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Kubiura-Ichimaru M, Penfold C, Kojima K, Dollet C, Yabukami H, Semi K, Takashima Y, Boroviak T, Kawaji H, Woltjen K, Minoda A, Sasaki E, Watanabe T. mRNA-based generation of marmoset PGCLCs capable of differentiation into gonocyte-like cells. Stem Cell Reports 2023; 18:1987-2002. [PMID: 37683645 PMCID: PMC10656353 DOI: 10.1016/j.stemcr.2023.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 09/10/2023] Open
Abstract
Primate germ cell development remains largely unexplored due to limitations in sample collection and the long duration of development. In mice, primordial germ cell-like cells (PGCLCs) derived from pluripotent stem cells (PSCs) can develop into functional gametes by in vitro culture or in vivo transplantation. Such PGCLC-mediated induction of mature gametes in primates is highly useful for understanding human germ cell development. Since marmosets generate functional sperm earlier than other species, recapitulating the whole male germ cell development process is technically more feasible. Here, we induced the differentiation of iPSCs into gonocyte-like cells via PGCLCs in marmosets. First, we developed an mRNA transfection-based method to efficiently generate PGCLCs. Subsequently, to promote PGCLC differentiation, xenoreconstituted testes (xrtestes) were generated in the mouse kidney capsule. PGCLCs show progressive DNA demethylation and stepwise expression of developmental marker genes. This study provides an efficient platform for the study of marmoset germ cell development.
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Affiliation(s)
- Musashi Kubiura-Ichimaru
- Central Institute for Experimental Animals, 3-25-12 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan; Division of Molecular Genetics & Epigenetics, Department of Biomolecular Science, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan
| | - Christopher Penfold
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, UK; Wellcome Trust-Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, UK; Centre for Trophoblast Research, University of Cambridge, Downing Site, Cambridge CB2 3EG, UK; Wellcome Trust - Medical Research Council Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Kazuaki Kojima
- Central Institute for Experimental Animals, 3-25-12 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan; National Center for Child Health and Development, Tokyo 157-8535, Japan
| | - Constance Dollet
- Central Institute for Experimental Animals, 3-25-12 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan; National Center for Child Health and Development, Tokyo 157-8535, Japan
| | - Haruka Yabukami
- Laboratory for Cellular Epigenomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa 230-0045, Japan
| | - Katsunori Semi
- Department of Life Science Frontiers, Center for iPS Research and Application (CiRA), Kyoto University, Kyoto 606-8507, Japan
| | - Yasuhiro Takashima
- Department of Life Science Frontiers, Center for iPS Research and Application (CiRA), Kyoto University, Kyoto 606-8507, Japan
| | - Thorsten Boroviak
- Wellcome Trust - Medical Research Council Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Hideya Kawaji
- Research Center for Genome & Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Preventive Medicine and Applied Genomics Unit, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa 230-0045, Japan
| | - Knut Woltjen
- Department of Life Science Frontiers, Center for iPS Research and Application (CiRA), Kyoto University, Kyoto 606-8507, Japan
| | - Aki Minoda
- Laboratory for Cellular Epigenomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Kanagawa 230-0045, Japan; Department of Cell Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Radboud University, Nijmegen, the Netherlands
| | - Erika Sasaki
- Central Institute for Experimental Animals, 3-25-12 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
| | - Toshiaki Watanabe
- Central Institute for Experimental Animals, 3-25-12 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan; National Center for Child Health and Development, Tokyo 157-8535, Japan.
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2
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Abstract
Male germ cells undergo a complex sequence of developmental events throughout fetal and postnatal life that culminate in the formation of haploid gametes: the spermatozoa. Errors in these processes result in infertility and congenital abnormalities in offspring. Male germ cell development starts when pluripotent cells undergo specification to sexually uncommitted primordial germ cells, which act as precursors of both oocytes and spermatozoa. Male-specific development subsequently occurs in the fetal testes, resulting in the formation of spermatogonial stem cells: the foundational stem cells responsible for lifelong generation of spermatozoa. Although deciphering such developmental processes is challenging in humans, recent studies using various models and single-cell sequencing approaches have shed new insight into human male germ cell development. Here, we provide an overview of cellular, signaling and epigenetic cascades of events accompanying male gametogenesis, highlighting conserved features and the differences between humans and other model organisms.
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Affiliation(s)
- John Hargy
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104, USA
| | - Kotaro Sasaki
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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3
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Greeson KW, Crow KMS, Edenfield RC, Easley CA. Inheritance of paternal lifestyles and exposures through sperm DNA methylation. Nat Rev Urol 2023:10.1038/s41585-022-00708-9. [PMID: 36653672 DOI: 10.1038/s41585-022-00708-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2022] [Indexed: 01/19/2023]
Abstract
Many different lifestyle factors and chemicals present in the environment are a threat to the reproductive tracts of humans. The potential for parental preconception exposure to alter gametes and for these alterations to be passed on to offspring and negatively affect embryo growth and development is of concern. The connection between maternal exposures and offspring health is a frequent focus in epidemiological studies, but paternal preconception exposures are much less frequently considered and are also very important determinants of offspring health. Several environmental and lifestyle factors in men have been found to alter sperm epigenetics, which can regulate gene expression during early embryonic development. Epigenetic information is thought to be a mechanism that evolved for organisms to pass on information about their lived experiences to offspring. DNA methylation is a well-studied epigenetic regulator that is sensitive to environmental exposures in somatic cells and sperm. The continuous production of sperm from spermatogonial stem cells throughout a man's adult life and the presence of spermatogonial stem cells outside of the blood-testis barrier makes them susceptible to environmental insults. Furthermore, altered sperm DNA methylation patterns can be maintained throughout development and ultimately result in impairments, which could predispose offspring to disease. Innovations in human stem cell-based spermatogenic models can be used to elucidate the paternal origins of health and disease.
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Affiliation(s)
- Katherine W Greeson
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, USA.,Regenerative Bioscience Center, University of Georgia, Athens, GA, USA
| | - Krista M S Crow
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, USA.,Regenerative Bioscience Center, University of Georgia, Athens, GA, USA
| | - R Clayton Edenfield
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, USA.,Regenerative Bioscience Center, University of Georgia, Athens, GA, USA
| | - Charles A Easley
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, USA. .,Regenerative Bioscience Center, University of Georgia, Athens, GA, USA.
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4
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Blaauwendraad SM, Jaddoe VW, Santos S, Kannan K, Dohle GR, Trasande L, Gaillard R. Associations of maternal urinary bisphenol and phthalate concentrations with offspring reproductive development. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 309:119745. [PMID: 35820574 DOI: 10.1016/j.envpol.2022.119745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 07/04/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
Fetal exposure to bisphenols and phthalates may influence development of the reproductive system. In a population-based, prospective cohort study of 1059 mother-child pairs, we examined the associations of maternal gestational urinary bisphenols and phthalates concentrations with offspring reproductive development from infancy until 13 years. We measured urinary bisphenol and phthalate concentrations in each trimester. We obtained information on cryptorchidism or hypospadias after birth from medical records. At 9.7 years, we measured testicular and ovarian volume by MRI. At 13.5 years, we measured child Tanner stages and menstruation through questionnaire. We performed linear or logistic regression models for boys and girls to assess the associations of maternal urinary average and trimester-specific bisphenols and phthalates with child reproductive outcomes. Next, to further explore potential synergistic or additive effects of exposures together, we performed mixed exposure models using a quantile g computation approach. Models were adjusted for maternal age, ethnicity, body-mass index, education, parity, energy intake, smoking and alcohol use, and child's gestational age at birth, birthweight and body-mass index. In boys, no associations of maternal gestational phthalate or bisphenol with offspring cryptorchidism and hypospadias were found. Higher maternal high-molecular-weight phthalate and total bisphenol, but not phthalic acid or low-molecular-weight phthalate, were associated with larger child testicular volume at 10 years. Higher maternal phthalic acid and total bisphenol were associated with earlier genital and pubic hair development at 13 years, respectively (p-values<0.05). In girls, we found no associations of maternal urinary bisphenol and phthalate with ovarian volume or menstrual age. Only higher maternal urinary high-molecular-weight phthalate was associated with earlier pubic hair development at 13 years (p-values <0.05). Higher mixture exposure was associated with earlier pubic hair development in both sexes. In conclusion, higher maternal gestational urinary bisphenol and phthalate concentrations were associated with alterations in offspring reproductive development, mainly in boys.
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Affiliation(s)
- Sophia M Blaauwendraad
- The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, the Netherlands; Department of Pediatrics, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Vincent Wv Jaddoe
- The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, the Netherlands; Department of Pediatrics, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Susana Santos
- The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, the Netherlands; Department of Pediatrics, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Kurunthachalam Kannan
- Department of Paediatrics, New York University School of Medicine, New York City, NY, 10016, USA; Department of Environmental Medicine, New York University School of Medicine, New York City, NY, 10016, USA
| | - Gert R Dohle
- Department of Urology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Leonardo Trasande
- Department of Paediatrics, New York University School of Medicine, New York City, NY, 10016, USA; Department of Environmental Medicine, New York University School of Medicine, New York City, NY, 10016, USA; Department of Population Health, New York University School of Medicine, New York City, NY, USA; New York University Wagner School of Public Service, New York City, NY, 10016, USA; New York University College of Global Public Health, New York City, NY, 10016, USA
| | - Romy Gaillard
- The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, the Netherlands; Department of Pediatrics, Erasmus MC, University Medical Center, Rotterdam, the Netherlands.
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Matilionyte G, Rimmer MP, Spears N, Anderson RA, Mitchell RT. Cisplatin Effects on the Human Fetal Testis - Establishing the Sensitive Period for (Pre)Spermatogonial Loss and Relevance for Fertility Preservation in Pre-Pubertal Boys. Front Endocrinol (Lausanne) 2022; 13:914443. [PMID: 35909565 PMCID: PMC9330899 DOI: 10.3389/fendo.2022.914443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/07/2022] [Indexed: 11/18/2022] Open
Abstract
Background Exposure to chemotherapy during childhood can impair future fertility. Studies using in vitro culture have shown exposure to platinum-based alkylating-like chemotherapy reduces the germ cell number in the human fetal testicular tissues. We aimed to determine whether effects of exposure to cisplatin on the germ cell sub-populations are dependent on the gestational age of the fetus and what impact this might have on the utility of using human fetal testis cultures to model chemotherapy exposure in childhood testis. Methods We utilised an in vitro culture system to culture pieces of human fetal testicular tissues (total n=23 fetuses) from three different gestational age groups (14-16 (early), 17-19 (mid) and 20-22 (late) gestational weeks; GW) of the second trimester. Tissues were exposed to cisplatin or vehicle control for 24 hours, analysing the tissues 72 and 240 hours post-exposure. Number of germ cells and their sub-populations, including gonocytes and (pre)spermatogonia, were quantified. Results Total germ cell number and number of both germ cell sub-populations were unchanged at 72 hours post-exposure to cisplatin in the testicular tissues from fetuses of the early (14-16 GW) and late (20-22 GW) second trimester. In the testicular tissues from fetuses of mid (17-19 GW) second trimester, total germ cell and gonocyte number were significantly reduced, whilst (pre)spermatogonial number was unchanged. At 240 hours post-exposure, the total number of germ cells and that of both sub-populations was significantly reduced in the testicular tissues from fetuses of mid- and late-second trimester, whilst germ cells in early-second trimester tissues were unchanged at this time-point. Conclusions In vitro culture of human fetal testicular tissues can be a useful model system to investigate the effects of chemotherapy-exposure on germ cell sub-populations during pre-puberty. Interpretation of the results of such studies in terms of relevance to later (infant and pre-pubertal) developmental stages should take into account the changes in germ cell composition and periods of germ cell sensitivity in the human fetal testis.
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Affiliation(s)
- Gabriele Matilionyte
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Michael P Rimmer
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Norah Spears
- Biomedical Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Richard A Anderson
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Rod T Mitchell
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
- Department of Paediatric Diabetes and Endocrinology, Royal Hospital for Children & Young People, Edinburgh, United Kingdom
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Sharma S, Klaverkamp RS, Wistuba J, Schlatt S. Limited spermatogenic differentiation of testicular tissue from prepubertal marmosets (Callithrix jacchus) in an in vitro organ culture system. Mol Cell Endocrinol 2022; 539:111488. [PMID: 34637880 DOI: 10.1016/j.mce.2021.111488] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 12/21/2022]
Abstract
PURPOSE of the research: To achieve male fertility preservation and restoration, experimental strategies for in vitro germ cell differentiation are required. The effects of two different culture conditions on in vitro maintenance and differentiation of non-human primate germ cells was studied. Three testes from three 6-month-old marmosets were cultured using a gas-liquid interphase system for 12 days. Testicular maturation in pre-culture control and samples cultured in gonadotropin and serum supplemented and non-supplemented culture samples was evaluated using Periodic Acid-Schiff (PAS) and immunohistochemical stainings. PRINCIPLE RESULTS Gonadotropins and serum-supplemented tissues demonstrate up to meiotic differentiation (BOULE + Pachytene spermatocyte) and advanced localization of germ cells (MAGEA4+). Moreover, complex (with gonadotropin and marmoset monkey serum) conditions induced progression in somatic cell maturation with advanced seminiferous epithelial organization, maintenance of encapsulation of cultured fragments with peritubular-myoid cells, preservation of tubular structural integrity and architecture. MAJOR CONCLUSIONS We report stimulation-dependent in vitro meiotic transition in non-human primate testes. This model represents a novel ex vivo approach to obtain crucial developmental progression.
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Affiliation(s)
- Swati Sharma
- Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer Campus 1, Building D11, 48149, Münster, Germany
| | - Reinhild-Sandhowe Klaverkamp
- Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer Campus 1, Building D11, 48149, Münster, Germany
| | - Joachim Wistuba
- Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer Campus 1, Building D11, 48149, Münster, Germany
| | - Stefan Schlatt
- Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer Campus 1, Building D11, 48149, Münster, Germany.
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7
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Heckmann L, Langenstroth-Röwer D, Wistuba J, Portela JMD, van Pelt AMM, Redmann K, Stukenborg JB, Schlatt S, Neuhaus N. The initial maturation status of marmoset testicular tissues has an impact on germ cell maintenance and somatic cell response in tissue fragment culture. Mol Hum Reprod 2021; 26:374-388. [PMID: 32236422 DOI: 10.1093/molehr/gaaa024] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 03/13/2020] [Indexed: 11/13/2022] Open
Abstract
Successful in vitro spermatogenesis was reported using immature mouse testicular tissues in a fragment culture approach, raising hopes that this method could also be applied for fertility preservation in humans. Although maintaining immature human testicular tissue fragments in culture is feasible for an extended period, it remains unknown whether germ cell survival and the somatic cell response depend on the differentiation status of tissue. Employing the marmoset monkey (Callithrix jacchus), we aimed to assess whether the maturation status of prepubertal and peri-/pubertal testicular tissues influence the outcome of testis fragment culture. Testicular tissue fragments from 4- and 8-month-old (n = 3, each) marmosets were cultured and evaluated after 0, 7, 14, 28 and 42 days. Immunohistochemistry was performed for identification and quantification of germ cells (melanoma-associated antigen 4) and Sertoli cell maturation status (anti-Müllerian hormone: AMH). During testis fragment culture, spermatogonial numbers were significantly reduced (P < 0.05) in the 4- but not 8-month-old monkeys, at Day 0 versus Day 42 of culture. Moreover, while Sertoli cells from 4-month-old monkeys maintained an immature phenotype (i.e. AMH expression) during culture, AMH expression was regained in two of the 8-month-old monkeys. Interestingly, progression of differentiation to later meiotic stage was solely observed in one 8-month-old marmoset, which was at an intermediate state regarding germ cell content, with gonocytes as well as spermatocytes present, as well as Sertoli cell maturation status. Although species-specific differences might influence the outcome of testis fragment experiments in vitro, our study demonstrated that the developmental status of the testicular tissues needs to be considered as it seems to be decisive for germ cell maintenance, somatic cell response and possibly the differentiation potential.
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Affiliation(s)
- L Heckmann
- Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
| | - D Langenstroth-Röwer
- Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
| | - J Wistuba
- Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
| | - J M D Portela
- Center for Reproductive Medicine, Research Institute Reproduction and Development, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - A M M van Pelt
- Center for Reproductive Medicine, Research Institute Reproduction and Development, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - K Redmann
- Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
| | - J B Stukenborg
- NORDFERTIL Research Lab Stockholm, Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet and Karolinska University Hospital, 17164 Solna, Sweden
| | - S Schlatt
- Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
| | - N Neuhaus
- Centre of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Biology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
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Kilcoyne KR, Mitchell RT. Effect of environmental and pharmaceutical exposures on fetal testis development and function: a systematic review of human experimental data. Hum Reprod Update 2020; 25:397-421. [PMID: 30869130 PMCID: PMC6601394 DOI: 10.1093/humupd/dmz004] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 12/06/2018] [Accepted: 01/23/2019] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Overall, the incidence of male reproductive disorders has increased in recent decades. Testicular development during fetal life is crucial for subsequent male reproductive function. Non-genomic factors such as environmental chemicals, pharmaceuticals and lifestyle have been proposed to impact on human fetal testicular development resulting in subsequent effects on male reproductive health. Whilst experimental studies using animal models have provided support for this hypothesis, more recently a number of experimental studies using human tissues and cells have begun to translate these findings to determine direct human relevance. OBJECTIVE AND RATIONALE The objective of this systematic review was to provide a comprehensive description of the evidence for effects of prenatal exposure(s) on human fetal testis development and function. We present the effects of environmental, pharmaceutical and lifestyle factors in experimental systems involving exposure of human fetal testis tissues and cells. Comparison is made with existing epidemiological data primarily derived from a recent meta-analysis. SEARCH METHODS For identification of experimental studies, PubMed and EMBASE were searched for articles published in English between 01/01/1966 and 13/07/2018 using search terms including ‘endocrine disruptor’, ‘human’, ‘fetal’, ‘testis’, ‘germ cells’, ‘testosterone’ and related search terms. Abstracts were screened for selection of full-text articles for further interrogation. Epidemiological studies involving exposure to the same agents were extracted from a recent systematic review and meta-analysis. Additional studies were identified through screening of bibliographies of full-texts of articles identified through the initial searches. OUTCOMES A total of 25 experimental studies and 44 epidemiological studies were included. Consistent effects of analgesic and phthalate exposure on human fetal germ cell development are demonstrated in experimental models, correlating with evidence from epidemiological studies and animal models. Furthermore, analgesic-induced reduction in fetal testosterone production, which predisposes to the development of male reproductive disorders, has been reported in studies involving human tissues, which also supports data from animal and epidemiological studies. However, whilst reduced testosterone production has been demonstrated in animal studies following exposure(s) to a variety of environmental chemicals including phthalates and bisphenol A, these effects are not reproduced in experimental approaches using human fetal testis tissues. WIDER IMPLICATIONS Direct experimental evidence for effects of prenatal exposure(s) on human fetal testis development and function exists. However, for many exposures the data is limited. The increasing use of human-relevant models systems in which to determine the effects of environmental exposure(s) (including mixed exposures) on development and function of human tissues should form an important part of the process for assessment of such exposures by regulatory bodies to take account of animal–human differences in susceptibility.
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Affiliation(s)
- Karen R Kilcoyne
- MRC Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, UK
| | - Rod T Mitchell
- MRC Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, UK.,Royal Hospital for Sick Children, Edinburgh, UK
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Kurek M, Albalushi H, Hovatta O, Stukenborg JB. Human Pluripotent Stem Cells in Reproductive Science-a Comparison of Protocols Used to Generate and Define Male Germ Cells from Pluripotent Stem Cells. Int J Mol Sci 2020; 21:ijms21031028. [PMID: 32033159 PMCID: PMC7038013 DOI: 10.3390/ijms21031028] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 01/30/2020] [Accepted: 02/01/2020] [Indexed: 12/17/2022] Open
Abstract
Globally, fertility-related issues affect around 15% of couples. In 20%–30% of cases men are solely responsible, and they contribute in around 50% of all cases. Hence, understanding of in vivo germ-cell specification and exploring different angles of fertility preservation and infertility intervention are considered hot topics nowadays, with special focus on the use of human pluripotent stem cells (hPSCs) as a source of in vitro germ-cell generation. However, the generation of male germ cells from hPSCs can currently be considered challenging, making a judgment on the real perspective of these innovative approaches difficult. Ever since the first spontaneous germ-cell differentiation studies, using human embryonic stem cells, various strategies, including specific co-cultures, gene over-expression, and addition of growth factors, have been applied for human germ-cell derivation. In line with the variety of differentiation methods, the outcomes have ranged from early and migratory primordial germ cells up to post-meiotic spermatids. This variety of culture approaches and cell lines makes comparisons between protocols difficult. Considering the diverse strategies and outcomes, we aim in this mini-review to summarize the literature regarding in vitro derivation of human male germ cells from hPSCs, while keeping a particular focus on the culture methods, growth factors, and cell lines used.
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Affiliation(s)
- Magdalena Kurek
- NORDFERTIL Research Lab Stockholm, Childhood Cancer Research Unit, Department of Women’s and Children’s Health, Karolinska Institutet, and Karolinska University Hospital, 17164 Solna, Sweden; (M.K.); (H.A.)
| | - Halima Albalushi
- NORDFERTIL Research Lab Stockholm, Childhood Cancer Research Unit, Department of Women’s and Children’s Health, Karolinska Institutet, and Karolinska University Hospital, 17164 Solna, Sweden; (M.K.); (H.A.)
- College of Medicine and Health Sciences, Sultan Qaboos University, 123 Muscat, Oman
| | - Outi Hovatta
- Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet and University Hospital Karolinska Institutet, 141 52 Huddinge, Sweden;
| | - Jan-Bernd Stukenborg
- NORDFERTIL Research Lab Stockholm, Childhood Cancer Research Unit, Department of Women’s and Children’s Health, Karolinska Institutet, and Karolinska University Hospital, 17164 Solna, Sweden; (M.K.); (H.A.)
- Correspondence: ; Tel.: +46-8524-82788
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10
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Manku G, Papadopoulos P, Boisvert A, Culty M. Cyclooxygenase 2 (COX2) expression and prostaglandin synthesis in neonatal rat testicular germ cells: Effects of acetaminophen and ibuprofen. Andrology 2019; 8:691-705. [DOI: 10.1111/andr.12727] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 11/04/2019] [Accepted: 11/04/2019] [Indexed: 12/01/2022]
Affiliation(s)
- Gurpreet Manku
- The Research Institute of the McGill University Health Centre Montreal QC Canada
- Department of Medicine McGill University Montreal QC Canada
| | - Philippos Papadopoulos
- The Research Institute of the McGill University Health Centre Montreal QC Canada
- Department of Regulatory and Quality Sciences School of Pharmacy University of Southern California Los Angeles CA USA
| | - Annie Boisvert
- The Research Institute of the McGill University Health Centre Montreal QC Canada
- Department of Medicine McGill University Montreal QC Canada
| | - Martine Culty
- The Research Institute of the McGill University Health Centre Montreal QC Canada
- Department of Medicine McGill University Montreal QC Canada
- Department of Pharmacology and Pharmaceutical Sciences School of Pharmacy University of Southern California Los Angeles CA USA
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11
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Mäkelä JA, Koskenniemi JJ, Virtanen HE, Toppari J. Testis Development. Endocr Rev 2019; 40:857-905. [PMID: 30590466 DOI: 10.1210/er.2018-00140] [Citation(s) in RCA: 148] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/17/2018] [Indexed: 12/28/2022]
Abstract
Production of sperm and androgens is the main function of the testis. This depends on normal development of both testicular somatic cells and germ cells. A genetic program initiated from the Y chromosome gene sex-determining region Y (SRY) directs somatic cell specification to Sertoli cells that orchestrate further development. They first guide fetal germ cell differentiation toward spermatogenic destiny and then take care of the full service to spermatogenic cells during spermatogenesis. The number of Sertoli cells sets the limits of sperm production. Leydig cells secrete androgens that determine masculine development. Testis development does not depend on germ cells; that is, testicular somatic cells also develop in the absence of germ cells, and the testis can produce testosterone normally to induce full masculinization in these men. In contrast, spermatogenic cell development is totally dependent on somatic cells. We herein review germ cell differentiation from primordial germ cells to spermatogonia and development of the supporting somatic cells. Testicular descent to scrota is necessary for normal spermatogenesis, and cryptorchidism is the most common male birth defect. This is a mild form of a disorder of sex differentiation. Multiple genetic reasons for more severe forms of disorders of sex differentiation have been revealed during the last decades, and these are described along with the description of molecular regulation of testis development.
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Affiliation(s)
- Juho-Antti Mäkelä
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Jaakko J Koskenniemi
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland.,Department of Pediatrics, Turku University Hospital, Turku, Finland
| | - Helena E Virtanen
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Jorma Toppari
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland.,Department of Pediatrics, Turku University Hospital, Turku, Finland
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12
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Fetal life shapes adult male reproductive function. THE LANCET CHILD & ADOLESCENT HEALTH 2018; 2:695-696. [PMID: 30236372 DOI: 10.1016/s2352-4642(18)30276-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 08/13/2018] [Indexed: 11/22/2022]
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13
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Tharmalingam MD, Jorgensen A, Mitchell RT. Experimental models of testicular development and function using human tissue and cells. Mol Cell Endocrinol 2018; 468:95-110. [PMID: 29309804 DOI: 10.1016/j.mce.2017.12.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 12/21/2017] [Accepted: 12/21/2017] [Indexed: 12/17/2022]
Abstract
The mammalian testis has two main roles, production of gametes for reproduction and synthesis of steroid- and peptide hormones for masculinization. These processes are tightly regulated and involve complex interactions between a number of germ and somatic cell-types that comprise a unique microenvironment known as the germ stem cell niche. In humans, failure of normal testicular development or function is associated with susceptibility to a variety of male reproductive disorders including disorders of sex development, infertility and testicular cancer. Whilst studies in rodent models have provided detailed insight into the signaling pathways and molecular mechanisms that regulate the testis, there are important species differences in testicular development, function and reproductive disorders that highlight the need for suitable experimental models utilising human testicular tissues or cells. In this review, we outline experimental approaches used to sustain cells and tissue from human testis at different developmental time-points and discuss relevant end-points. These include survival, proliferation and differentiation of cell lineages within the testis as well as autocrine, paracrine and endocrine function. We also highlight the utility of these experimental approaches for modelling the effects of environmental exposures on testicular development and function.
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Affiliation(s)
- Melissa D Tharmalingam
- MRC Centre for Reproductive Health, The University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK
| | - Anne Jorgensen
- Department of Growth and Reproduction, University Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Rod T Mitchell
- MRC Centre for Reproductive Health, The University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK; Department of Endocrinology and Diabetes, Edinburgh Royal Hospital for Sick Children, 9 Sciennes Road, Edinburgh, EH9 1LF, Scotland, UK.
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14
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Rehman S, Usman Z, Rehman S, AlDraihem M, Rehman N, Rehman I, Ahmad G. Endocrine disrupting chemicals and impact on male reproductive health. Transl Androl Urol 2018; 7:490-503. [PMID: 30050807 PMCID: PMC6043754 DOI: 10.21037/tau.2018.05.17] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Endocrine disrupting chemicals (EDCs) have been known to adversely affect the endocrine system leading to compromised functions of hormones. The presence of these compounds in everyday products such as canned food, water bottles, plastics, cosmetics, fertilizers, kid’s toys and many others goods is a greater concern for general population. The persistent and long-term use of EDCs has deleterious effects on human reproductive health by interfering with the synthesis and mechanism of action of sex hormones. Any change during the synthesis or action of the sex hormones may result in abnormal reproductive functions which includes developmental anomalies in the reproductive tract and decline in semen quality. The present paper provides an overview of the EDCs and their possible impact on male reproductive health with major focus on semen quality which leads to male infertility.
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Affiliation(s)
- Saba Rehman
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Zeenat Usman
- Department of Physiology, University of Health Sciences, Lahore, Pakistan
| | - Sabeen Rehman
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | | | - Noor Rehman
- Department of Biological Sciences, Binghamton University, NY, USA
| | - Ibraheem Rehman
- Department of Biological Sciences, Cornell University, Ithaca, NY, USA
| | - Gulfam Ahmad
- Department of Physiology, University of Health Sciences, Lahore, Pakistan.,Human Reproduction Unit, Kolling Institute, Sydney Medical School, Sydney University, Sydney, Australia
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15
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Smart E, Lopes F, Rice S, Nagy B, Anderson RA, Mitchell RT, Spears N. Chemotherapy drugs cyclophosphamide, cisplatin and doxorubicin induce germ cell loss in an in vitro model of the prepubertal testis. Sci Rep 2018; 8:1773. [PMID: 29379115 PMCID: PMC5788858 DOI: 10.1038/s41598-018-19761-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 12/22/2017] [Indexed: 11/09/2022] Open
Abstract
Long term survival rates for childhood cancers is steadily increasing, however cancer survivors can experience fertility problems as a consequence of chemotherapy treatment. This is particularly problematic for young boys, for whom no fertility preservation treatment is yet established. Here, we have determined the effects on prepubertal mouse testis of three commonly used chemotherapy drugs; cyclophosphamide (using its active metabolite phosphoramide mustard), cisplatin and doxorubicin, exposing testicular fragments to a clinically relevant range of concentrations in vitro. All three drugs induced a specific and highly significant loss of germ cells, including spermatogonial stem cells. In contrast, there was no significant effect on somatic cells, for either Sertoli or interstitial cells. Time course analysis of cleaved Caspase-3 expression showed a significant increase in apoptosis eight hours prior to a detectable decrease in germ cell numbers following exposure to phosphoramide mustard or cisplatin, although this pattern was not seen following doxorubicin-exposure. Moreover, analysis of DNA damage at 16 h showed increased γH2AX expression in response to all three drugs. Overall, results show that cisplatin, doxorubicin and cyclophosphamide all specifically induce loss of germ cells, including of spermatogonial stem cells, in the prepubertal mouse testis at concentrations relevant to human therapeutic exposures.
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Affiliation(s)
- Ellie Smart
- Biomedical Sciences, University of Edinburgh, Edinburgh, EH8 9XD, United Kingdom.,Center for Dermatology Research, University of Manchester, Manchester, United Kingdom
| | - Federica Lopes
- Biomedical Sciences, University of Edinburgh, Edinburgh, EH8 9XD, United Kingdom
| | - Siobhan Rice
- Biomedical Sciences, University of Edinburgh, Edinburgh, EH8 9XD, United Kingdom.,Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Oxford, OX3 9DS,, United Kingdom
| | - Boglarka Nagy
- Biomedical Sciences, University of Edinburgh, Edinburgh, EH8 9XD, United Kingdom
| | - Richard A Anderson
- MRC Centre for Reproductive Health, University of Edinburgh, Edinburgh, EH16 4TJ, United Kingdom
| | - Rod T Mitchell
- MRC Centre for Reproductive Health, University of Edinburgh, Edinburgh, EH16 4TJ, United Kingdom
| | - Norah Spears
- Biomedical Sciences, University of Edinburgh, Edinburgh, EH8 9XD, United Kingdom.
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16
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Sharma S, Sandhowe-Klaverkamp R, Schlatt S. Differentiation of Testis Xenografts in the Prepubertal Marmoset Depends on the Sex and Status of the Mouse Host. Front Endocrinol (Lausanne) 2018; 9:467. [PMID: 30210448 PMCID: PMC6123353 DOI: 10.3389/fendo.2018.00467] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/30/2018] [Indexed: 12/31/2022] Open
Abstract
This study investigates the effects of the endocrine milieu of immunodeficient mouse host (intact vs. castrated male, intact male vs. intact female) on prepubertal marmoset (Callithrix jacchus) testicular xenografts. Previous marmoset xenografting studies used castrated nude mouse hosts which did not support efficient graft survival and maturation. Due to the distinct endocrine milieu in marmosets with a deletion of exon 10 in the LH receptor, we wanted to explore whether the most efficient xenograft development occurs in intact male mouse hosts compared to intact females or castrated males. We xenografted freshly isolated tissue from prepubertal marmosets (age range 4-6 months) into the back skin of three groups of nude mice (intact male, castrated male, and intact female). We collected serum for endocrine determinations and grafts after 20 weeks and determined hormonal/reproductive status, graft survival, somatic cell development and initiation of germ cell differentiation. Graft development, tubular integrity, and germ cell differentiation status in the grafts retrieved from different hosts was scored by morphometric analysis. The influence of the different endocrine status was compared between groups of hosts. Endocrine readouts and histological endpoints in xenografts substantiate that grafts were exposed to different microenvironments and responded with host specific developmental patterns. The intact male hosts supported the most significant progression of germ cell development. Our data provide evidence for the important role of the host milieu on survival and differentiation of marmoset xenografts. The xenografting model offers innovative avenues to exploit development and endocrine effects in the primate marmoset testis using limited numbers of non-human primates for the experimental settings.
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17
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Picut CA, Ziejewski MK, Stanislaus D. Comparative Aspects of Pre- and Postnatal Development of the Male Reproductive System. Birth Defects Res 2017; 110:190-227. [PMID: 29063715 DOI: 10.1002/bdr2.1133] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 08/29/2017] [Accepted: 08/30/2017] [Indexed: 01/01/2023]
Abstract
This review describes pre- and postnatal development of the male reproductive system in humans and laboratory animals, and highlights species differences in the timing and control of hormonal and morphologic events. Major differences are that the fetal testis is dependent on gonadotropins in humans, but is independent of such in rats; humans have an extended postnatal quiescent period, whereas rats exhibit no quiescence; and events such as secretion by the prostate and seminal vesicles, testicular descent, and the appearance of spermatogonia are all prenatal events in humans, but are postnatal events in rats. Major differences in the timing of the developmental sequence between rats and humans include: gonocyte transformation period (rat: postnatal day 0-9; human: includes gestational week 22 to 9 months of age); masculinization programming window (rat: gestational day 15.5-17.5; human: gestational week 9-14); and mini-puberty (rat: 0-6 hr after birth; human: 3-6 months of age). Endocrine disruptors can cause unique lesions in the prenatal and early postnatal testis; therefore, it is important to consider the differences in the timing of the developmental sequence when designing preclinical studies as identification of windows of sensitivity for endocrine disruption or toxicants will aid in interpretation of results and provide clues to a mode of action. Birth Defects Research 110:190-227, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Catherine A Picut
- Charles River Laboratories, Pathology Associates, Durham, North Carolina
| | - Mary K Ziejewski
- GlaxoSmithKline Research & Development, King of Prussia, Pennsylvania
| | - D Stanislaus
- GlaxoSmithKline Research & Development, King of Prussia, Pennsylvania
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18
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Sharma S, Portela JMD, Langenstroth-Röwer D, Wistuba J, Neuhaus N, Schlatt S. Male germline stem cells in non-human primates. Primate Biol 2017; 4:173-184. [PMID: 32110705 PMCID: PMC7041516 DOI: 10.5194/pb-4-173-2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/17/2017] [Indexed: 12/22/2022] Open
Abstract
Over the past few decades, several studies have attempted to decipher the
biology of mammalian germline stem cells (GSCs). These studies provide
evidence that regulatory mechanisms for germ cell specification and migration
are evolutionarily conserved across species. The characteristics and
functions of primate GSCs are highly distinct from rodent species; therefore
the findings from rodent models cannot be extrapolated to primates. Due to
limited availability of human embryonic and testicular samples for research
purposes, two non-human primate models (marmoset and macaque monkeys) are
extensively employed to understand human germline development and
differentiation. This review provides a broader introduction to the in vivo
and in vitro germline stem cell terminology from primordial to
differentiating germ cells. Primordial germ cells (PGCs) are the most
immature germ cells colonizing the gonad prior to sex differentiation into
testes or ovaries. PGC specification and migratory patterns among different
primate species are compared in the review. It also reports the distinctions
and similarities in expression patterns of pluripotency markers (OCT4A,
NANOG, SALL4 and LIN28) during embryonic developmental stages, among
marmosets, macaques and humans. This review presents a comparative summary
with immunohistochemical and molecular evidence of germ cell marker
expression patterns during postnatal developmental stages, among humans and
non-human primates. Furthermore, it reports findings from the recent
literature investigating the plasticity behavior of germ cells and stem cells
in other organs of humans and monkeys. The use of non-human primate models
would enable bridging the knowledge gap in primate GSC research and
understanding the mechanisms involved in germline development. Reported
similarities in regulatory mechanisms and germ cell expression profile in
primates demonstrate the preclinical significance of monkey models for
development of human fertility preservation strategies.
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Affiliation(s)
- Swati Sharma
- Center of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Medicine, Albert Schweitzer Campus 1, Building D11, Münster, Germany.,These authors contributed equally to this work
| | - Joana M D Portela
- Center for Reproductive Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands.,These authors contributed equally to this work
| | - Daniel Langenstroth-Röwer
- Center of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Medicine, Albert Schweitzer Campus 1, Building D11, Münster, Germany
| | - Joachim Wistuba
- Center of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Medicine, Albert Schweitzer Campus 1, Building D11, Münster, Germany
| | - Nina Neuhaus
- Center of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Medicine, Albert Schweitzer Campus 1, Building D11, Münster, Germany
| | - Stefan Schlatt
- Center of Reproductive Medicine and Andrology, Institute of Reproductive and Regenerative Medicine, Albert Schweitzer Campus 1, Building D11, Münster, Germany
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19
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20
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21
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Langenstroth-Röwer D, Gromoll J, Wistuba J, Tröndle I, Laurentino S, Schlatt S, Neuhaus N. De novo methylation in male germ cells of the common marmoset monkey occurs during postnatal development and is maintained in vitro. Epigenetics 2016; 12:527-539. [PMID: 27786608 DOI: 10.1080/15592294.2016.1248007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
The timing of de novo DNA methylation in male germ cells during human testicular development is yet unsolved. Apart from that, the stability of established imprinting patterns in vitro is controversially discussed. This study aimed at determining the timing of DNA de novo methylation and at assessing the stability of the methylation status in vitro. We employed the marmoset monkey (Callithrix jacchus) as it is considered the best non-human primate model for human testicular development. We selected neonatal, pre-pubertal, pubertal, and adult animals (n = 3, each) and assessed germ cell global DNA methylation levels by 5-methyl cytosine staining, and Alu elements and gene-specific methylation (H19, LIT1, SNRPN, MEST, OCT4, MAGE-A4, and DDX-4) by pyrosequencing. De novo methylation is progressively established during postnatal primate development and continues until adulthood, a process that is different in most other species. Importantly, once established, methylation patterns remained stable, as demonstrated using in vitro cultures. Thus, the marmoset monkey is a unique model for the study of postnatal DNA methylation mechanisms in germ cells and for the identification of epimutations and their causes.
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Affiliation(s)
| | - Jörg Gromoll
- a Centre of Reproductive Medicine and Andrology , Albert-Schweitzer-Campus 1, Münster , Germany
| | - Joachim Wistuba
- a Centre of Reproductive Medicine and Andrology , Albert-Schweitzer-Campus 1, Münster , Germany
| | - Ina Tröndle
- a Centre of Reproductive Medicine and Andrology , Albert-Schweitzer-Campus 1, Münster , Germany
| | - Sandra Laurentino
- a Centre of Reproductive Medicine and Andrology , Albert-Schweitzer-Campus 1, Münster , Germany
| | - Stefan Schlatt
- a Centre of Reproductive Medicine and Andrology , Albert-Schweitzer-Campus 1, Münster , Germany
| | - Nina Neuhaus
- a Centre of Reproductive Medicine and Andrology , Albert-Schweitzer-Campus 1, Münster , Germany
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22
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Westernströer B, Langenstroth D, Kliesch S, Troppmann B, Redmann K, Macdonald J, Mitchell R, Wistuba J, Schlatt S, Neuhaus N. Developmental expression patterns of chemokines CXCL11, CXCL12 and their receptor CXCR7 in testes of common marmoset and human. Cell Tissue Res 2015; 361:885-98. [PMID: 25810367 DOI: 10.1007/s00441-015-2164-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 02/24/2015] [Indexed: 01/07/2023]
Abstract
The chemokine receptor CXCR7 interacts with the chemokines CXCL11 and CXCL12. During development, this ligand receptor system (C-X-C) provokes cell-type-specific responses in terms of migration, adhesion or ligand sequestration. It is active in zebrafish and rodents but no data are available for its presence or function in primate testes. Real-time quantitative polymerase chain reaction was performed in monkeys to detect CXCL11, CXCL12 and CXCR7. At the protein level, CXCL12 and CXCR7 were localized in the testes of the marmoset (Callitrix jacchus) whereas CXCR7 patterns were determined for various stages in human testes. Morphometry and flow cytometry were applied to quantify CXCR7-positive cells in monkeys. Transcript levels and protein expression of CXCR7 were detectable throughout testicular development. In both species, CXCR7 protein expression was restricted to premeiotic germ cells. In immature marmoset testes, 69.9% ± 9% of the total germ cell population were labelled for CXCR7, whereas in the adult, 4.7% ± 2.7% were positive for CXCR7. CXCL12 mRNA was detectable in all developmental stages in marmosets. The CXCL12 protein was exclusively localized to Sertoli cells. This pattern of CXCL12/CXCR7 indicates their involvement in regulatory processes that possibly orchestrate the interaction between undifferentiated germ cells and Sertoli cells.
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Affiliation(s)
- Birgit Westernströer
- Centre of Reproductive Medicine and Andrology, CeRA, Institute of Reproductive and Regenerative Biology, Albert-Schweizer-Campus 1, Building D11, 48149, Münster, Germany
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23
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Manku G, Culty M. Mammalian gonocyte and spermatogonia differentiation: recent advances and remaining challenges. Reproduction 2015; 149:R139-57. [DOI: 10.1530/rep-14-0431] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The production of spermatozoa relies on a pool of spermatogonial stem cells (SSCs), formed in infancy from the differentiation of their precursor cells, the gonocytes. Throughout adult life, SSCs will either self-renew or differentiate, in order to maintain a stem cell reserve while providing cells to the spermatogenic cycle. By contrast, gonocytes represent a transient and finite phase of development leading to the formation of SSCs or spermatogonia of the first spermatogenic wave. Gonocyte development involves phases of quiescence, cell proliferation, migration, and differentiation. Spermatogonia, on the other hand, remain located at the basement membrane of the seminiferous tubules throughout their successive phases of proliferation and differentiation. Apoptosis is an integral part of both developmental phases, allowing for the removal of defective cells and the maintenance of proper germ–Sertoli cell ratios. While gonocytes and spermatogonia mitosis are regulated by distinct factors, they both undergo differentiation in response to retinoic acid. In contrast to postpubertal spermatogenesis, the early steps of germ cell development have only recently attracted attention, unveiling genes and pathways regulating SSC self-renewal and proliferation. Yet, less is known on the mechanisms regulating differentiation. The processes leading from gonocytes to spermatogonia have been seldom investigated. While the formation of abnormal gonocytes or SSCs could lead to infertility, defective gonocyte differentiation might be at the origin of testicular germ cell tumors. Thus, it is important to better understand the molecular mechanisms regulating these processes. This review summarizes and compares the present knowledge on the mechanisms regulating mammalian gonocyte and spermatogonial differentiation.
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24
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van den Driesche S, McKinnell C, Calarrão A, Kennedy L, Hutchison GR, Hrabalkova L, Jobling MS, Macpherson S, Anderson RA, Sharpe RM, Mitchell RT. Comparative effects of di(n-butyl) phthalate exposure on fetal germ cell development in the rat and in human fetal testis xenografts. ENVIRONMENTAL HEALTH PERSPECTIVES 2015; 123:223-30. [PMID: 25514601 PMCID: PMC4348744 DOI: 10.1289/ehp.1408248] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Accepted: 12/12/2014] [Indexed: 05/02/2023]
Abstract
BACKGROUND Phthalate exposure induces germ cell effects in the fetal rat testis. Although experimental models have shown that the human fetal testis is insensitive to the steroidogenic effects of phthalates, the effects on germ cells have been less explored. OBJECTIVES We sought to identify the effects of phthalate exposure on human fetal germ cells in a dynamic model and to establish whether the rat is an appropriate model for investigating such effects. METHODS We used immunohistochemistry, immunofluorescence, and quantitative real-time polymerase chain reaction to examine Sertoli and germ cell markers on rat testes and human fetal testis xenografts after exposure to vehicle or di(n-butyl) phthalate (DBP). Our study included analysis of germ cell differentiation markers, proliferation markers, and cell adhesion proteins. RESULTS In both rat and human fetal testes, DBP exposure induced similar germ cell effects, namely, germ cell loss (predominantly undifferentiated), induction of multinucleated gonocytes (MNGs), and aggregation of differentiated germ cells, although the latter occurred rarely in the human testes. The mechanism for germ cell aggregation and MNG induction appears to be loss of Sertoli cell-germ cell membrane adhesion, probably due to Sertoli cell microfilament redistribution. CONCLUSIONS Our findings provide the first comparison of DBP effects on germ cell number, differentiation, and aggregation in human testis xenografts and in vivo in rats. We observed comparable effects on germ cells in both species, but the effects in the human were muted compared with those in the rat. Nevertheless, phthalate effects on germ cells have potential implications for the next generation, which merits further study. Our results indicate that the rat is a human-relevant model in which to explore the mechanisms for germ cell effects.
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Affiliation(s)
- Sander van den Driesche
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
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25
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Lin ZYC, Hirano T, Shibata S, Seki NM, Kitajima R, Sedohara A, Siomi MC, Sasaki E, Siomi H, Imamura M, Okano H. Gene expression ontogeny of spermatogenesis in the marmoset uncovers primate characteristics during testicular development. Dev Biol 2015; 400:43-58. [PMID: 25624265 DOI: 10.1016/j.ydbio.2015.01.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 01/14/2015] [Accepted: 01/16/2015] [Indexed: 10/24/2022]
Abstract
Mammalian spermatogenesis has been investigated extensively in rodents and a strictly controlled developmental process has been defined at cellular and molecular levels. In comparison, primate spermatogenesis has been far less well characterized. However, important differences between primate and rodent spermatogenesis are emerging so it is not always accurate to extrapolate findings in rodents to primate systems. Here, we performed an extensive immunofluorescence study of spermatogenesis in neonatal, juvenile, and adult testes in the common marmoset (Callithrix jacchus) to determine primate-specific patterns of gene expression that underpin primate germ cell development. Initially we characterized adult spermatogonia into two main classes; mitotically active C-KIT(+)Ki67(+) cells and mitotically quiescent SALL4(+)PLZF(+)LIN28(+)DPPA4(+) cells. We then explored the expression of a set of markers, including PIWIL1/MARWI, VASA, DAZL, CLGN, RanBPM, SYCP1 and HAPRIN, during germ cell differentiation from early spermatocytes through round and elongating spermatids, and a clear program of gene expression changes was determined as development proceeded. We then examined the juvenile marmoset testis. Markers of gonocytes demonstrated two populations; one that migrates to the basal membrane where they form the SALL4(+) or C-KIT(+) spermatogonia, and another that remains in the lumen of the seminiferous tubule. This later population, historically identified as pre-spermatogonia, expressed meiotic and apoptotic markers and were eliminated because they appear to have failed to correctly migrate. Our findings provide the first platform of gene expression dynamics in adult and developing germ cells of the common marmoset. Although we have characterized a limited number of genes, these results will facilitate primate spermatogenesis research and understanding of human reproduction.
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Affiliation(s)
- Zachary Yu-Ching Lin
- Department of Physiology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Takamasa Hirano
- Department of Molecular Biology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Shinsuke Shibata
- Department of Physiology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Naomi M Seki
- Department of Molecular Biology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ryunosuke Kitajima
- Molecular Biology Section, Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan
| | - Ayako Sedohara
- Department of Applied Developmental Biology, Central Institute for Experimental Animals, 3-25-12 Tonomachi, Kawasaki 210-0821, Japan
| | - Mikiko C Siomi
- Department of Molecular Biology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Erika Sasaki
- Department of Physiology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan; Department of Applied Developmental Biology, Central Institute for Experimental Animals, 3-25-12 Tonomachi, Kawasaki 210-0821, Japan; PRESTO Japan Science and Technology Agency, Japan
| | - Haruhiko Siomi
- Department of Molecular Biology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Masanori Imamura
- Department of Physiology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan; Molecular Biology Section, Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan.
| | - Hideyuki Okano
- Department of Physiology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
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Aeckerle N, Drummer C, Debowski K, Viebahn C, Behr R. Primordial germ cell development in the marmoset monkey as revealed by pluripotency factor expression: suggestion of a novel model of embryonic germ cell translocation. Mol Hum Reprod 2014; 21:66-80. [PMID: 25237007 PMCID: PMC4275041 DOI: 10.1093/molehr/gau088] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Primordial germ cells (PGCs) are the embryonic progenitors of sperm and egg cells. Mammalian PGCs are thought to actively migrate from the yolk sac endoderm over long distances across the embryo to reach the somatic genital ridges. The general principles of mammalian PGC development were discovered in mice. In contrast, little is known about PGC development in primates due to extremely limited access to primate embryos. Here, we analyzed 12 well preserved marmoset monkey (Callithrix jacchus) embryos covering the phase from PGC emergence in the endoderm to the formation of the sexually differentiated gonad (embryonic day (E) 50 to E95). We show using immunohistochemistry that the pluripotency factors OCT4A and NANOG specifically mark PGCs throughout the period studied. In contrast, SALL4 and LIN28 were first expressed ubiquitously and only later down-regulated in somatic tissues. We further show, for the first time, that PGCs are located in the endoderm in E50 embryos in close spatial proximity to the prospective genital ridge, making a long-range migration of PGCs dispensable. At E65, PGCs are already present in the primitive gonad, while significantly later embryonic stages still exhibit PGCs at their original endodermal site, revealing a wide spatio-temporal window of PGC distribution. Our findings challenge the ‘dogma’ of active long-range PGC migration from the endoderm to the gonads. We therefore favor an alternative model based primarily on passive translocation of PGCs from the mesenchyme that surrounds the gut to the prospective gonad through the intercalar expansion of mesenchymal tissue which contains the PGCs. In summary, we (i) show differential pluripotency factor expression during primate embryo development and (ii) provide a schematic model for embryonic PGC translocation.
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Affiliation(s)
- N Aeckerle
- Stem Cell Biology Unit, German Primate Center - Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - C Drummer
- Stem Cell Biology Unit, German Primate Center - Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - K Debowski
- Stem Cell Biology Unit, German Primate Center - Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - C Viebahn
- Department of Anatomy and Embryology, Center of Anatomy, University of Göttingen, Kreuzbergring 36, 37075 Göttingen, Germany
| | - R Behr
- Stem Cell Biology Unit, German Primate Center - Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
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Langenstroth D, Kossack N, Westernströer B, Wistuba J, Behr R, Gromoll J, Schlatt S. Separation of somatic and germ cells is required to establish primate spermatogonial cultures. Hum Reprod 2014; 29:2018-31. [PMID: 24963164 DOI: 10.1093/humrep/deu157] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
STUDY QUESTION Can primate spermatogonial cultures be optimized by application of separation steps and well defined culture conditions? SUMMARY ANSWER We identified the cell fraction which provides the best source for primate spermatogonia when prolonged culture is desired. WHAT IS KNOWN ALREADY Man and marmoset show similar characteristics in regard to germ cell development and function. Several protocols for isolation and culture of human testis-derived germline stem cells have been described. Subsequent analysis revealed doubts on the germline origin of these cells and characterized them as mesenchymal stem cells or fibroblasts. Studies using marmosets as preclinical model confirmed that the published isolation protocols did not lead to propagation of germline cells. STUDY DESIGN, SIZE, DURATION Testicular cells derived from nine adult marmoset monkeys (Callithrix jacchus) were cultured for 1, 3, 6 and 11 days and consecutively analyzed for the presence of spermatogonia, differentiating germ cells and testicular somatic cells. PARTICIPANTS/MATERIALS, SETTING, METHODS Testicular tissue of nine adult marmoset monkeys was enzymatically dissociated and subjected to two different cell culture approaches. In the first approach all cells were kept in the same dish (non-separate culture, n = 5). In the second approach the supernatant cells were transferred into a new dish 24 h after seeding and subsequently supernatant and attached cells were cultured separately (separate culture, n = 4). Real-time quantitative PCR and immunofluorescence were used to analyze the expression of reliable germ cell and somatic markers throughout the culture period. Germ cell transplantation assays and subsequent wholemount analyses were performed to functionally evaluate the colonization of spermatogonial cells. MAIN RESULTS AND THE ROLE OF CHANCE This is the first report revealing an efficient isolation and culture of putative marmoset spermatogonial stem cells with colonization ability. Our results indicate that a separation of spermatogonia from testicular somatic cells is a crucial step during cell preparation. We identified the overgrowth of more rapidly expanding somatic cells to be a major problem when establishing spermatogonial cultures. Initiating germ cell cultures from the supernatant and maintaining germ cells in suspension cultures minimized the somatic cell contamination and provided enriched germ cell fractions which displayed after 11 days of culture a significantly higher expression of germ cell markers genes (DDX-4, MAGE A-4; P < 0.05) compared with separately cultured attached cells. Additionally, germ cell transplantation experiments demonstrated a significantly higher absolute number of cells with colonization ability (P < 0.001) in supernatant cells after 11 days of separate culture. LIMITATIONS, REASONS FOR CAUTION This study presents a relevant aspect for the successful setup of spermatogonial cultures but provides limited data regarding the question of whether the long-term maintenance of spermatogonia can be achieved. Transfer of these preclinical data to man may require modifications of the protocol. WIDER IMPLICATIONS OF THE FINDINGS Spermatogonial cultures from rodents have become important and innovative tools for basic and applied research in reproductive biology and veterinary medicine. It is expected that spermatogonia-based strategies will be transformed into clinical applications for the treatment of male infertility. Our data in the marmoset monkey may be highly relevant to establish spermatogonial cultures of human testes. STUDY FUNDING/COMPETING INTERESTS Funding was provided by the DFG-Research Unit FOR 1041 Germ Cell Potential (SCHL394/11-2) and by the Graduate Program Cell Dynamics and Disease (CEDAD) together with the International Max Planck Research School - Molecular Biomedicine (IMPRS-MBM). The authors declare that there is no conflict of interest. TRIAL REGISTRATION NUMBER Not applicable.
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Affiliation(s)
- Daniel Langenstroth
- Institute of Reproduction and Regenerative Biology, Centre of Reproductive Medicine and Andrology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
| | - Nina Kossack
- Institute of Reproduction and Regenerative Biology, Centre of Reproductive Medicine and Andrology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
| | - Birgit Westernströer
- Institute of Reproduction and Regenerative Biology, Centre of Reproductive Medicine and Andrology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
| | - Joachim Wistuba
- Institute of Reproduction and Regenerative Biology, Centre of Reproductive Medicine and Andrology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
| | - Rüdiger Behr
- Stem Cell Biology Unit, German Primate Center, Kellnerweg 4, 37077 Göttingen, Germany
| | - Jörg Gromoll
- Institute of Reproduction and Regenerative Biology, Centre of Reproductive Medicine and Andrology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
| | - Stefan Schlatt
- Institute of Reproduction and Regenerative Biology, Centre of Reproductive Medicine and Andrology, Albert-Schweitzer-Campus 1, Building D11, 48149 Münster, Germany
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Fereydouni B, Drummer C, Aeckerle N, Schlatt S, Behr R. The neonatal marmoset monkey ovary is very primitive exhibiting many oogonia. Reproduction 2014; 148:237-47. [PMID: 24840529 PMCID: PMC4086814 DOI: 10.1530/rep-14-0068] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Oogonia are characterized by diploidy and mitotic proliferation. Human and mouse oogonia express several factors such as OCT4, which are characteristic of pluripotent cells. In human, almost all oogonia enter meiosis between weeks 9 and 22 of prenatal development or undergo mitotic arrest and subsequent elimination from the ovary. As a consequence, neonatal human ovaries generally lack oogonia. The same was found in neonatal ovaries of the rhesus monkey, a representative of the old world monkeys (Catarrhini). By contrast, proliferating oogonia were found in adult prosimians (now called Strepsirrhini), which is a group of ‘lower’ primates. The common marmoset monkey (Callithrix jacchus) belongs to the new world monkeys (Platyrrhini) and is increasingly used in reproductive biology and stem cell research. However, ovarian development in the marmoset monkey has not been widely investigated. Herein, we show that the neonatal marmoset ovary has an extremely immature histological appearance compared with the human ovary. It contains numerous oogonia expressing the pluripotency factors OCT4A, SALL4, and LIN28A (LIN28). The pluripotency factor-positive germ cells also express the proliferation marker MKI67 (Ki-67), which has previously been shown in the human ovary to be restricted to premeiotic germ cells. Together, the data demonstrate the primitiveness of the neonatal marmoset ovary compared with human. This study may introduce the marmoset monkey as a non-human primate model to experimentally study the aspects of primate primitive gonad development, follicle assembly, and germ cell biology in vivo.
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Affiliation(s)
- B Fereydouni
- Stem Cell Biology UnitGerman Primate Center - Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, GermanyCentre of Reproductive Medicine and AndrologyUniversity of Münster, Domagkstraße 11, 48149 Münster, Germany
| | - C Drummer
- Stem Cell Biology UnitGerman Primate Center - Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, GermanyCentre of Reproductive Medicine and AndrologyUniversity of Münster, Domagkstraße 11, 48149 Münster, Germany
| | - N Aeckerle
- Stem Cell Biology UnitGerman Primate Center - Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, GermanyCentre of Reproductive Medicine and AndrologyUniversity of Münster, Domagkstraße 11, 48149 Münster, Germany
| | - S Schlatt
- Stem Cell Biology UnitGerman Primate Center - Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, GermanyCentre of Reproductive Medicine and AndrologyUniversity of Münster, Domagkstraße 11, 48149 Münster, Germany
| | - R Behr
- Stem Cell Biology UnitGerman Primate Center - Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, GermanyCentre of Reproductive Medicine and AndrologyUniversity of Münster, Domagkstraße 11, 48149 Münster, Germany
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