnf promoter, thus antagonizing the effects of FSH/cAMP. Finally, we demonstrate that testicular stem/progenitors cells are activating NOTCH signaling in Sertoli cells in vivo and in vitro through the NOTCH ligand JAG1 at their surface, indicating that these cells may ensure their own homeostasis through negative feedback regulation.
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Affiliation(s)
- Thomas X Garcia
- 1 Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas, MD Anderson Cancer Center , Houston, Texas.,2 Department of Biology, University of Houston-Clear Lake , Houston, Texas
| | - Parag Parekh
- 1 Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas, MD Anderson Cancer Center , Houston, Texas
| | - Pooja Gandhi
- 1 Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas, MD Anderson Cancer Center , Houston, Texas
| | - Krishna Sinha
- 1 Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas, MD Anderson Cancer Center , Houston, Texas.,3 Department of Orthopedic Surgery, University of Texas Health Science Center , Houston, Texas
| | - Marie-Claude Hofmann
- 1 Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas, MD Anderson Cancer Center , Houston, Texas
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9
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Suzuki R, Katakura K, Fujiwara T, Gunji N, Watanabe H, Ohira H. Imiquimod-induced CCR9 Ameliorates murine TNBS Colitis. Fukushima J Med Sci 2016; 62:90-100. [PMID: 27829595 DOI: 10.5387/fms.2015-28] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
AIMS To investigate whether Imiquimod (IMQ) as TLR7 ligand protects mice from colonic inflammation and the mechanisms underlying in such immunoregulatory conditions. METHODS: Murine colitis was induced to Balb/c mice by administration of trinitrobenzene sulfonic acid (TNBS) with or without daily intraperitoneal administration of IMQ. Colitis was evaluated by body weight decreases and by histological score. Also colonic mRNA expression was measured by RT-PCR. To confirm the induction of Regulatory T cells (Tregs) by type-1 IFN from pDCs, we generated mouse bone marrow-derived pDCs and co-cultured these with CD4+ T cells isolated from mouse spleen with or without IMQ stimulation. Cytokine production in the culture supernatant was measured by ELISA and the number of Tregs were analyzed by flow cytometry. Spleen and mesenteric lymph nodes (MLN) from IMQ-treated mice were collected, and mRNA expressions of cytokine were measured by RT-PCR and cytokine productions were measured by ELISA. Tregs and chemokine expressions were analyzed in colon of TNBS-induced colitis mouse by immunohistochemistry. RESULTS: Administration of IMQ significantly suppressed colonic inflammation of TNBS-induced colitis. In the colons of IMQ-treated mice, mRNA expression of TNF-α was decreased, and strong expressions of IL-6, IFN-β and TGF-β were detected. IL-10 and TGF-β productions were increased in the supernatant of co-cultured cells stimulated with IMQ, although we were unable to detect Treg differentiaton in IMQ-stimulated co-cultured cells. In MLN of IMQ-treated mice, strong expressions of TLR7, IFN-β, TGF-β and Foxp3 mRNA were detected. IL-10 production from MLN cells was also increased in the IMQ-treated group. Finally, Tregs in the inflamed colon and CCR9 in MLN of IMQ-treated mice were detected. CONCLUSION: These results suggest that IMQ protects mice from TNBS colitis through induction of CCR9, which regulates accumulation of Tregs in the inflamed colon.
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10
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Zhang C, Xue P, Gao L, Chen X, Lin K, Yang X, Dai Y, Xu EY. Highly conserved epigenetic regulation of BOULE and DAZL is associated with human fertility. FASEB J 2016; 30:3424-3440. [PMID: 27358391 DOI: 10.1096/fj.201500167r] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 06/21/2016] [Indexed: 11/11/2022]
Abstract
Separation of germ cells from somatic cells is a widespread feature of animal sexual reproduction, with a core set of germ cell factors conserved among diverse animals. It is not known what controls their conserved gonad-specific expression. Core components of epigenetic machinery are ancient, but its role in conserved tissue expression regulation remains unexplored. We found that promoters of the reproductive genes BOULE and DAZL exhibit differential DNA methylation, consistent with their gonad-specific expression in humans and mice. Low or little promoter methylation from the testicular tissue is attributed to spermatogenic cells of various stages in the testis. Such differential DNA methylation is present in the orthologous promoters not only of other mammalian species, but also of chickens and fish, supporting a highly conserved epigenetic mechanism. Furthermore, hypermethylation of DAZL and BOULE promoters in human sperm is associated with human infertility. Our data strongly suggest that epigenetic regulation may underlie conserved germ-cell-specific expression, and such a mechanism may play an important role in human fertility.-Zhang, C., Xue, P., Gao, L., Chen, X., Lin, K., Yang, X., Dai, Y., Xu, E. Y. Highly conserved epigenetic regulation of BOULE and DAZL is associated with human fertility.
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Affiliation(s)
- Chenwang Zhang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China; and
| | - Peng Xue
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China; and Department of Urology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Liuze Gao
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China; and
| | - Xia Chen
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China; and
| | - Kaibo Lin
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China; and
| | - Xiaoyu Yang
- Department of Urology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Yifan Dai
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China; and
| | - Eugene Yujun Xu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China; and
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11
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A gonogenic stimulated transition of mouse embryonic stem cells with enhanced control of diverse differentiation pathways. Sci Rep 2016; 6:25104. [PMID: 27157261 PMCID: PMC4860597 DOI: 10.1038/srep25104] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 04/08/2016] [Indexed: 11/17/2022] Open
Abstract
Embryonic stem (ES) cells share markers with undifferentiated primordial germ cells (PGCs). Here, we discovered that a cellular state with some molecular markers of male gonocyte induction, including a G1/S phase arrest and upregulation of specific genes such as Nanos2, Tdrd1, Ddx4, Zbtb16 and Plk1s1, can be chemically induced in male mouse ES cells in vitro, which we termed gonogenic stimulated transition (GoST). After longer culture of the resulting GoST cells without chemical stimulation, several molecular markers typical for early gonocytes were detected including the early gonocyte marker Tex101. Motivated by previous studies that found multipotency in cell lines derived from neonatal male germ cells in vitro, we then compared the differentiation potential of GoST cells to that of ES cells in vitro. Interestingly, GoST cells showed equal neurogenic, but enhanced cardiogenic and hepatogenic differentiation compared to ES cells in vitro. This work shows for the first time that some important molecular markers of the first developmental sexual differentiation program can be induced in male mouse ES cells in vitro and defines a novel concept to generate cells with enhanced multipotency.
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12
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da Cruz I, Rodríguez-Casuriaga R, Santiñaque FF, Farías J, Curti G, Capoano CA, Folle GA, Benavente R, Sotelo-Silveira JR, Geisinger A. Transcriptome analysis of highly purified mouse spermatogenic cell populations: gene expression signatures switch from meiotic-to postmeiotic-related processes at pachytene stage. BMC Genomics 2016; 17:294. [PMID: 27094866 PMCID: PMC4837615 DOI: 10.1186/s12864-016-2618-1] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 04/13/2016] [Indexed: 12/03/2022] Open
Abstract
Background Spermatogenesis is a complex differentiation process that involves the successive and simultaneous execution of three different gene expression programs: mitotic proliferation of spermatogonia, meiosis, and spermiogenesis. Testicular cell heterogeneity has hindered its molecular analyses. Moreover, the characterization of short, poorly represented cell stages such as initial meiotic prophase ones (leptotene and zygotene) has remained elusive, despite their crucial importance for understanding the fundamentals of meiosis. Results We have developed a flow cytometry-based approach for obtaining highly pure stage-specific spermatogenic cell populations, including early meiotic prophase. Here we combined this methodology with next generation sequencing, which enabled the analysis of meiotic and postmeiotic gene expression signatures in mouse with unprecedented reliability. Interestingly, we found that a considerable number of genes involved in early as well as late meiotic processes are already on at early meiotic prophase, with a high proportion of them being expressed only for the short time lapse of lepto-zygotene stages. Besides, we observed a massive change in gene expression patterns during medium meiotic prophase (pachytene) when mostly genes related to spermiogenesis and sperm function are already turned on. This indicates that the transcriptional switch from meiosis to post-meiosis takes place very early, during meiotic prophase, thus disclosing a higher incidence of post-transcriptional regulation in spermatogenesis than previously reported. Moreover, we found that a good proportion of the differential gene expression in spermiogenesis corresponds to up-regulation of genes whose expression starts earlier, at pachytene stage; this includes transition protein-and protamine-coding genes, which have long been claimed to switch on during spermiogenesis. In addition, our results afford new insights concerning X chromosome meiotic inactivation and reactivation. Conclusions This work provides for the first time an overview of the time course for the massive onset and turning off of the meiotic and spermiogenic genetic programs. Importantly, our data represent a highly reliable information set about gene expression in pure testicular cell populations including early meiotic prophase, for further data mining towards the elucidation of the molecular bases of male reproduction in mammals. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2618-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Irene da Cruz
- Department of Genomics, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Av. Italia 3318, 11,600, Montevideo, Uruguay.,Department of Molecular Biology, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Av. Italia 3318, 11,600, Montevideo, Uruguay
| | - Rosana Rodríguez-Casuriaga
- Department of Molecular Biology, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Av. Italia 3318, 11,600, Montevideo, Uruguay
| | | | - Joaquina Farías
- Department of Proteins and Nucleic Acids, IIBCE, Montevideo, Uruguay
| | - Gianni Curti
- Department of Molecular Biology, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Av. Italia 3318, 11,600, Montevideo, Uruguay
| | - Carlos A Capoano
- Department of Molecular Biology, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Av. Italia 3318, 11,600, Montevideo, Uruguay
| | - Gustavo A Folle
- Flow Cytometry and Cell Sorting Core, IIBCE, Montevideo, Uruguay.,Department of Genetics, IIBCE, Montevideo, Uruguay
| | - Ricardo Benavente
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, D-97074, Würzburg, Germany
| | - José Roberto Sotelo-Silveira
- Department of Genomics, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Av. Italia 3318, 11,600, Montevideo, Uruguay. .,Department of Cell and Molecular Biology, Facultad de Ciencias, Universidad de la República (UDELAR), 11,400, Montevideo, Uruguay.
| | - Adriana Geisinger
- Department of Molecular Biology, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Av. Italia 3318, 11,600, Montevideo, Uruguay. .,Biochemistry-Molecular Biology, Facultad de Ciencias, UDELAR, Montevideo, Uruguay.
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13
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Edwards N, Farookhi R, Clarke HJ. Identification of a β-galactosidase transgene that provides a live-cell marker of transcriptional activity in growing oocytes and embryos. Mol Hum Reprod 2015; 21:583-93. [PMID: 25882542 PMCID: PMC4487448 DOI: 10.1093/molehr/gav020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 03/27/2015] [Accepted: 04/09/2015] [Indexed: 01/14/2023] Open
Abstract
Identifying the events and molecular mechanisms that regulate oocyte growth has emerged as a key objective of research in human fertility, fuelled by evidence from human and animal studies indicating that disease and environmental factors can act on oocytes to affect the health of the resulting individual and by efforts to grow oocytes in vitro to enable fertility preservation of cancer survivors. Techniques that monitor the development of growing oocytes would be valuable tools to assess the progression of growth under different conditions. Most methods used to assess oocytes grown in vitro are indirect, however, relying on characteristics of the somatic compartment of the follicle, or compromise the oocyte, preventing its subsequent culture or fertilization. We investigated the utility of T-cell factor/lymphoid enhancer-binding factor (TCF/Lef)-LacZ transgene expression as a predictor of global transcriptional activity in oocytes and early embryos. Using a fluorescent β-galactosidase substrate combined with live-cell imaging, we show that TCF/Lef-LacZ transgene expression is detectable in growing oocytes, lost in fully grown oocytes and resumes in late two-cell embryos. Transgene expression is likely regulated by a Wnt-independent mechanism. Using chromatin analysis, LacZ expression and methods to monitor and inhibit transcription, we show that TCF/Lef-LacZ expression mirrors transcriptional activity in oocytes and preimplantation embryos. Oocytes and preimplantation embryos that undergo live-cell imaging for TCF/Lef-LacZ expression are able to continue development in vitro. TCF/Lef-LacZ reporter expression in living oocytes and early embryos is thus a sensitive and faithful marker of transcriptional activity that can be used to monitor and optimize conditions for oocyte growth.
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Affiliation(s)
- Nicole Edwards
- Department of Obstetrics and Gynecology, McGill University, Montreal, QC, Canada Department of Physiology, McGill University, Montreal, QC, Canada Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Riaz Farookhi
- Department of Obstetrics and Gynecology, McGill University, Montreal, QC, Canada Department of Physiology, McGill University, Montreal, QC, Canada Research Institute of the McGill University Health Centre, Montreal, QC, Canada Department of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Hugh J Clarke
- Department of Obstetrics and Gynecology, McGill University, Montreal, QC, Canada Research Institute of the McGill University Health Centre, Montreal, QC, Canada Department of Experimental Medicine, McGill University, Montreal, QC, Canada Department of Biology, McGill University, Montreal, QC, Canada
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14
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Ramos-Ibeas P, Pericuesta E, Fernández-González R, Gutiérrez-Adán A, Ramírez MÁ. Characterisation of the deleted in azoospermia like (Dazl)-green fluorescent protein mouse model generated by a two-step embryonic stem cell-based strategy to identify pluripotent and germ cells. Reprod Fertil Dev 2015; 28:RD14253. [PMID: 25942058 DOI: 10.1071/rd14253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 04/04/2015] [Indexed: 02/28/2024] Open
Abstract
The deleted in azoospermia like (Dazl) gene is preferentially expressed in germ cells; however, recent studies indicate that it may have pluripotency-related functions. We generated Dazl-green fluorescent protein (GFP) transgenic mice and assayed the ability of Dazl-driven GFP to mark preimplantation embryo development, fetal, neonatal and adult tissues, and in vitro differentiation from embryonic stem cells (ESCs) to embryoid bodies (EBs) and to primordial germ cell (PGC)-like cells. The Dazl-GFP mice were generated by a two-step ESC-based strategy, which enabled primary and secondary screening of stably transfected clones before embryo injection. During preimplantation embryo stages, GFP was detected from the zygote to blastocyst stage. At Embryonic Day (E) 12.5, GFP was expressed in gonadal ridges and in neonatal gonads of both sexes. In adult mice, GFP expression was found during spermatogenesis from spermatogonia to elongating spermatids and in the cytoplasm of oocytes. However, GFP mRNA was also detected in other tissues harbouring multipotent cells, such as the intestine and bone marrow. Fluorescence was maintained along in vitro Dazl-GFP ESC differentiation to EBs, and in PGC-like cells. In addition to its largely known function in germ cell development, Dazl could have an additional role in pluripotency, supporting these transgenic mice as a valuable tool for the prospective identification of stem cells from several tissues.
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15
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Zeng F, Huang F, Guo J, Hu X, Liu C, Wang H. Emerging methods to generate artificial germ cells from stem cells. Biol Reprod 2015; 92:89. [PMID: 25715792 DOI: 10.1095/biolreprod.114.124800] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 02/16/2015] [Indexed: 12/29/2022] Open
Abstract
Germ cells are responsible for the transmission of genetic and epigenetic information across generations. At present, the number of infertile couples is increasing worldwide; these infertility problems can be traced to environmental pollutions, infectious diseases, cancer, psychological or work-related stress, and other factors, such as lifestyle and genetics. Notably, lack of germ cells and germ cell loss present real obstacles in infertility treatment. Recent research aimed at producing gametes through artificial germ cell generation from stem cells may offer great hope for affected couples to treat infertility in the future. Therefore, this rapidly emerging area of artificial germ cell generation from nongermline cells has gained considerable attention from basic and clinical research in the fields of stem cell biology, developmental biology, and reproductive biology. Here, we review the state of the art in artificial germ cell generation.
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Affiliation(s)
- Fanhui Zeng
- The Central Hospital of Enshi Tujia and Miao Autonomous Prefecture, Enshi, China
| | - Fajun Huang
- School of Medical Science, Hubei University for Nationalities, Enshi, China
| | - Jingjing Guo
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, China
| | - Xingchang Hu
- College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, China
| | - Changbai Liu
- The Institute of Molecular Biology, China Three Gorges University, Yichang, China
| | - Hu Wang
- Medical School, China Three Gorges University, Yichang, China
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16
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Chen HH, Welling M, Bloch DB, Muñoz J, Mientjes E, Chen X, Tramp C, Wu J, Yabuuchi A, Chou YF, Buecker C, Krainer A, Willemsen R, Heck AJ, Geijsen N. DAZL limits pluripotency, differentiation, and apoptosis in developing primordial germ cells. Stem Cell Reports 2014; 3:892-904. [PMID: 25418731 PMCID: PMC4235140 DOI: 10.1016/j.stemcr.2014.09.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 09/03/2014] [Accepted: 09/03/2014] [Indexed: 01/27/2023] Open
Abstract
The scarcity of primordial germ cells (PGCs) in the developing mammalian embryo hampers robust biochemical analysis of the processes that underlie early germ cell formation. Here, we demonstrate that DAZL, a germ cell-specific RNA binding protein, is a robust PGC marker during in vitro germ cell development. Using Dazl-GFP reporter ESCs, we demonstrate that DAZL plays a central role in a large mRNA/protein interactive network that blocks the translation of core pluripotency factors, including Sox2 and Sall4, as well as of Suz12, a polycomb family member required for differentiation of pluripotent cells. Thus, DAZL limits both pluripotency and somatic differentiation in nascent PGCs. In addition, we observed that DAZL associates with mRNAs of key Caspases and similarly inhibits their translation. This elegant fail-safe mechanism ensures that, whereas loss of DAZL results in prolonged expression of pluripotency factors, teratoma formation is avoided due to the concomitant activation of the apoptotic cascade.
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Affiliation(s)
- Hsu-Hsin Chen
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Maaike Welling
- Hubrecht Institute and University Medical Center, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - Donald B Bloch
- Department of Rheumatology, Allergy and Immunology, Department of Rheumatology, Center for Immunology and Inflammatory Diseases, Boston, MA 02114, USA
| | - Javier Muñoz
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences and Netherlands Proteomics Center, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Edwin Mientjes
- Department of Clinical Genetics, Erasmus Medical Center, 3000 CA Rotterdam, the Netherlands
| | - Xinjie Chen
- Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical College, Guangzhou 510150, PR China
| | - Cody Tramp
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Jie Wu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Akiko Yabuuchi
- Division of Pediatric Hematology/Oncology, Children's Hospital Boston and Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Yu-Fen Chou
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Christa Buecker
- Hubrecht Institute and University Medical Center, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - Adrian Krainer
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Rob Willemsen
- Department of Clinical Genetics, Erasmus Medical Center, 3000 CA Rotterdam, the Netherlands
| | - Albert J Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences and Netherlands Proteomics Center, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Niels Geijsen
- Hubrecht Institute and University Medical Center, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands; Department of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, the Netherlands.
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17
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Smorag L, Xu X, Engel W, Pantakani DVK. The roles of DAZL in RNA biology and development. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 5:527-35. [PMID: 24715697 DOI: 10.1002/wrna.1228] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 02/17/2014] [Accepted: 02/18/2014] [Indexed: 01/20/2023]
Abstract
RNA-binding proteins play an important role in the regulation of gene expression by modulating translation and localization of specific messenger RNAs (mRNAs) during early development and gametogenesis. The DAZ (Deleted in Azoospermia) family of proteins, which includes DAZ, DAZL, and BOULE, are germ cell-specific RNA-binding proteins that are implicated in translational regulation of several transcripts. Of particular importance is DAZL, which is present in vertebrates and arose from the duplication of the ancestral BOULE during evolution. Identification of DAZL target mRNAs and characterization of the RNA-binding sequence through in vitro binding assays and crystallographic studies revealed that DAZL binds to GUU triplets in the 3' untranslated region of target mRNAs. Although there is compelling evidence for the role of DAZL in translation stimulation of target mRNAs, recent studies indicate that DAZL can also function in translational repression and transport of specific mRNAs. Furthermore, apart from the well-characterized function of DAZL in gametogenesis, recent data suggest its role in early embryonic development and differentiation of pluripotent stem cells toward functional gametes. In light of the mounting evidence for the role of DAZL in various cellular and developmental processes, we summarize the currently characterized biological functions of DAZL in RNA biology and development.
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Affiliation(s)
- Lukasz Smorag
- Institute of Human Genetics, University of Goettingen, Goettingen, Germany
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18
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Werler S, Demond H, Damm OS, Ehmcke J, Middendorff R, Gromoll J, Wistuba J. Germ cell loss is associated with fading Lin28a expression in a mouse model for Klinefelter's syndrome. Reproduction 2014; 147:253-64. [DOI: 10.1530/rep-13-0608] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Klinefelter's syndrome is a male sex-chromosomal disorder (47,XXY), causing hypogonadism, cognitive and metabolic deficits. The majority of patients are infertile due to complete germ cell loss after puberty. As the depletion occurs during development, the possibilities to study the underlying causes in humans are limited. In this study, we used the 41,XXY* mouse model to characterise the germ line postnatally. We examined marker expression of testicular cells focusing on the spermatogonial stem cells (SSCs) and found that the number of germ cells was approximately reduced fivefold at day 1pp in the 41,XXY* mice, indicating the loss to start prenatally. Concurrently, immunohistochemical SSC markers LIN28A and PGP9.5 also showed decreased expression on day 1pp in the 41,XXY* mice (48.5 and 38.9% of all germ cells were positive), which dropped to 7.8 and 7.3% on 3dpp, and were no longer detectable on days 5 and 10pp respectively. The differences in PCNA-positive proliferating cells in XY* and XXY* mice dramatically increased towards day 10pp. The mRNA expression of the germ cell markers Lin28a (Lin28), Pou5f1 (Oct4), Utf1, Ddx4 (Vasa), Dazl, and Fapb1 (Sycp3) was reduced and the Lin28a regulating miRNAs were deregulated in the 41,XXY* mice. We suggest a model for the course of germ cell loss starting during the intrauterine period. Neonatally, SSC marker expression by the already lowered number of spermatogonia is reduced and continues fading during the first postnatal week, indicating the surviving cells of the SSC population to be disturbed in their stem cell characteristics. Subsequently, the entire germ line is then generally lost when entering meiosis.
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Toda K, Hayashi Y, Yamashita A, Okabe M, Ono M, Saibara T. Aromatase-null mice expressing enhanced green fluorescent protein in germ cells provide a model system to assess estrogen-dependent ovulatory responses. Transgenic Res 2013; 23:293-302. [PMID: 24272335 DOI: 10.1007/s11248-013-9771-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 11/15/2013] [Indexed: 12/24/2022]
Abstract
Enhanced green fluorescent protein (EGFP) has provided us with valuable approaches for tracking living cells. We established a novel line of transgenic mice, which express EGFP in the testis and ovary. Histological analysis demonstrated that spermatids in the testis and oocytes in ovarian follicles beyond preantral stages were positive for EGFP. By exploiting these features, we evaluated ovulatory responses of aromatase-gene (Cyp19a) knockout mouse expressing the EGFP transgene, which is totally anovulatory due to 17β-estradiol (E2) deficiency. Ovulation in the knockout mice was induced by sequential injections of E2 on days 1, 4 and 5, pregnant mare serum gonadotropin on day 4 and human chorionic gonadotropin on day 6. Fluorescent oocytes were readily detectable at 15 h after the last gonadotropin injection in the oviduct under a fluorescence stereomicroscope, even when only one oocyte was present. However, when E2 supplementation on day 4 or day 5 in the regimen was omitted, no ovulated oocytes were detected, indicating that exogenous E2 supplementation at the time of gonadotropin stimulation is necessary to induce ovulation in aromatase-gene knockout mice. Our results further demonstrated that the current mouse line can provide an alternative tool to study germ cell biology, including oogenesis, ovulation and senescence.
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Affiliation(s)
- Katsumi Toda
- Department of Biochemistry, School of Medicine, Kochi University, Nankoku, Kochi, 783-8505, Japan,
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20
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Ramos-Ibeas P, Pericuesta E, Fernández-González R, Ramírez MA, Gutierrez-Adan A. Most regions of mouse epididymis are able to phagocytose immature germ cells. Reproduction 2013; 146:481-9. [DOI: 10.1530/rep-13-0145] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The role of the epididymis as a quality control organ in preventing infertile gametes entering the ejaculate has been extensively explored, and it has been suggested that a specific region of mammalian epididymis is able to phagocytose abnormal germ cells. This study examines whether the epithelium of certain zones of the mouse epididymis can act as a selection barrier by removing immature germ cells from the lumen by phagocytosis. To detect the presence of immature germ cells in the epididymis, we generated transgenic mice expressing enhanced green fluorescent protein under the deleted in azoospermia-like (mDazl) promoter to easily identify immature germ cells under fluorescence microscopy. Using this technique, we observed that during the first stage of spermatogenesis in prepuberal mice, a wave of immature germ cells is released into the epididymis and that the immature epididymis is not able to react to this abnormal situation. By contrast, when immature germ cells were artificially released into the epididymis in adult mice, a phagocytic response was observed. Phagosomes appeared inside principal cells of the epididymal epithelium and were observed to contain immature germ cells at different degradation stages in different zones of the epididymis, following the main wave of immature germ cells. In this paper, we describe how the epididymal epithelium controls sperm quality by clearing immature germ cells in response to their artificially induced massive shedding into the epididymal lumen. Our observations indicate that this phenomenon is not restricted to a given epididymis region and that phagocytic capacity is gradually acquired during epididymal development.
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21
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Imamura M, Hikabe O, Lin ZYC, Okano H. Generation of germ cells in vitro in the era of induced pluripotent stem cells. Mol Reprod Dev 2013; 81:2-19. [PMID: 23996404 DOI: 10.1002/mrd.22259] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Accepted: 08/21/2013] [Indexed: 01/15/2023]
Abstract
Induced pluripotent stem cells (iPSCs) are stem cells that can be artificially generated via "cellular reprogramming" using gene transduction in somatic cells. iPSCs have enormous potential in stem-cell biology as they can give rise to numerous cell lineages, including the three germ layers. An evaluation of germ-line competency by blastocyst injection or tetraploid complementation, however, is critical for determining the developmental potential of mouse iPSCs towards germ cells. Recent studies have demonstrated that primordial germ cells obtained by the in vitro differentiation of iPSCs produce functional gametes as well as healthy offspring. These findings illustrate not only that iPSCs are developmentally similar to embryonic stem cells (ESCs), but also that somatic cells from adult tissues can produce gametes in vitro, that is, if they are reprogrammed into iPSCs. In this review, we discuss past and recent advances in the in vitro differentiation of germ cells using pluripotent stem cells, with an emphasis on ESCs and iPSCs. While this field of research is still at a stage of infancy, it holds great promises for investigating the mechanisms of germ-cell development, especially in humans, and for advancing reproductive and developmental engineering technologies in the future.
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Affiliation(s)
- Masanori Imamura
- Department of Physiology, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan
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22
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Implication of DNA demethylation and bivalent histone modification for selective gene regulation in mouse primordial germ cells. PLoS One 2012; 7:e46036. [PMID: 23029374 PMCID: PMC3461056 DOI: 10.1371/journal.pone.0046036] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 08/28/2012] [Indexed: 01/15/2023] Open
Abstract
Primordial germ cells (PGCs) sequentially induce specific genes required for their development. We focused on epigenetic changes that regulate PGC-specific gene expression. mil-1, Blimp1, and Stella are preferentially expressed in PGCs, and their expression is upregulated during PGC differentiation. Here, we first determined DNA methylation status of mil-1, Blimp1, and Stella regulatory regions in epiblast and in PGCs, and found that they were hypomethylated in differentiating PGCs after E9.0, in which those genes were highly expressed. We used siRNA to inhibit a maintenance DNA methyltransferase, Dnmt1, in embryonic stem (ES) cells and found that the flanking regions of all three genes became hypomethylated and that expression of each gene increased 1.5- to 3-fold. In addition, we also found 1.5- to 5-fold increase of the PGC genes in the PGCLCs (PGC-like cells) induced form ES cells by knockdown of Dnmt1. We also obtained evidence showing that methylation of the regulatory region of mil-1 resulted in 2.5-fold decrease in expression in a reporter assay. Together, these results suggested that DNA demethylation does not play a major role on initial activation of the PGC genes in the nascent PGCs but contributed to enhancement of their expression in PGCs after E9.0. However, we also found that repression of representative somatic genes, Hoxa1 and Hoxb1, and a tissue-specific gene, Gfap, in PGCs was not dependent on DNA methylation; their flanking regions were hypomethylated, but their expression was not observed in PGCs at E13.5. Their promoter regions showed the bivalent histone modification in PGCs, that may be involved in repression of their expression. Our results indicated that epigenetic status of PGC genes and of somatic genes in PGCs were distinct, and suggested contribution of epigenetic mechanisms in regulation of the expression of a specific gene set in PGCs.
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Teng YN, Chang YP, Tseng JT, Kuo PH, Lee IW, Lee MS, Kuo PL. A single-nucleotide polymorphism of the DAZL gene promoter confers susceptibility to spermatogenic failure in the Taiwanese Han. Hum Reprod 2012; 27:2857-65. [PMID: 22752612 DOI: 10.1093/humrep/des227] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Deleted in AZoospermia-like (DAZL) is an autosomal homologue of Y chromosome-linked DAZ gene located on chromosome 3p24. DAZL is only expressed in the gonads and is critical to germ cell development in different species. However, the regulation of DAZL has not been explored. METHODS Reporter assays, electrophoretic mobility shift assays, supershift assays and bisulfate sequencing were used to identify the core promoter region of DAZL. Sequence analysis was used to identify single-nucleotide polymorphisms (SNPs) in the promoter region. A total of 337 infertile men with abnormal semen parameters and 203 fertile men with normal semen parameters were subjected to sequence analysis of the DAZL promoter region. RESULTS The DAZL gene core promoter is located 1 kb upstream of the transcription start site. Three SNPs (-792G>A, -669A>C and -309T>C) were identified in our population. Of these three SNPs, -792G>A was more prevalent in the infertile men (P= 0.0005). Quantitative analysis revealed that genotypes of -792G>A had effects on sperm concentration (P= 0.0025) and motility (P= 1.5 × 10(-7)). The G to A substitution was associated with decreased binding of the nuclear respiratory factor-1 (NRF-1) to the promoter region and decreased reporter gene activity. CONCLUSION We have identified the core promoter of the human DAZL gene. We also provide preliminary evidence for the role of a novel SNP of the DAZL gene promoter in human spermatogenic failure.
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Affiliation(s)
- Yeng-Ni Teng
- Department of Biological Sciences and Technology, National University of Tainan, Tainan, Taiwan
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24
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Hou Y, Yuan J, Zhou X, Fu X, Cheng H, Zhou R. DNA demethylation and USF regulate the meiosis-specific expression of the mouse Miwi. PLoS Genet 2012; 8:e1002716. [PMID: 22661915 PMCID: PMC3355075 DOI: 10.1371/journal.pgen.1002716] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 03/30/2012] [Indexed: 01/01/2023] Open
Abstract
Miwi, a member of the Argonaute family, is required for initiating spermiogenesis; however, the mechanisms that regulate the expression of the Miwi gene remain unknown. By mutation analysis and transgenic models, we identified a 303 bp proximal promoter region of the mouse Miwi gene, which controls specific expression from midpachytene spermatocytes to round spermatids during meiosis. We characterized the binding sites of transcription factors NF-Y (Nuclear Factor Y) and USF (Upstream Stimulatory Factor) within the core promoter and found that both factors specifically bind to and activate the Miwi promoter. Methylation profiling of three CpG islands within the proximal promoter reveals a markedly inverse correlation between the methylation status of the CpG islands and germ cell type–specific expression of Miwi. CpG methylation at the USF–binding site within the E2 box in the promoter inhibits the binding of USF. Transgenic Miwi-EGFP and endogenous Miwi reveal a subcellular co-localization pattern in the germ cells of the Miwi-EGFP transgenic mouse. Furthermore, the DNA methylation profile of the Miwi promoter–driven transgene is consistent with that of the endogenous Miwi promoter, indicating that Miwi transgene is epigenetically modified through methylation in vivo to ensure its spatio-temporal expression. Our findings suggest that USF controls Miwi expression from midpachytene spermatocytes to round spermatids through methylation-mediated regulation. This work identifies an epigenetic regulation mechanism for the spatio-temporal expression of mouse Miwi during spermatogenesis. Germ cell differentiation is a key process in the formation of functional spermatozoa. Despite the wealth of information about gene expression patterns and regulations important for this process, it is not clear how spatio-temporal expression of the key factor Miwi during spermatogenesis is controlled. We have characterized the functional promoter of the mouse Miwi gene. Transgenic mice harboring EGFP under the Miwi core promoter containing just the functional CCAAT box and E2 box were generated and demonstrated that it can direct germ cell–specific expression. We further identified the transcription factors NF-Y and USF1/2 as activators of Miwi gene expression, through their binding to the CCAAT box and E-box/E2 site of the Miwi promoter, respectively. A CpG dinucleotide just located within the USF binding site is responsible for mediating methylation-dependent silencing of the Miwi gene. Our findings provide new insight into an epigenetic regulation mechanism for the spatio-temporal expression of the mouse Miwi during spermatogenesis.
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Affiliation(s)
| | | | | | | | - Hanhua Cheng
- Department of Genetics, College of Life Sciences, Wuhan University, Wuhan, China
- * E-mail: (HC); (RZ)
| | - Rongjia Zhou
- Department of Genetics, College of Life Sciences, Wuhan University, Wuhan, China
- * E-mail: (HC); (RZ)
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25
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Bernstein HS, Hyun WC. Strategies for enrichment and selection of stem cell-derived tissue precursors. Stem Cell Res Ther 2012; 3:17. [PMID: 22575029 PMCID: PMC3392764 DOI: 10.1186/scrt108] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Human embryonic stem cells have the capacity for self-renewal and pluripotency and thus are a primary candidate for tissue engineering and regenerative therapies. These cells also provide an opportunity to study the development of human tissues ex vivo. To date, numerous human embryonic stem cell lines have been derived and characterized. In this review, we will detail the strategies used to direct tissue-specific differentiation of embryonic stem cells. We also will discuss how these strategies have produced new sources of tissue-specific progenitor cells. Finally, we will describe the next generation of methods being developed to identify and select stem cell-derived tissue precursors for experimental study and clinical use.
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Affiliation(s)
- Harold S Bernstein
- Department of Pediatrics (Cardiology), University of California San Francisco, San Francisco, CA 94143-1346, USA.
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26
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Garcia T, Hofmann MC. Isolation of undifferentiated and early differentiating type A spermatogonia from Pou5f1-GFP reporter mice. Methods Mol Biol 2012; 825:31-44. [PMID: 22144234 PMCID: PMC3314309 DOI: 10.1007/978-1-61779-436-0_3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Limited understanding of the mechanisms underlying self-renewal and differentiation of spermatogonial stem cells hampers our ability to develop new therapeutic and contraceptive approaches. Mouse models of spermatogonial stem cell development are key to developing new insights into the biology of both the normal and diseased testis. Advances in transgenic reporter mice have enabled the isolation, molecular characterization, and functional analysis of mouse Type A spermatogonia subpopulations from the normal testis, including populations enriched for spermatogonial stem cells. Application of these reporters both to the normal testis and to gene-deficient and over-expression models will promote a better understanding of the earliest steps of spermatogenesis, and the role of spermatogonial stem cells in germ cell tumor.
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Affiliation(s)
- Thomas Garcia
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA
| | - Marie-Claude Hofmann
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA
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Single cell analysis facilitates staging of Blimp1-dependent primordial germ cells derived from mouse embryonic stem cells. PLoS One 2011; 6:e28960. [PMID: 22194959 PMCID: PMC3240638 DOI: 10.1371/journal.pone.0028960] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 11/17/2011] [Indexed: 12/15/2022] Open
Abstract
The cell intrinsic programming that regulates mammalian primordial germ cell (PGC) development in the pre-gonadal stage is challenging to investigate. To overcome this we created a transgene-free method for generating PGCs in vitro (iPGCs) from mouse embryonic stem cells (ESCs). Using labeling for SSEA1 and cKit, two cell surface molecules used previously to isolate presumptive iPGCs, we show that not all SSEA1+/cKit+ double positive cells exhibit a PGC identity. Instead, we determined that selecting for cKitbright cells within the SSEA1+ fraction significantly enriches for the putative iPGC population. Single cell analysis comparing SSEA1+/cKitbright iPGCs to ESCs and embryonic PGCs demonstrates that 97% of single iPGCs co-express PGC signature genes Blimp1, Stella, Dnd1, Prdm14 and Dazl at similar levels to e9.5–10.5 PGCs, whereas 90% of single mouse ESC do not co-express PGC signature genes. For the 10% of ESCs that co-express PGC signature genes, the levels are significantly lower than iPGCs. Microarray analysis shows that iPGCs are transcriptionally distinct from ESCs and repress gene ontology groups associated with mesoderm and heart development. At the level of chromatin, iPGCs contain 5-methyl cytosine bases in their DNA at imprinted and non-imprinted loci, and are enriched in histone H3 lysine 27 trimethylation, yet do not have detectable levels of Mvh protein, consistent with a Blimp1-positive pre-gonadal PGC identity. In order to determine whether iPGC formation is dependent upon Blimp1, we generated Blimp1 null ESCs and found that loss of Blimp1 significantly depletes SSEA1/cKitbright iPGCs. Taken together, the generation of Blimp1-positive iPGCs from ESCs constitutes a robust model for examining cell-intrinsic regulation of PGCs during the Blimp1-positive stage of development.
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Vangompel MJW, Xu EY. The roles of the DAZ family in spermatogenesis: More than just translation? SPERMATOGENESIS 2011; 1:36-46. [PMID: 22523742 PMCID: PMC3329454 DOI: 10.4161/spmg.1.1.14659] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The DAZ family of genes are important fertility factors in animals, including humans. The family consists of Y-linked DAZ, and autosomal homologs Boule and Dazl. All three genes encode RNA-binding proteins that are nearly exclusively expressed in germ cells. The DAZ family is highly conserved, with ancestral Boule present in sea anemones through humans, Dazl conserved among vertebrates, and DAZ present only in higher primates. Here we review studies on DAZ family genes from multiple organisms, and summarize the common features of each DAZ gene and their roles during spermatogenesis in animals. DAZ family proteins are thought to activate the translation of RNA targets, but recent work has uncovered additional functions. Boule, Dazl, and DAZ likely function through similar mechanisms, and we present known functions of the DAZ family in spermatogenesis, and discuss possible mechanisms in addition to translation activation.
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Affiliation(s)
- Michael J W Vangompel
- Department of Obstetrics and Gynecology; Division of Reproductive Biology Research and Center for Genetic Medicine; Northwestern University; Chicago, IL USA
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Clark AT. Egg-Citing Advances in Generating Primordial Germ Cells in the Laboratory. Biol Reprod 2010; 82:233-4. [DOI: 10.1095/biolreprod.109.082388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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