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Abstract
Primordial germ cells (PGCs) form early in embryo development and are crucial precursors to functioning gamete cells. Considerable research has focussed on identifying the transcriptional characteristics and signalling pathway requirements that confer PGC specification and development, enabling the derivation of PGC-like cells (PGCLCs) in vitro using specific signalling cocktails. However, full maturation to germ cells still relies on co-culture with supporting cell types, implicating an additional requirement for cellular- and tissue-level regulation. Here, we discuss the experimental evidence that highlights the nature of intercellular interactions between PGCs and neighbouring cell populations during mouse PGC development. We posit that the role that tissue interactions play on PGCs is not limited solely to signalling-based induction but extends to coordination of development by robust regulation of the proportions and position of the cells and tissues within the embryo, which is crucial for functional germ cell maturation. Such tissue co-development provides a dynamic, contextual niche for PGC development. We argue that there is evidence for a clear role for inter-tissue dependence of mouse PGCs, with potential implications for generating mammalian PGCLCs in vitro.
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Affiliation(s)
- Christopher B Cooke
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK.,Abcam Plc, Discovery Drive, Cambridge Biomedical Campus, Cambridge, CB2 0AX, UK.,The Francis Crick Institute, 1 Midland Road, Somers Town, London, NW1 1AT, UK
| | - Naomi Moris
- The Francis Crick Institute, 1 Midland Road, Somers Town, London, NW1 1AT, UK
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Dygai AM, Chaikovskii AV, Zhdanov VV, Zyuz’kov GN, Stavrova LA, Udut VV, Miroshnichenko LA, Simanina EV, Borovskaya TG, Poluektova ME. Responses of Spermatogenous Tissue and Mechanisms of Their Development Upon Cytostatic Exposure. Bull Exp Biol Med 2015; 159:743-6. [DOI: 10.1007/s10517-015-3064-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Indexed: 11/28/2022]
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Hu YC, Nicholls PK, Soh YQS, Daniele JR, Junker JP, van Oudenaarden A, Page DC. Licensing of primordial germ cells for gametogenesis depends on genital ridge signaling. PLoS Genet 2015; 11:e1005019. [PMID: 25739037 PMCID: PMC4349450 DOI: 10.1371/journal.pgen.1005019] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 01/22/2015] [Indexed: 01/07/2023] Open
Abstract
In mouse embryos at mid-gestation, primordial germ cells (PGCs) undergo licensing to become gametogenesis-competent cells (GCCs), gaining the capacity for meiotic initiation and sexual differentiation. GCCs then initiate either oogenesis or spermatogenesis in response to gonadal cues. Germ cell licensing has been considered to be a cell-autonomous and gonad-independent event, based on observations that some PGCs, having migrated not to the gonad but to the adrenal gland, nonetheless enter meiosis in a time frame parallel to ovarian germ cells -- and do so regardless of the sex of the embryo. Here we test the hypothesis that germ cell licensing is cell-autonomous by examining the fate of PGCs in Gata4 conditional mutant (Gata4 cKO) mouse embryos. Gata4, which is expressed only in somatic cells, is known to be required for genital ridge initiation. PGCs in Gata4 cKO mutants migrated to the area where the genital ridge, the precursor of the gonad, would ordinarily be formed. However, these germ cells did not undergo licensing and instead retained characteristics of PGCs. Our results indicate that licensing is not purely cell-autonomous but is induced by the somatic genital ridge. During embryonic development, stem cell-like primordial germ cells travel across the developing embryo to the genital ridge, which gives rise to the gonad. Around the time of their arrival, the primordial germ cells gain the capacity to undertake sexual specialization and meiosis—a process called germ cell licensing. Based on the observation that meiosis and sexual differentiation can occur when primordial germ cells stray into the area of the adrenal gland, the primordial germ cell has been thought to be responsible for its own licensing. We tested this notion by examining the licensing process in mutant mouse embryos that did not form a genital ridge. We discovered that in the absence of the genital ridge, primordial germ cells migrate across the developing embryo properly, but instead of undergoing licensing, these cells retain their primordial germ cell characteristics. We conclude that licensing of embryonic primordial germ cells for gametogenesis is dependent on signaling from the genital ridge.
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Affiliation(s)
- Yueh-Chiang Hu
- Whitehead Institute, Cambridge, Massachusetts, United States of America
| | - Peter K. Nicholls
- Whitehead Institute, Cambridge, Massachusetts, United States of America
| | - Y. Q. Shirleen Soh
- Whitehead Institute, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Joseph R. Daniele
- Whitehead Institute, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Jan Philipp Junker
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Hubrecht Institute—KNAW (Royal Netherlands Academy of Arts and Sciences) and University Medical Center Utrecht, Utrecht, Netherlands
| | - Alexander van Oudenaarden
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Hubrecht Institute—KNAW (Royal Netherlands Academy of Arts and Sciences) and University Medical Center Utrecht, Utrecht, Netherlands
| | - David C. Page
- Whitehead Institute, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Howard Hughes Medical Institute, Whitehead Institute, Cambridge, Massachusetts, United States of America
- * E-mail:
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Mirzapour T, Movahedin M, Tengku Ibrahim TA, Haron AW, Nowroozi MR. Evaluation of the effects of cryopreservation on viability, proliferation and colony formation of human spermatogonial stem cells in vitro culture. Andrologia 2012; 45:26-34. [PMID: 22621173 DOI: 10.1111/j.1439-0272.2012.01302.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2012] [Indexed: 01/15/2023] Open
Abstract
Proliferation of spermatogonial stem cells (SSCs) in vitro system is very important. It can enhance SSCs numbers for success of transplantation and treatment of infertility in cancer patients. In this study, testicular cells that obtained from azoospermia patients (n=8) by enzymatic digestion were cryopreserved at the beginning and after 2 weeks of culture. Then, frozen-thawed SSCs were co-cultured on fresh Sertoli cells (experimental group 1), and frozen-thawed Sertoli cells (experimental group 2) for another 3 weeks. In control group, fresh SSCs were co-cultured on fresh Sertoli cells. Viability rate after enzymatic digestion was 93.4%±5.0. Frozen-thawed testicular cells after 2 weeks of culture had a significantly (P<0.05) higher percentage of living cells compared to frozen-thawed testicular cells at the beginning of culture (59.2±7.05 and 46.3±8.40 respectively). The number of colonies in the experimental group 1 was significantly higher than experimental group 2 (19.6±2.8 and 8.33±1.5, respectively, P<0.05). The diameter of the colonies in the experimental group 1 was significantly higher than control and experimental group 2 (P<0.05) after 3 weeks of culture (269.7±52.1, 204.34±24.1 and 112.52±23.5 μm, respectively). Cryopreservation technique will raise the possibility of banking SSCs for men who have a cancer-related illness and waiting for radiotherapy and/or chemotherapy.
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Affiliation(s)
- T Mirzapour
- Department of Biology, University of Mohaghegh Ardabili, Ardabil, Iran.
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Nowroozi MR, Ahmadi H, Rafiian S, Mirzapour T, Movahedin M. In vitro colonization of human spermatogonia stem cells: effect of patient's clinical characteristics and testicular histologic findings. Urology 2011; 78:1075-81. [PMID: 21908023 DOI: 10.1016/j.urology.2011.06.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2010] [Revised: 06/05/2011] [Accepted: 06/14/2011] [Indexed: 12/25/2022]
Abstract
OBJECTIVE To evaluate the effect of the demographic/clinical characteristics of patients and testicular histologic findings on the in vitro colonization of human spermatogonial stem cells (SSCs). In vitro isolation and proliferation of human SSCs has emerged as a suitable method for the enrichment of spermatogonia germ cells. METHODS SSCs were isolated from the testicular biopsies of 47 infertile men with nonobstructive azoospermia and co-cultured with a Sertoli cell monolayer. Age, infertility duration, medical/surgical history, testicular size, and testicular histologic findings were recorded. The patients were divided into 2 groups according to the growth/no growth of human SSC colonies in culture. As the main outcome measure, the number and diameter of germ cell-derived colonies were compared between 2 groups in days 8, 13, and 18 after cultivation with respect to the recorded parameters. RESULTS No difference was found between the 2 groups regarding the demographic/clinical parameters. Maturation arrest at the premeiotic spermatogonia stage was present in a considerably greater proportion in the group with growth of human SSC colonies compared with the group without growth of human SSC colonies (14 [45.1%] of 31 versus 3 [18.7%] of 16; P < .001) on days 8, 13, and 18 after culture. Maturation arrest at premeiotic SSCs was associated with a greater number and larger diameter of germ cell colonies compared with the maturation arrest at primary spermatocyte and secondary spermatocyte/spermatid stages (P < .001). CONCLUSION Infertile men with testicular histologic findings of maturation arrest at the premeiotic spermatogonia stage were seemingly the most appropriate candidates for testicular biopsy and in vitro propagation of human SSCs, regardless of their demographic/clinical characteristics.
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Affiliation(s)
- Mohammad Reza Nowroozi
- Department of Urology, Imam Khomeini General Hospital, Tehran University of Medical Sciences, Tehran, Iran
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Hyldig SMW, Ostrup O, Vejlsted M, Thomsen PD. Changes of DNA Methylation Level and Spatial Arrangement of Primordial Germ Cells in Embryonic Day 15 to Embryonic Day 28 Pig Embryos1. Biol Reprod 2011; 84:1087-93. [DOI: 10.1095/biolreprod.110.086082] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Abstract
The germ cell lineage is our lifelong reservoir of reproductive stem cells and our mechanism for transmitting genes to future generations. These highly specialised cells are specified early during development and then migrate to the embryonic gonads where sex differentiation occurs. Germ cell sex differentiation is directed by the somatic gonadal environment and is characterised by two distinct cell cycle states that are maintained until after birth. In the mouse, XY germ cells in a testis cease mitotic proliferation and enter G(1)/G(0) arrest from 12.5 dpc, while XX germ cells in an ovary enter prophase I of meiosis from 13.5 dpc. This chapter discusses the factors known to control proliferation and survival of germ cells during their journey of specification to sex differentiation during development.
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Affiliation(s)
- Cassy M Spiller
- Division of Molecular Genetics and Development, Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia
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8
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Bowles J, Koopman P. Sex determination in mammalian germ cells: extrinsic versus intrinsic factors. Reproduction 2010; 139:943-58. [DOI: 10.1530/rep-10-0075] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mammalian germ cells do not determine their sexual fate based on their XX or XY chromosomal constitution. Instead, sexual fate is dependent on the gonadal environment in which they develop. In a fetal testis, germ cells commit to the spermatogenic programme of development during fetal life, although they do not enter meiosis until puberty. In a fetal ovary, germ cells commit to oogenesis by entering prophase of meiosis I. Although it was believed previously that germ cells are pre-programmed to enter meiosis unless they are actively prevented from doing so, recent results indicate that meiosis is triggered by a signaling molecule, retinoic acid (RA). Meiosis is avoided in the fetal testis because a male-specifically expressed enzyme actively degrades RA during the critical time period. Additional extrinsic factors are likely to influence sexual fate of the germ cells, and in particular, we postulate that an additional male-specific fate-determining factor or factors is involved. The full complement of intrinsic factors that underlie the competence of gonadal germ cells to respond to RA and other extrinsic factors is yet to be defined.
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Jørgensen A, Nielsen JE, Morthorst JE, Bjerregaard P, Leffers H. Laser capture microdissection of gonads from juvenile zebrafish. Reprod Biol Endocrinol 2009; 7:97. [PMID: 19747405 PMCID: PMC2755477 DOI: 10.1186/1477-7827-7-97] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Accepted: 09/14/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Investigating gonadal gene expression is important in attempting to elucidate the molecular mechanism of sex determination and differentiation in the model species zebrafish. However, the small size of juvenile zebrafish and correspondingly their gonads complicates this type of investigation. Furthermore, the lack of a genetic sex marker in juvenile zebrafish prevents pooling gonads from several individuals. The aim of this study was to establish a method to isolate the gonads from individual juvenile zebrafish allowing future investigations of gonadal gene expression during sex determination and differentiation. METHODS The laser capture microdissection technique enables isolation of specific cells and tissues and thereby removes the noise of gene expression from other cells or tissues in the gene expression profile. A protocol developed for laser microdissection of human gonocytes was adjusted and optimised to isolate juvenile zebrafish gonads. RESULTS The juvenile zebrafish gonad is not morphologically distinguishable when using dehydrated cryosections on membrane slides and a specific staining method is necessary to identify the gonads. The protocol setup in this study allows staining, identification, isolation and subsequent RNA purification and amplification of gonads from individual juvenile zebrafish thereby enabling gonadal gene expression profiling. CONCLUSION The study presents a protocol for isolation of individual juvenile zebrafish gonads, which will enable future investigations of gonadal gene expression during the critical period of sex differentiation. Furthermore, the presented staining method is applicable to other species as it is directed towards alkaline phosphatase that is expressed in gonocytes and embryonic stem cells, which is conserved among vertebrate species.
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Affiliation(s)
- Anne Jørgensen
- Department of Science, Systems and Models, Roskilde University, Universitetsvej 1, DK-4000 Roskilde, Denmark
- Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - John E Nielsen
- University Department of Growth and Reproduction, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen ∅, Denmark
| | - Jane E Morthorst
- Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Poul Bjerregaard
- Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Henrik Leffers
- University Department of Growth and Reproduction, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen ∅, Denmark
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Eguizabal C, Shovlin TC, Durcova-Hills G, Surani A, McLaren A. Generation of primordial germ cells from pluripotent stem cells. Differentiation 2009; 78:116-23. [PMID: 19683852 DOI: 10.1016/j.diff.2009.07.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 07/05/2009] [Accepted: 07/06/2009] [Indexed: 01/21/2023]
Abstract
Embryonic stem (ES) cells, derived from pre-implantation embryo, embryonic germ (EG) cells, derived from embryonic precursors of gametes, primordial germ cells (PGCs), can differentiate into any cell type in the body. Moreover, ES cells have the capacity to differentiate into PGCs in vitro. In the present study we have shown the differentiation capacity of six EG cell lines to form PGCs in vitro, in comparison to ES cells. Cell lines were differentiated via embryoid body (EB) formation using the co-expression of mouse vasa homolog (Mvh) and Oct-4 to identify newly formed PGCs in vitro. We found an increase of PGC numbers in almost all analysed cell lines in 5-day-old EBs, thus suggesting that EG and ES cells have similar efficiency to generate PGCs. The addition of retinoic acid confirmed that the cultures had attained a PGC-like identity and continued to proliferate. Furthermore we have shown that the expression pattern of Prmt5 and H3K27me3 in newly formed PGCs is similar to that observed in embryonic day E11.5 PGCs in vivo. By co-culturing EBs with Chinese hamster ovary (CHO) cells some of the PGCs entered into meiosis, as judged by Scp3 expression. The derivation of germ cells from pluripotent stem cells in vitro could provide an invaluable model system to study both the genetic and epigenetic programming of germ cell development in vivo.
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Affiliation(s)
- Cristina Eguizabal
- Wellcome Trust/Cancer Research UK Gurdon Institute, Henry Wellcome Building of Cancer and Developmental Biology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK.
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Efficiency of adult mouse spermatogonial stem cell colony formation under several culture conditions. In Vitro Cell Dev Biol Anim 2009; 45:281-9. [DOI: 10.1007/s11626-008-9169-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2008] [Accepted: 12/16/2008] [Indexed: 01/15/2023]
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Maatouk DM, Kellam LD, Mann MRW, Lei H, Li E, Bartolomei MS, Resnick JL. DNA methylation is a primary mechanism for silencing postmigratory primordial germ cell genes in both germ cell and somatic cell lineages. Development 2006; 133:3411-8. [PMID: 16887828 DOI: 10.1242/dev.02500] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
DNA methylation is necessary for the silencing of endogenous retrotransposons and the maintenance of monoallelic gene expression at imprinted loci and on the X chromosome. Dynamic changes in DNA methylation occur during the initial stages of primordial germ cell development; however, all consequences of this epigenetic reprogramming are not understood. DNA demethylation in postmigratory primordial germ cells coincides with erasure of genomic imprints and reactivation of the inactive X chromosome, as well as ongoing germ cell differentiation events. To investigate a possible role for DNA methylation changes in germ cell differentiation, we have studied several marker genes that initiate expression at this time. Here, we show that the postmigratory germ cell-specific genes Mvh, Dazl and Scp3 are demethylated in germ cells, but not in somatic cells. Premature loss of genomic methylation in Dnmt1 mutant embryos leads to early expression of these genes as well as GCNA1, a widely used germ cell marker. In addition, GCNA1 is ectopically expressed by somatic cells in Dnmt1 mutants. These results provide in vivo evidence that postmigratory germ cell-specific genes are silenced by DNA methylation in both premigratory germ cells and somatic cells. This is the first example of ectopic gene activation in Dnmt1 mutant mice and suggests that dynamic changes in DNA methylation regulate tissue-specific gene expression of a set of primordial germ cell-specific genes.
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Affiliation(s)
- Danielle M Maatouk
- Department of Molecular Genetics and Microbiology, PO Box 100266, University of Florida, Gainesville, FL 32610-0266, USA
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Abstract
Stem-cell nomenclature is in a muddle! So-called stem cells may be self-renewing or emergent, oligopotent (uni- and multipotent) or pluri- and totipotent, cells with perpetual embryonic features or cells that have changed irreversibly. Ambiguity probably seeped into stem cells from common usage, flukes in biology's history beginning with Weismann's divide between germ and soma and Haeckel's biogenic law and ending with contemporary issues over the therapeutic efficacy of adult versus embryonic cells. Confusion centers on tissue dynamics, whether stem cells are properly members of emerging or steady-state populations. Clarity might yet be achieved by codifying differences between cells in emergent populations, including embryonic stem and embryonic germ (ES and EG) cells in tissue culture as opposed to self-renewing (SR) cells in steady-state populations.
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Affiliation(s)
- Stanley Shostak
- Department of Biological Sciences, University of Pittsburgh, PA 15260, USA
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Anjamrooz SH, Movahedin M, Tiraihi T, Mowla SJ. In vitro effects of epidermal growth factor, follicle stimulating hormone and testosterone on mouse spermatogonial cell colony formation. Reprod Fertil Dev 2006; 18:709-20. [PMID: 16930518 DOI: 10.1071/rd05126] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Accepted: 04/09/2006] [Indexed: 01/15/2023] Open
Abstract
The complex process of spermatogenesis is regulated by various factors. In the present study, the in vitro effects of epidermal growth factor (EGF), follicle stimulating hormone (FSH) and testosterone on spermatogonial cell colony formation were investigated, and the best colonising factor was chosen for treating cells before transplantation. Sertoli and spermatogonial cells were isolated from neonatal mouse testes. The identity of the cells was confirmed through analysis of morphology, alkaline phosphatase activity, immunoreactivity and transplantation. Co-cultured Sertoli and spermatogonial cells were treated with EGF, FSH and testosterone before colony assay. Results indicated that EGF is the best factor for in vitro colonisation of spermatogonial cells, but transplantation of the EGF-treated group did not show any significant change compared with the control groups. In conclusion, EGF increased in vitro colonisation of spermatogonial cells, but, as a result of differential effects, did not influence transplantation efficiency.
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Affiliation(s)
- S Hadi Anjamrooz
- Department of Anatomical Sciences, School of Medical Sciences, Tarbiat Modarres University, Tehran, Iran
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Baleato RM, Aitken RJ, Roman SD. Vitamin A regulation of BMP4 expression in the male germ line. Dev Biol 2005; 286:78-90. [PMID: 16120438 DOI: 10.1016/j.ydbio.2005.07.009] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2005] [Revised: 06/23/2005] [Accepted: 07/07/2005] [Indexed: 11/26/2022]
Abstract
The molecular mechanisms leading to male infertility in vitamin A deficient (VAD) rodents have never been fully elucidated. Here, we report an interaction between BMP4 and retinoid signaling pathways in germ cells that may help clarify the biochemical basis of VAD. Adult germ cells, in particular spermatogonia, expressed BMP4 at both the mRNA and protein levels. BMP4 expression was significantly up-regulated in the testes of VAD mice and was down-regulated in freshly isolated germ cells and VAD testes by retinol, but not retinoic acid. The retinoid-responsive gene, RARbeta, was not induced in germ cells following retinoid treatment. Examination of BMP4 promoter usage in spermatogonia and the VAD testis revealed that germ cells utilize the recently characterized BMP4 intron 2 promoter, in addition to the classical 1A and 1B promoters. The observed decrease in BMP4 in response to retinol was mediated by the 1A and intron 2 promoters of the BMP4 gene. Our results reflect a direct requirement for retinoids by germ cells for the resumption of spermatogenesis in VAD animals via mechanisms that involve the suppression of BMP4 expression.
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Affiliation(s)
- Rosa M Baleato
- Reproductive Science Group, School of Environmental and Life Sciences, University of Newcastle, NSW 2308, Australia
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Ishii M, Kanai Y, Kanai-Azuma M, Tajima Y, Wei TT, Kidokoro T, Sanai Y, Kurohmaru M, Hayashi Y. Adhesion activity of fetal gonadal cells to EGF and discoidin domains of milk fat globule-EGF factor 8 (MFG-E8), a secreted integrin-binding protein which is transiently expressed in mouse early gonadogenesis. ACTA ACUST UNITED AC 2005; 209:485-94. [PMID: 15891907 DOI: 10.1007/s00429-005-0463-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2005] [Indexed: 11/29/2022]
Abstract
MFG-E8, a secreted integrin-binding protein, consists of two EGF domains containing a RGD motif and two discoidin domains. In mouse embryogenesis, MFG-E8 is highly expressed in gonadal stromal cells near mesonephros at 11.5-12.5 dpc, but its function in gonadogenesis has not been characterized. To clarify a possible role of MFG-E8 in developing gonads, we analyzed the adhesion activity of 10.5-15.5 dpc gonadal cells to recombinant proteins of EGF or discoidin domains of MFG-E8. In EGF-coated wells, the gonadal cells at 11.5-12.5 dpc revealed a significantly higher adhesion activity as compared to those at 10.5 and 15.5 dpc, while discoidin domains showed a constant number of the adhered cells throughout these stages. To identify the adhesive cells of 11.5-dpc gonads, immunohistochemistry with anti-SF1/Ad4Bp antibody (a specific marker for supporting, steroidogenic, and coelomic epithelial cells) and staining for alkaline phosphatase (a germ cell marker) were carried out. As a result, EGF domains, as well as discoidin domains, were capable of binding to all three groups of SF1/Ad4Bp-positive and negative somatic cells, and germ cells of 11.5-dpc gonads. These findings therefore suggest that MFG-E8 mediates the cell-to-cell interaction among several somatic cell types and germ cells in mouse early gonadogenesis.
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Affiliation(s)
- Maki Ishii
- Department of Veterinary Anatomy, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
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Durcova-Hills G, Burgoyne P, McLaren A. Analysis of sex differences in EGC imprinting. Dev Biol 2004; 268:105-10. [PMID: 15031108 DOI: 10.1016/j.ydbio.2003.12.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2003] [Revised: 12/03/2003] [Accepted: 12/09/2003] [Indexed: 10/26/2022]
Abstract
Sex-specific differences are apparent in the methylation patterns of H19 and Igf2 imprinted genes in embryonic germ cells (EGCs) derived from 11.5 or 12.5 days post coitum (dpc) primordial germ cells (PGCs). Here we studied whether these differences are associated either with the sex chromosome constitution of the EGCs or with the sex of the genital ridge (testis versus ovary) from which the PGCs were isolated. For this purpose we derived pluripotent EGC lines from sex-reversed embryos, either XY embryos deleted for Sry (XY(Tdym1)) or XX embryos carrying an Sry transgene. Southern blotting of the EGC DNA was used to analyze the differentially methylated regions of Igf2 and H19. The analysis revealed that both genes were more methylated in EGCs with an XY sex chromosome constitution than in those with an XX sex chromosome constitution, irrespective of the phenotypic sex of the genital ridge from which the EGCs had been derived. We conclude that the sex-specific methylation is intrinsic and cell-autonomous, and is not due to any influence of the genital ridge somatic cells upon the PGCs.
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Affiliation(s)
- Gabriela Durcova-Hills
- The Wellcome Trust/Cancer Research UK Gurdon Institute of Cancer and Developmental Biology, Cambridge CB2 1QR, UK
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19
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Affiliation(s)
- Anne McLaren
- The Wellcome Trust/Cancer Research UK Institute of Cancer and Developmental Biology, Tennis Court Road, Cambridge CB2 1QR, UK.
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Maatouk DM, Resnick JL. Continuing primordial germ cell differentiation in the mouse embryo is a cell-intrinsic program sensitive to DNA methylation. Dev Biol 2003; 258:201-8. [PMID: 12781693 DOI: 10.1016/s0012-1606(03)00110-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The initial cohort of mammalian gametes is established by the proliferation of primordial germ cells in the early embryo. Primordial germ cells first appear in extraembyronic tissues and subsequently migrate to the developing gonad. Soon after they arrive in the gonad, the germ cells cease dividing and undertake sexually dimorphic patterns of development. Male germ cells arrest mitotically, while female germ cells directly enter meiotic prophase I. These sex-specific differentiation events are imposed upon a group of sex-common differentiation events that are shared by XX and XY germ cells. We have studied the appearance of GCNA1, a postmigratory sex-common germ cell marker, in cultures of premigratory germ cells to investigate how this differentiation program is regulated. Cultures in which proliferation was either inhibited or stimulated displayed a similar extent of differentiation as controls, suggesting that some differentiation events are the result of a cell-intrinsic program and are independent of cell proliferation. We also found that GCNA1 expression was accelerated by agents which promote DNA demethylation or histone acetylation. These results suggest that genomic demethylation of proliferative phase primordial germ cells is a mechanism by which germ cell maturation is coordinated.
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Affiliation(s)
- Danielle M Maatouk
- Department of Molecular Genetics and Microbiology, University of Florida, P.O. Box 10266, Gainesville, FL 32610-0266, USA
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Pérez-Armendariz EM, Lamoyi E, Mason JI, Cisneros-Armas D, Luu-The V, Bravo Moreno JF. Developmental regulation of connexin 43 expression in fetal mouse testicular cells. THE ANATOMICAL RECORD 2001; 264:237-46. [PMID: 11596006 DOI: 10.1002/ar.1164] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Multiple connexins have been identified in testicular cells. Several lines of evidences indicate that, among them, connexin 43 (Cx43) may be unique for control of gonad development and spermatogenesis. To date, however, it is not known whether Cx43 is expressed in the fetal testis and what possible types of cellular interactions mediated by this connexin are critical to male fertility. In the present work, expression of Cx43 was investigated at various developmental ages in cryosections from mouse testis by using specific antibodies against Cx43. In serial or double-labeled sections, Cx43 localization was compared with immunocytochemical distribution of steroidogenic enzyme, 3beta-hydroxysteroid dehydrogenase (3betaHSD), Mullerian inhibitory hormone (MIH), and germinal nuclear cell antigen (GCNA1), which are specific markers, respectively, of interstitial Leydig, Sertoli, and germinal cells. Sections were analyzed by fluorescence microscopy. We found that Cx43 immunofluorescence (IF) was uniformly distributed in the undifferentiated gonad at 11.5 days post coitus (dpc) and in cells of the mesonephric tubules. In the undifferentiated gonad, Cx43 was localized between primordial germ cells and somatic cells. At 12.5 dpc, when the gonad has undergone sexual differentiation, in the interstitium Cx43 was localized in Leydig cells and in the seminiferous cord it was localized between adjacent Sertoli cells. In Leydig and Sertoli cells, Cx43 labeling increased at 14.5, 16.5, and 18.5 dpc. From day 12.5 up to 18.5 dpc, Cx43 was also localized in cell borders between germinal and Sertoli cells. In conclusion, this study demonstrates that from the earliest stages of gonadal development, Cx43 is expressed in the principal cell types that participate in the control of male fertility. It also shows that Cx43 expression in Leydig and Sertoli cells increase during fetal life. Finally, it provides evidence that, throughout embryonic life, Cx43 forms gap junctions between Sertoli and germinal cells.
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Affiliation(s)
- E M Pérez-Armendariz
- Departamento de Biología Celular, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, D. F., 04510.
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