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Chen Y, Fang X, Tian XQ, Cui Z, Feng HY, Qiu GF. Germ plasm and the origin of the primordial germ cells in the oriental river prawn Macrobrachium nipponense. Cell Tissue Res 2021; 386:559-569. [PMID: 34599688 DOI: 10.1007/s00441-021-03534-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 09/21/2021] [Indexed: 11/28/2022]
Abstract
Germ plasm is a special cytoplasmic component containing special RNAs and proteins, and is located in specific regions of oocytes and embryos. Only the blastomeres inheriting the germ plasm can develop into primordial germ cells (PGCs). By using Vasa mRNA as a germline marker, we previously demonstrated that germline specification followed the preformation mode in the prawn Macrobrachium nipponense. In this study, we raised the Vasa antibody to identify germ plasm in the oocyte and trace the origin and migration of PGCs. In previtellogenic oocytes, Vasa protein was detected in the perinuclear region, in which electron-dense granules associated with numerous mitochondria were mostly visualized under a transmission electron microscope. In mature oocytes, immunosignal was localized to a large granule under the plasma membrane. During early embryogenesis, the granule was inherited by a single blastomere from 1-cell to 16-cell stages, and thereafter was segregated into two daughter blastomeres at the 32-cell stage. In gastrula, the Vasa-positive cells were large with typical PGC characteristics, containing a big round nucleus and a prominent nucleolus. The immunosignal was localized to the perinuclear region again. In the zoea stage, the Vasa-positive cells migrated toward the genital ridge and clustered in the dorsomedial region close to the yolk portion. Accordingly, we concluded that the prawn PGCs could be specified from the 16-cell stage by inheriting the germplasm. To our knowledge, this is the first report on the identification of the prawn germ plasm and PGCs. The continuous expression of Vasa protein throughout oogenesis and embryogenesis suggests that Vasa protein could be an important factor in germ plasm that functions in early germ cell specification.
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Affiliation(s)
- Ying Chen
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture; National Demonstration Center for Experimental Fisheries Science Education; Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, 999 Hucheng Ring Road, Shanghai, 201306, China
| | - Xiang Fang
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture; National Demonstration Center for Experimental Fisheries Science Education; Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, 999 Hucheng Ring Road, Shanghai, 201306, China
| | - Xiao-Qing Tian
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture; National Demonstration Center for Experimental Fisheries Science Education; Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, 999 Hucheng Ring Road, Shanghai, 201306, China
| | - Zheng Cui
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture; National Demonstration Center for Experimental Fisheries Science Education; Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, 999 Hucheng Ring Road, Shanghai, 201306, China
| | - Hai-Yang Feng
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture; National Demonstration Center for Experimental Fisheries Science Education; Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, 999 Hucheng Ring Road, Shanghai, 201306, China
| | - Gao-Feng Qiu
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture; National Demonstration Center for Experimental Fisheries Science Education; Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, 999 Hucheng Ring Road, Shanghai, 201306, China.
- College of Fisheries and Life Science, Pudong New Area, Shanghai Ocean University, 999 Hucheng Ring Road, Shanghai, 201306, China.
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Cook LE, Finger BJ, Green MP, Pask AJ. Exposure to atrazine during puberty reduces sperm viability, increases weight gain and alters the expression of key metabolic genes in the liver of male mice. Reprod Fertil Dev 2020; 31:920-931. [PMID: 30636190 DOI: 10.1071/rd18505] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 12/16/2018] [Indexed: 12/14/2022] Open
Abstract
Atrazine (ATZ) is one of the most widely used herbicides worldwide and is a common contaminant in human drinking water. It disrupts metabolic pathways in plants, and has metabolic and reproductive effects in vertebrates, including humans. Few studies have investigated the effects of exposure to low doses of ATZ, especially during sexual development in males. In this study, we exposed C57BL/6J male mice from weaning for 8 weeks to drinking water containing 0.5mgkg-1 bodyweight (BW) day-1 ATZ, the 'no observed effect' level used by the Australian government, or a 10-fold higher dose (5mgkg-1 BW day-1). Mice treated with the low dose of ATZ showed increased total and cumulative weight gain. At 12 weeks of age, there was a significant increase in the percentage of dead spermatozoa in both ATZ-exposed groups, as well as decreased epididymal sperm motility in the low-dose ATZ group. Significant changes in testis and liver gene expression were also observed following ATZ exposure. These data demonstrate that a low dose of ATZ can perturb metabolic and reproductive characteristics in male mice. A chronic reduction in sperm quality and increased weight gain could have negative consequences on the reproductive capacity of males, and further studies should consider the effects of long-term ATZ exposure on male reproductive health.
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Affiliation(s)
- Laura E Cook
- School of BioSciences, The University of Melbourne, Melbourne, Vic. 3010, Australia
| | - Bethany J Finger
- School of BioSciences, The University of Melbourne, Melbourne, Vic. 3010, Australia
| | - Mark P Green
- School of BioSciences, The University of Melbourne, Melbourne, Vic. 3010, Australia
| | - Andrew J Pask
- School of BioSciences, The University of Melbourne, Melbourne, Vic. 3010, Australia
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Grimaldi C, Raz E. Germ cell migration-Evolutionary issues and current understanding. Semin Cell Dev Biol 2019; 100:152-159. [PMID: 31864795 DOI: 10.1016/j.semcdb.2019.11.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 11/25/2019] [Accepted: 11/27/2019] [Indexed: 11/19/2022]
Abstract
In many organisms, primordial germ cells (PGCs) are specified at a different location than where the gonad forms, meaning that PGCs must migrate toward the gonad within the early developing embryo. Following species-specific paths, PGCs can be passively carried by surrounding tissues and also perform active migration. When PGCs actively migrate through and along a variety of embryonic structures in different organisms, they adopt an ancestral robust migration mode termed "amoeboid motility", which allows cells to migrate within diverse environments. In this review, we discuss the possible significance of the PGC migration process in facilitating the evolution of animal body shape. In addition, we summarize the latest findings relevant for the molecular and cellular mechanisms controlling the movement and the directed migration of PGCs in different species.
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Affiliation(s)
- Cecilia Grimaldi
- Institute of Cell Biology, Center for Molecular Biology of Inflammation, University of Münster, Münster, 48149, Germany
| | - Erez Raz
- Institute of Cell Biology, Center for Molecular Biology of Inflammation, University of Münster, Münster, 48149, Germany.
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Grey C, Espeut J, Ametsitsi R, Kumar R, Luksza M, Brun C, Verlhac MH, Suja JA, de Massy B. SKAP, an outer kinetochore protein, is required for mouse germ cell development. Reproduction 2015; 151:239-51. [PMID: 26667018 PMCID: PMC4738695 DOI: 10.1530/rep-15-0451] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 12/14/2015] [Indexed: 11/08/2022]
Abstract
In sexually reproducing organisms, accurate gametogenesis is crucial for the transmission of genetic material from one generation to the next. This requires the faithful segregation of chromosomes during mitotic and meiotic divisions. One of the main players in this process is the kinetochore, a large multi-protein complex that forms at the interface of centromeres and microtubules. Here, we analyzed the expression profile and function of small kinetochore-associated protein (SKAP) in the mouse. We found that two distinct SKAP isoforms are specifically expressed in the germline: a smaller isoform, which is detected in spermatogonia and spermatocytes and localized in the outer mitotic and meiotic kinetochores from metaphase to telophase, and a larger isoform, which is expressed in the cytoplasm of elongating spermatids. We generated SKAP-deficient mice and found that testis size and sperm production were severely reduced in mutant males. This phenotype was partially caused by defects during spermatogonia proliferation before entry into meiosis. We conclude that mouse SKAP, while being dispensable for somatic cell divisions, has an important role in the successful outcome of male gametogenesis. In germ cells, analogous to what has been suggested in studies using immortalized cells, SKAP most likely stabilizes the interaction between kinetochores and microtubules, where it might be needed as an extra safeguard to ensure the correct segregation of mitotic and meiotic chromosomes.
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Affiliation(s)
- Corinne Grey
- CNRSIGH (UPR1142), 141 rue de la Cardonille, 34396 Montpellier, FranceCNRSCRBM (UMR5237), 1919 route de Mende, 34293 Montpellier, FranceINRADépartement Biologie et Amélioration des Plantes, route de Saint-Cyr, 78026 Versailles, FranceCollège de FranceCIRB (UMR CNRS 7241/INSERM- U1050), 11 Place Marcelin Berthelot, 75005 Paris, FranceDepartamento de BiologíaFacultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Julien Espeut
- CNRSIGH (UPR1142), 141 rue de la Cardonille, 34396 Montpellier, FranceCNRSCRBM (UMR5237), 1919 route de Mende, 34293 Montpellier, FranceINRADépartement Biologie et Amélioration des Plantes, route de Saint-Cyr, 78026 Versailles, FranceCollège de FranceCIRB (UMR CNRS 7241/INSERM- U1050), 11 Place Marcelin Berthelot, 75005 Paris, FranceDepartamento de BiologíaFacultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Rachel Ametsitsi
- CNRSIGH (UPR1142), 141 rue de la Cardonille, 34396 Montpellier, FranceCNRSCRBM (UMR5237), 1919 route de Mende, 34293 Montpellier, FranceINRADépartement Biologie et Amélioration des Plantes, route de Saint-Cyr, 78026 Versailles, FranceCollège de FranceCIRB (UMR CNRS 7241/INSERM- U1050), 11 Place Marcelin Berthelot, 75005 Paris, FranceDepartamento de BiologíaFacultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Rajeev Kumar
- CNRSIGH (UPR1142), 141 rue de la Cardonille, 34396 Montpellier, FranceCNRSCRBM (UMR5237), 1919 route de Mende, 34293 Montpellier, FranceINRADépartement Biologie et Amélioration des Plantes, route de Saint-Cyr, 78026 Versailles, FranceCollège de FranceCIRB (UMR CNRS 7241/INSERM- U1050), 11 Place Marcelin Berthelot, 75005 Paris, FranceDepartamento de BiologíaFacultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Malgorzata Luksza
- CNRSIGH (UPR1142), 141 rue de la Cardonille, 34396 Montpellier, FranceCNRSCRBM (UMR5237), 1919 route de Mende, 34293 Montpellier, FranceINRADépartement Biologie et Amélioration des Plantes, route de Saint-Cyr, 78026 Versailles, FranceCollège de FranceCIRB (UMR CNRS 7241/INSERM- U1050), 11 Place Marcelin Berthelot, 75005 Paris, FranceDepartamento de BiologíaFacultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Christine Brun
- CNRSIGH (UPR1142), 141 rue de la Cardonille, 34396 Montpellier, FranceCNRSCRBM (UMR5237), 1919 route de Mende, 34293 Montpellier, FranceINRADépartement Biologie et Amélioration des Plantes, route de Saint-Cyr, 78026 Versailles, FranceCollège de FranceCIRB (UMR CNRS 7241/INSERM- U1050), 11 Place Marcelin Berthelot, 75005 Paris, FranceDepartamento de BiologíaFacultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Marie-Hélene Verlhac
- CNRSIGH (UPR1142), 141 rue de la Cardonille, 34396 Montpellier, FranceCNRSCRBM (UMR5237), 1919 route de Mende, 34293 Montpellier, FranceINRADépartement Biologie et Amélioration des Plantes, route de Saint-Cyr, 78026 Versailles, FranceCollège de FranceCIRB (UMR CNRS 7241/INSERM- U1050), 11 Place Marcelin Berthelot, 75005 Paris, FranceDepartamento de BiologíaFacultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - José Angél Suja
- CNRSIGH (UPR1142), 141 rue de la Cardonille, 34396 Montpellier, FranceCNRSCRBM (UMR5237), 1919 route de Mende, 34293 Montpellier, FranceINRADépartement Biologie et Amélioration des Plantes, route de Saint-Cyr, 78026 Versailles, FranceCollège de FranceCIRB (UMR CNRS 7241/INSERM- U1050), 11 Place Marcelin Berthelot, 75005 Paris, FranceDepartamento de BiologíaFacultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Bernard de Massy
- CNRSIGH (UPR1142), 141 rue de la Cardonille, 34396 Montpellier, FranceCNRSCRBM (UMR5237), 1919 route de Mende, 34293 Montpellier, FranceINRADépartement Biologie et Amélioration des Plantes, route de Saint-Cyr, 78026 Versailles, FranceCollège de FranceCIRB (UMR CNRS 7241/INSERM- U1050), 11 Place Marcelin Berthelot, 75005 Paris, FranceDepartamento de BiologíaFacultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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Dutta S, Mark-Kappeler CJ, Hoyer PB, Pepling ME. The Steroid Hormone Environment During Primordial Follicle Formation in
Perinatal Mouse Ovaries1. Biol Reprod 2014; 91:68. [DOI: 10.1095/biolreprod.114.119214] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Affiliation(s)
- Sudipta Dutta
- Department of Biology, Syracuse University, Syracuse, New York
| | | | - Patricia B. Hoyer
- Department of Physiology, College of Medicine, The University of Arizona, Tucson, Arizona
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Mikedis MM, Downs KM. Widespread but tissue-specific patterns of interferon-induced transmembrane protein 3 (IFITM3, FRAGILIS, MIL-1) in the mouse gastrula. Gene Expr Patterns 2013; 13:225-39. [PMID: 23639725 DOI: 10.1016/j.gep.2013.04.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 04/16/2013] [Accepted: 04/19/2013] [Indexed: 10/26/2022]
Abstract
Interferon-induced transmembrane protein 3 (IFITM3; FRAGILIS; MIL-1) is part of a larger family of important small interferon-induced transmembrane genes and proteins involved in early development, cell adhesion, and cell proliferation, and which also play a major role in response to bacterial and viral infections and, more recently, in pronounced malignancies. IFITM3, together with tissue-nonspecific alkaline phosphatase (TNAP), PRDM1, and STELLA, has been claimed to be a hallmark of segregated primordial germ cells (PGCs) (Saitou et al., 2002). However, whether IFITM3, like STELLA, is part of a broader stem/progenitor pool that builds the posterior region of the mouse conceptus (Mikedis and Downs, 2012) is obscure. To discover the whereabouts of IFITM3 during mouse gastrulation (~E6.5-9.0), systematic immunohistochemical analysis was carried out at closely spaced 2-4-h intervals. Results revealed diverse, yet consistent, profiles of IFITM3 localization throughout the gastrula. Within the putative PGC trajectory and surrounding posterior tissues, IFITM3 localized as a large cytoplasmic spot with or without staining in the plasma membrane. IFITM3, like STELLA, was also found in the ventral ectodermal ridge (VER), a posterior progenitor pool that builds the tailbud. The large cytoplasmic spot with plasma membrane staining was exclusive to the posterior region; the visceral yolk sac, non-posterior tissues, and epithelial tissues exhibited spots of IFITM3 without cell surface staining. Colocalization of the intracellular IFITM3 spot with the endoplasmic reticulum, Golgi apparatus, or endolysosomes was not observed. That relatively high levels of IFITM3 were found throughout the posterior primitive streak and its derivatives is consistent with evidence that IFITM3, like STELLA, is part of a larger stem/progenitor cell pool at the posterior end of the primitive streak that forms the base of the allantois and builds the fetal-umbilical connection, thus further obfuscating practical phenotypic distinctions between so-called PGCs and surrounding soma.
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Affiliation(s)
- Maria M Mikedis
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA
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7
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Griswold MD, Oatley JM. Concise review: Defining characteristics of mammalian spermatogenic stem cells. Stem Cells 2013; 31:8-11. [PMID: 23074087 PMCID: PMC5312674 DOI: 10.1002/stem.1253] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 09/25/2012] [Indexed: 01/15/2023]
Abstract
The enormous number of sperms produced daily and over the lifetime of mammals requires a stable source of stem cells that give rise to progenitor cells that proceed through spermatogenesis. Spermatogenic stem cells develop from primitive germ cells that occupy the developing gonad. A transplantation assay was developed for the spermatogenic stem cells, and it remains the only functional measure of authentic stem cells in the testis. Somatic cells comprise a "niche" environment that is essential for the maintenance of stem cell activity. Dividing progenitor cells have intercellular bridges and form syncytia with 2, 4, 8, or 16 cells. Fragmentation of these syncytia may allow some progenitor cells to occupy "niches" and function as stem cells, but this notion requires further investigation. Spermatogenic stem cells can be maintained in culture and are influenced by a number of growth factors. Thus far, the ultimate differentiation of cultured stem cells into functional gametes has not been demonstrated with any efficiency and reproducibility. The ability to maintain spermatogenic stem cells in culture and to induce differentiation into haploid cells and sperm could have many important implications for human medicine.
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Affiliation(s)
- Michael D Griswold
- School of Molecular Biosciences, Center for Reproductive Biology, Washington State University, Pullman, Washington 99164-7520, USA.
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8
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The reciprocal relationship between primordial germ cells and pluripotent stem cells. J Mol Med (Berl) 2012; 90:753-61. [PMID: 22584374 DOI: 10.1007/s00109-012-0912-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 04/03/2012] [Accepted: 05/02/2012] [Indexed: 10/28/2022]
Abstract
Primordial germ cells (PGCs) are induced in the epiblast early in mammalian development. They develop their specific fate separate from somatic cells by the generation of a unique transcriptional profile and by epigenetic modifications of histones and DNA. PGCs are related to pluripotent cells in many respects, both on a molecular and a cell biological level. Mimicking their in vivo development, PGCs can be derived in culture from pluripotent cells. Vice versa, PGCs can be converted in vitro into pluripotent embryonic germ cells. Recent evidence indicates that the derivation of pluripotent embryonic stem cells from explanted inner cell mass cells may pass through a germ cell-like state, but that this intermediate is not obligatory. In this review, we discuss PGC development and its relevance to pluripotency in mammalian embryos. We outline possibilities and problems connected to the application of in vitro-derived germ cells in reproductive medicine.
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Oktem O, Oktay K. Current knowledge in the renewal capability of germ cells in the adult ovary. ACTA ACUST UNITED AC 2009; 87:90-5. [DOI: 10.1002/bdrc.20143] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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10
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Abstract
Stem cells, with their unlimited self-renewal feature and their ability to differentiate into almost every mature cell type in the body, have enormous potential for research and therapeutic application. In this article, we review the formation of primordial germ cells, the precursors of adult gametocytes, from their specification to their migration to prospective gonads. We discuss recent studies that obtained germ cells from stem cells in vitro. We place special emphasis on studies that challenge the current dogma in reproductive biology that female mammals are born with a set number of nonrenewable germ cells in the ovary by showing germ cell renewal in the adult ovary.
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Affiliation(s)
- Ozgur Oktem
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics & Gynecology, New York Medical College, Munger Pavilion Room 617, Valhalla, NY 10595, USA
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Huang X, Andreu-Vieyra CV, York JP, Hatcher R, Lu T, Matzuk MM, Zhang P. Inhibitory phosphorylation of separase is essential for genome stability and viability of murine embryonic germ cells. PLoS Biol 2008; 6:e15. [PMID: 18232736 PMCID: PMC2214812 DOI: 10.1371/journal.pbio.0060015] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Indexed: 11/23/2022] Open
Abstract
Activity of separase, a cysteine protease that cleaves sister chromatid cohesin at the onset of anaphase, is tightly regulated to ensure faithful chromosome segregation and genome stability. Two mechanisms negatively regulate separase: inhibition by securin and phosphorylation on serine 1121. To gauge the physiological significance of the inhibitory phosphorylation, we created a mouse strain in which Ser1121 was mutated to Ala (S1121A). Here we report that this S1121A point mutation causes infertility in mice. We show that germ cells in the mutants are depleted during development. We further demonstrate that S1121A causes chromosome misalignment during proliferation of the postmigratory primordial germ cells, resulting in mitotic arrest, aneuploidy, and eventual cell death. Our results indicate that inhibitory phosphorylation of separase plays a critical role in the maintenance of sister chromatid cohesion and genome stability in proliferating postmigratory primordial germ cells. Higher eukaryotes rely on a separate cell lineage, the germline, to pass genetic information from generation to generation. To ensure faithful transmission of genetic information, cell cycle checkpoint mechanisms are engaged during mitotic and meiotic divisions of germ cells. The identity and function of these checkpoints is not well understood. In mammals, the germline is specified early in embryogenesis as primordial germ cells (PGCs) at the epiblast stage (around embryonic day 5.0 in mice). PGCs then migrate out from their birthplace and arrive at the genital ridge several days later. In the genital ridge, PGCs undergo a great expansion in number through mitosis. During this expansion, PGCs critically depend on the inhibitory phosphorylation of separase to prevent premature separation of sister chromatids and hence progeny with abnormal chromosome number. Separase is a protease which cleaves the Scc1 subunit of sister chromatid cohesin complex. Its activity must be suppressed before all sisters are aligned at the metaphase plate. Two mechanisms are known that can inhibit separase: phosphorylation and binding by securin, both of which are activated at the spindle assembly checkpoint. Although these two mechanisms are redundant in somatic cells, our results indicate that the inhibitory phosphorylation of separase is uniquely required in the germline. A single point mutation of separase that blocks its phosphorylation has a profound and dominant effect on germ cell biology.
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Affiliation(s)
- Xingxu Huang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Claudia V Andreu-Vieyra
- Department of Pathology, Baylor College of Medicine, Houston, Texas, United States of America
| | - J. Philippe York
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Rashieda Hatcher
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Tao Lu
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Martin M Matzuk
- Department of Pathology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Pumin Zhang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- * To whom correspondence should be addressed. E-mail:
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Cronkhite JT, Norlander C, Furth JK, Levan G, Garbers DL, Hammer RE. Male and female germline specific expression of an EGFP reporter gene in a unique strain of transgenic rats. Dev Biol 2005; 284:171-83. [PMID: 15993404 DOI: 10.1016/j.ydbio.2005.05.015] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2005] [Revised: 05/13/2005] [Accepted: 05/16/2005] [Indexed: 12/14/2022]
Abstract
A rat line was generated in which genomic integration of a ROSA-EGFP transgene resulted in exclusive expression of EGFP in the germ cells of both sexes. EGFP expression was uniform and robust in cleavage stage embryos beginning at the late 2-cell stage and continuing through blastocyst development where expression became restricted to cells of the inner cell mass. Subsequent analysis showed high EGFP expression exclusively in primordial, embryonic, and adult germ cells. This unique expression pattern makes this EGFP marked locus the first molecular marker of the germline lineage in both sexes in mammals. FISH was used to localize the transgene insertion to chromosome 11q11-q12, proximal to Grik1 and near Ncam2. Analysis of the region did not identify known germ cell-specific genes but did identify 19 ESTs or transcribed loci present in testes, ovary, or pre-implantation libraries from mice or rats. To assess the utility of the transgenic line for germ cell transplantation studies, non-selected, freshly isolated seminiferous tubule cells were transferred to the testis of recipient males. The donor cell population colonized the testis at a surprisingly high efficiency within 30 days following transfer. Since EGFP is a vital marker, the colonization process can be followed in vivo and the extent of colonization quantified. The unique germ cell specific expression of EGFP makes this line of transgenic rats an excellent novel tool to study germ cell origin, development, and differentiation, and to assess the plasticity of adult somatic stem cells to become male germ cells.
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Affiliation(s)
- Jennifer T Cronkhite
- Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9038, USA
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13
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Abstract
That evolution of longevity may depend on alterations in the expression of relatively few regulatory genes has been inferred from the rapid increase in lifespan during evolution of the hominid species (Cutler RG (1979) Mech Ageing Dev 9: 337-354). Also the inherent immortality of the embryonic stem cells implies that replicative senescence (Hayflick L (1997) Biochem Mosc 62: 1180-1190) as possibly aging of species are epigenetic phenomena. Evidence is presented to suggest that the epigenetic changes of the longevity determinants to a significant extend concerns the molecular chaperones. Specific involvement of RNA chaperones in cell immortalization and defective RecQ-DNA chaperones in syndromes of premature aging suggest that DNA/RNA - chaperones probably rank high among the determinants of cellular and species longevity.
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Affiliation(s)
- J Krøll
- Hafnia Unit of Biogerontology, Godthåbsvej 111,3, DK-2000, Frederiksberg, Denmark.
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Bowles J, Teasdale RP, James K, Koopman P. Dppa3 is a marker of pluripotency and has a human homologue that is expressed in germ cell tumours. Cytogenet Genome Res 2004; 101:261-5. [PMID: 14684992 DOI: 10.1159/000074346] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2003] [Accepted: 09/15/2003] [Indexed: 11/19/2022] Open
Abstract
We identified a transcript named 11M2 on the basis of its strong male-specific expression pattern in the developing mouse gonad. 11M2 was found to be expressed by gonad primordial germ cells (PGCs) of both sexes and down-regulated in female PGCs as they enter prophase I of the first meiotic division, similar to the expression of OCT4. Mouse EST analysis revealed expression only in early-stage embryos, embryonic stem cells and pre-meiotic germ cells. 11M2 corresponds to a recently reported gene variously known as PGC7, STELLA or DPPA3. We have identified the human orthologue of DPPA3 and find by human EST analysis that it is expressed in human testicular germ cell tumours but not in normal human somatic tissues. The expression patterns of mouse and human DPPA3, in undifferentiated embryonic cells, embryonic germ cells and adult germ cell tumours, together suggest a role for this gene in maintaining cell pluripotentiality.
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Affiliation(s)
- J Bowles
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
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15
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Abstract
During the peri-implantation development of the mouse embryo from the blastocyst through gastrulation, Pou5f1 (OCT-4) down-regulation is closely linked to the initial step of lineage allocation to extraembryonic and embryonic somatic tissues. Subsequently, differentiation of the lineage precursors is subject to inductive tissue interactions and intercellular signalling that regulate cell proliferation and the acquisition of lineage-specific morphological and molecular characteristics. A notable variation of this process of lineage specification is the persistence of Pou5f1 activity throughout the differentiation of the primordial germ cells, which may underpin their ability to produce pluripotent progeny either as stem cells (embryonic germ cells) in vitro or as gametes in vivo. Nevertheless, intercellular signalling still plays a critical role in the specification of the primordial germ cells. The findings that primordial germ cells can be induced from any epiblast cells and that they share common progenitors with other somatic cells provide compelling evidence for the absence of a pre-determined germ line in the mouse embryo.
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Affiliation(s)
- C M Watson
- Embryology Unit, Children's Medical Research Institute, Wentworthville, New South Wales, Australia.
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16
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Abstract
The production of recombinant proteins is one of the major successes of biotechnology. Animal cells are required to synthesize proteins with the appropriate post-translational modifications. Transgenic animals are being used for this purpose. Milk, egg white, blood, urine, seminal plasma and silk worm cocoon from transgenic animals are candidates to be the source of recombinant proteins at an industrial scale. Although the first recombinant protein produced by transgenic animals is expected to be in the market in 2000, a certain number of technical problems remain to be solved before the various systems are optimized. Although the generation of transgenic farm animals has become recently easier mainly with the technique of animal cloning using transfected somatic cells as nuclear donor, this point remains a limitation as far as cost is concerned. Numerous experiments carried out for the last 15 years have shown that the expression of the transgene is predictable only to a limited extent. This is clearly due to the fact that the expression vectors are not constructed in an appropriate manner. This undoubtedly comes from the fact that all the signals contained in genes have not yet been identified. Gene constructions thus result sometime in poorly functional expression vectors. One possibility consists in using long genomic DNA fragments contained in YAC or BAC vectors. The other relies on the identification of the major important elements required to obtain a satisfactory transgene expression. These elements include essentially gene insulators, chromatin openers, matrix attached regions, enhancers and introns. A certain number of proteins having complex structures (formed by several subunits, being glycosylated, cleaved, carboxylated...) have been obtained at levels sufficient for an industrial exploitation. In other cases, the mammary cellular machinery seems insufficient to promote all the post-translational modifications. The addition of genes coding for enzymes involved in protein maturation has been envisaged and successfully performed in one case. Furin gene expressed specifically in the mammary gland proved to able to cleave native human protein C with good efficiency. In a certain number of cases, the recombinant proteins produced in milk have deleterious effects on the mammary gland function or in the animals themselves. This comes independently from ectopic expression of the transgenes and from the transfer of the recombinant proteins from milk to blood. One possibility to eliminate or reduce these side-effects may be to use systems inducible by an exogenous molecule such as tetracycline allowing the transgene to be expressed only during lactation and strictly in the mammary gland. The purification of recombinant proteins from milk is generally not particularly difficult. This may not be the case, however, when the endogenous proteins such as serum albumin or antibodies are abundantly present in milk. This problem may be still more crucial if proteins are produced in blood. Among the biological contaminants potentially present in the recombinant proteins prepared from transgenic animals, prions are certainly those raising the major concern. The selection of animals chosen to generate transgenics on one hand and the elimination of the potentially contaminated animals, thanks to recently defined quite sensitive tests may reduce the risk to an extremely low level. The available techniques to produce pharmaceutical proteins in milk can be used as well to optimize milk composition of farm animals, to add nutriceuticals in milk and potentially to reduce or even eliminate some mammary infectious diseases.
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Affiliation(s)
- L M Houdebine
- Unite de Biologie du Développement et Biotechnologie, Institut National de la Recherche Agronomique, Jouy-en-Josas, France.
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