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Sample records for germ cells pgcs

  1. X-irradiation removes endogenous primordial germ cells (PGCs) and increases germline transmission of donor PGCs in chimeric chickens.

    PubMed

    Nakamura, Yoshiaki; Usui, Fumitake; Miyahara, Daichi; Mori, Takafumi; Ono, Tamao; Kagami, Hiroshi; Takeda, Kumiko; Nirasawa, Keijiro; Tagami, Takahiro

    2012-01-01

    Primordial germ cells (PGCs) are embryonic precursors of germline cells with potential applications in genetic conservation, transgenic animal production and germline stem cell research. These lines of research would benefit from improved germline transmission of transplanted PGCs in chimeric chickens. We therefore evaluated the effects of pretransplant X-irradiation of recipient embryos on the efficacy of germline transmission of donor PGCs in chimeric chickens. Intact chicken eggs were exposed to X-ray doses of 3, 6 and 9 Gy (dose rate = 0.12 Gy/min) after 52 h of incubation. There was no significant difference in hatching rate between the 3-Gy-irradiated group and the nonirradiated control group (40.0 vs. 69.6%), but the hatching rate in the 6-Gy-irradiated group (28.6%) was significantly lower than in the control group (P<0.05). No embryos irradiated with 9 Gy of X-rays survived to hatching. X-irradiation significantly reduced the number of endogenous PGCs in the embryonic gonads at stage 27 in a dose-dependent manner compared with nonirradiated controls. The numbers of endogenous PGCs in the 3-, 6- and 9-Gy-irradiated groups were 21.0, 9.6 and 4.6% of the nonirradiated control numbers, respectively. Sets of 100 donor PGCs were subsequently transferred intravascularly into embryos irradiated with 3 Gy X-rays and nonirradiated control embryos. Genetic cross-test analysis revealed that the germline transmission rate in the 3-Gy-irradiated group was significantly higher than in the control group (27.5 vs. 5.6%; P<0.05). In conclusion, X-irradiation reduced the number of endogenous PGCs and increased the germline transmission of transferred PGCs in chimeric chickens.

  2. Differentiation of presumptive primordial germ cell (pPGC)-like cells in explants into PGCs in experimental tadpoles

    SciTech Connect

    Ikenishi, K.; Okuda, T.; Nakazato, S.

    1984-05-01

    A single blastomere containing the ''germ plasm'' of 32-cell stage Xenopus embryos was cultured with (/sup 3/H)thymidine until the control embryos developed to the neurula stage. The explants, showing a spherical mass in which the nuclei of all cells were labeled, were implanted into the prospective place of presumptive primordial germ cells (pPGCs) in the endodermal cell mass of unlabeled host embryos of the neurula stage. Labeled PGCs as well as unlabeled, host PGCs were found in the genital ridges of experimental tadpoles. This indicates that the precursor of germ cells, corresponding to pPGCs in normal embryos of the neurula stage, in the explants migrated to genital ridges just at the right moment to become PGCs, and suggests that the developmental process progressed normally, even in the explants, as far as the differentiation of pPGCs is concerned.

  3. Effect of microgravity on primordial germ cells (PGCs) in silk chicken offspring ( Gallus gallus domesticus)

    NASA Astrophysics Data System (ADS)

    Zhou, Zhenming; Li, Zandong

    2011-08-01

    Primordial germ cells (PGCs), precursors of germline cells, display a variety of antigens during their migration to target gonads. Here, we used silk chicken offspring ( Gallus gallus domesticus) embryos subjected to space microgravity to investigate the influence of microgravity on PGCs. The ShenZhou-3 unmanned spaceship carried nine fertilized silk chicken eggs, named the flight group, returned to Earth after 7 days space flight. And the control group has the same clan with the flight group. PGCs from flight and control group silk chicken offspring embryos were examined during migration by using two antibodies (2C9 and anti-SSEA-1), in combination with the horseradish peroxidase detection system, and using periodic acid-Schiff's solution (PAS) reaction. After incubation for about 30 h, SSEA-1 and 2C9 positive cells were detected in the germinal crescent of flight and control group silk chicken offspring embryos. After incubation of eggs for 2-2.5 days, SSEA-1 and 2C9 positive cells were detected in embryonic blood vessels of flight and control group silk chicken offspring embryos. After incubation of eggs for 5.5 days, PGCs in the dorsal mesentery and gonad could also be identified in flight and control group silk chicken offspring embryos by using SSEA-1 and 2C9 antibodies. Based on location and PAS staining, these cells were identified as PGCs. Meanwhile, at the stage of PGCs migration and then becoming established in the germinal ridges, no difference in SSEA-1 or 2C9 staining was detected between female and male PGCs in flight and control group silk chicken offspring embryos. Although there were differences in the profiles of PGC concentration between male and female embryos during the special circulating stage, changing profile of PGCs concentration was similar in same sex between flight and control group offspring embryos. We concluded that there is little effect on PGCs in offspring embryos of microgravity-treated chicken and that PGC development appears

  4. Conversion of primordial germ cells to pluripotent stem cells: methods for cell tracking and culture conditions.

    PubMed

    Nagamatsu, Go; Suda, Toshio

    2013-01-01

    Primordial germ cells (PGCs) are unipotent cells committed to germ lineage: PGCs can only differentiate into gametes in vivo. However, upon fertilization, germ cells acquire the capacity to differentiate into all cell types in the body, including germ cells. Therefore, germ cells are thought to have the potential for pluripotency. PGCs can convert to pluripotent stem cells in vitro when cultured under specific conditions that include bFGF, LIF, and the membrane-bound form of SCF (mSCF). Here, the culture conditions which efficiently convert PGCs to pluripotent embryonic germ (EG) cells are described, as well as methods used for identifying pluripotent candidate cells during culture.

  5. Reprogramming of germ cells into pluripotency

    PubMed Central

    Sekita, Yoichi; Nakamura, Toshinobu; Kimura, Tohru

    2016-01-01

    Primordial germ cells (PGCs) are precursors of all gametes, and represent the founder cells of the germline. Although developmental potency is restricted to germ-lineage cells, PGCs can be reprogrammed into a pluripotent state. Specifically, PGCs give rise to germ cell tumors, such as testicular teratomas, in vivo, and to pluripotent stem cells known as embryonic germ cells in vitro. In this review, we highlight the current knowledge on signaling pathways, transcriptional controls, and post-transcriptional controls that govern germ cell differentiation and de-differentiation. These regulatory processes are common in the reprogramming of germ cells and somatic cells, and play a role in the pathogenesis of human germ cell tumors. PMID:27621759

  6. Production of fertile zebrafish (Danio rerio) possessing germ cells (gametes) originated from primordial germ cells recovered from vitrified embryos.

    PubMed

    Higaki, Shogo; Eto, Yoshiki; Kawakami, Yutaka; Yamaha, Etsuro; Kagawa, Noriko; Kuwayama, Masashige; Nagano, Masashi; Katagiri, Seiji; Takahashi, Yoshiyuki

    2010-04-01

    This study aimed to produce fertile zebrafish (Danio rerio) possessing germ cells (gametes) that originated from cryopreserved primordial germ cells (PGCs). First, to improve the vitrification procedure of PGCs in segmentation stage embryos, dechorionated yolk-intact and yolk-removed embryos, the PGCs of which were labeled with green fluorescent protein, were cooled rapidly after serial exposures to equilibration solution (ES) and vitrification solution (VS), which contained ethylene glycol, DMSO, and sucrose. Yolk removal well prevented ice formation in the embryos during cooling and improved the viability of cryopreserved PGCs. The maximum recovery rate of live PGCs in the yolk-removed embryos vitrified after optimum exposure to ES and VS was estimated to be about 90%, and about 50% of the live PGCs showed pseudopodial movement. Next, to elucidate the ability of cryopreserved PGCs to differentiate into functional gametes, PGCs recovered from the yolk-removed embryos (striped-type) that were vitrified under the optimum exposure to ES and VS were transplanted individually into 218 sterilized recipient blastulae (golden-type). Two days after the transplantation, 7.5% (14/187) of morphologically normal embryos had PGC(s) in the genital ridges. Six (5 males and 1 female) of the 14 recipient embryos developed into mature fish and generated progeny with characteristics inherited from PGC donors. In conclusion, we demonstrated the successful cryopreservation of PGCs by vitrification of yolk-removed embryos and the production of fertile zebrafish possessing germ cells that originated from the PGCs in vitrified embryos.

  7. Development, differentiation and manipulation of chicken germ cells.

    PubMed

    Nakamura, Yoshiaki; Kagami, Hiroshi; Tagami, Takahiro

    2013-01-01

    Germ cells are the only cell type capable of transmitting genetic information to the next generation. During development, they are set aside from all somatic cells of the embryo. In many species, germ cells form at the fringe of the embryo proper and then traverse through several developing somatic tissues on their migration to the emerging gonads. Primordial germ cells (PGCs) are the only cells in developing embryos with the potential to transmit genetic information to the next generation. Unlike other species, in avian embryos, PGCs use blood circulation for transport to the future gonadal region. This unique accessibility of avian PGCs during early development provides an opportunity to collect and transplant PGCs. The recent development of methods for production of germline chimeras by transfer of PGCs, and long-term cultivation methods of chicken PGCs without losing their germline transmission ability have provided important breakthroughs for the preservation of germplasm , for the production of transgenic birds and study the germ cell system. This review will describe the development, migration, differentiation and manipulation of germ cells, and discuss the prospects that germ cell technologies offer for agriculture, biotechnology and academic research. © 2013 The Authors Development, Growth & Differentiation © 2013 Japanese Society of Developmental Biologists.

  8. MASTL is essential for anaphase entry of proliferating primordial germ cells and establishment of female germ cells in mice

    PubMed Central

    Risal, Sanjiv; Zhang, Jingjing; Adhikari, Deepak; Liu, Xiaoman; Shao, Jingchen; Hu, Mengwen; Busayavalasa, Kiran; Tu, Zhaowei; Chen, Zijiang; Kaldis, Philipp; Liu, Kui

    2017-01-01

    In mammals, primordial germ cells (PGCs) are the embryonic cell population that serve as germ cell precursors in both females and males. During mouse embryonic development, the majority of PGCs are arrested at the G2 phase when they migrate into the hindgut at 7.75–8.75 dpc (days post coitum). It is after 9.5 dpc that the PGCs undergo proliferation with a doubling time of 12.6 h. The molecular mechanisms underlying PGC proliferation are however not well studied. In this work. Here we studied how MASTL (microtubule-associated serine/threonine kinase-like)/Greatwall kinase regulates the rapid proliferation of PGCs. We generated a mouse model where we specifically deleted Mastl in PGCs and found a significant loss of PGCs before the onset of meiosis in female PGCs. We further revealed that the deletion of Mastl in PGCs did not prevent mitotic entry, but led to a failure of the cells to proceed beyond metaphase-like stage, indicating that MASTL-mediated molecular events are indispensable for anaphase entry in PGCs. These mitotic defects further led to the death of Mastl-null PGCs by 12.5 dpc. Moreover, the defect in mitotic progression observed in the Mastl-null PGCs was rescued by simultaneous deletion of Ppp2r1a (α subunit of PP2A). Thus, our results demonstrate that MASTL, PP2A, and therefore regulated phosphatase activity have a fundamental role in establishing female germ cell population in gonads by controlling PGC proliferation during embryogenesis. PMID:28224044

  9. Transient translational quiescence in primordial germ cells.

    PubMed

    Oulhen, Nathalie; Swartz, S Zachary; Laird, Jessica; Mascaro, Alexandra; Wessel, Gary

    2017-02-24

    Stem cells in animals often exhibit a slow cell cycle and/or low transcriptional activity referred to as quiescence. Here we report that the translational activity in the primordial germ cells (PGCs) of the sea urchin embryo (Strongylocentrotus purpuratus) is quiescent. We measured new protein synthesis with O-propargyl-puromycin, and L-homopropargylglycine, Click-iT technologies and determined that these cells synthesize protein at only 6% the level of their adjacent somatic cells. Knock-down of translation of the RNA-binding protein Nanos2 by morpholino anti-sense oligonucleotides, or knock-out of the Nanos2 gene by CRISPR/Cas9 resulted in a significant, but partial increase (47%) in general translation specifically in the PGCs. We found that the mRNA of the translation factor eEF1A is excluded from the PGCs in a Nanos2-dependent manner, a consequence of a Nanos/Pumilio response element (PRE) in its 3'UTR. In addition to eEF1A, the cytoplasmic pH of the PGCs appears to repress translation and simply increasing the pH also significantly restores translation selectively in the PGCs. We conclude that the PGCs of this sea urchin institute parallel pathways to quiesce translation thoroughly but transiently.

  10. Cholesterol induces proliferation of chicken primordial germ cells.

    PubMed

    Chen, Dongyang; Chen, Meijuan; Lu, Zhenping; Yang, Mengmeng; Xie, Long; Zhang, Wenxin; Xu, Huiyan; Lu, Kehuan; Lu, Yangqing

    2016-08-01

    Primordial germ cells (PGCs) are the precursors of sperm and eggs and may serve as suitable cells for use in research in developmental biology and transgenic animals. However, the long-term propagation of PGCs in vitro has so far been plagued by the loss of their germ cell characteristics. This is largely because of the scarcity of knowledge concerning cell division and proliferation in these cells and the poor optimization of the culture medium. The sonic hedgehog (SHH) signaling pathway is involved in proliferation of many types of cells, but little is known about its role in chicken PGCs. The results of the current study indicate that the proliferation of chicken PGCs increases significantly when cholesterol, a molecule that facilitates the trafficking of HH ligands, is supplemented in the culture medium. This effect was attenuated when an SHH antagonist, cyclopamine was added, suggesting the involvement of SHH signaling in this process. The characterization of PGCs treated with cholesterol has shown that these cells express germ-cell-related markers and retain their capability to colonize the embryonic gonad after re-introduction to vasculature of stage-15 HH embryos, indicating that proliferation of PGCs induced by cholesterol does not alter the germ cell characteristics of these cells.

  11. Xenopus Vasa Homolog XVLG1 is Essential for Migration and Survival of Primordial Germ Cells.

    PubMed

    Shimaoka, Kazumi; Mukumoto, Yoshiko; Tanigawa, Yoko; Komiya, Tohru

    2017-04-01

    Xenopus vasa-like gene 1 (XVLG1), a DEAD-Box Helicase 4 (DDX4) gene identified as a vertebrate vasa homologue, is required for the formation of primordial germ cells (PGCs). However, it remains to be clarified when and how XVLG1 functions in the formation of the germ cells. To gain a better understanding of the molecular mechanisms underlying XVLG1 during PGC development, we injected XVLG1 morpholino oligos into germ-plasm containing blastomeres of 32-cell stage of Xenopus embryos, and traced cell fates of the injected blastomere-derived PGCs. As a result of this procedure, migration of the PGCs was impaired and the number of PGCs derived from the blastomeres was significantly decreased. In addition, TUNEL staining in combination with in situ hybridization revealed that the loss of PGCs peaked at stage 27 was caused by apoptosis. This data strongly suggests an essential role for XVLG1 in migration and survival of the germ cells.

  12. Specification of primordial germ cells in medaka (Oryzias latipes)

    PubMed Central

    Herpin, Amaury; Rohr, Stefan; Riedel, Dietmar; Kluever, Nils; Raz, Erez; Schartl, Manfred

    2007-01-01

    Background Primordial germ cells (PGCs) give rise to gametes that are responsible for the development of a new organism in the next generation. Two modes of germ line specification have been described: the inheritance of asymmetrically-localized maternally provided cytoplasmic determinants and the induction of the PGC fate by other cell types. PGCs specification in zebrafish appears to depend on inheritance of germ plasm in which several RNA molecules such as vasa and nanos reside. Whether the specification mode of PGCs found in zebrafish is general for other fish species was brought into question upon analysis of olvas expression – the vasa homologue in another teleost, medaka (Oryzias latipes). Here, in contrast to the findings in zebrafish, the PGCs are found in a predictable position relative to a somatic structure, the embryonic shield. This finding, coupled with the fact that vasa mRNA, which is localized to the germ plasm of zebrafish but does not label a similar structure in medaka opened the possibility of fundamentally different mechanisms governing PGC specification in these two fish species. Results In this study we addressed the question concerning the mode of PGC specification in medaka using embryological experiments, analysis of RNA stability in the PGCs and electron microscopy observations. Dramatic alterations in the somatic environment, i.e. induction of a secondary axis or mesoderm formation alteration, did not affect the PGC number. Furthermore, the PGCs of medaka are capable of protecting specific RNA molecules from degradation and could therefore exhibit a specific mRNA expression pattern controlled by posttrancriptional mechanisms. Subsequent analysis of 4-cell stage medaka embryos using electron microscopy revealed germ plasm-like structures located at a region corresponding to that of zebrafish germ plasm. Conclusion Taken together, these results are consistent with the idea that in medaka the inheritance of maternally provided

  13. Specification of germ cell fate in mice.

    PubMed Central

    Saitou, Mitinori; Payer, Bernhard; Lange, Ulrike C; Erhardt, Sylvia; Barton, Sheila C; Surani, M Azim

    2003-01-01

    An early fundamental event during development is the segregation of germ cells from somatic cells. In many organisms, this is accomplished by the inheritance of preformed germ plasm, which apparently imposes transcriptional repression to prevent somatic cell fate. However, in mammals, pluripotent epiblast cells acquire germ cell fate in response to signalling molecules. We have used single cell analysis to study how epiblast cells acquire germ cell competence and undergo specification. Germ cell competent cells express Fragilis and initially progress towards a somatic mesodermal fate. However, a subset of these cells, the future primordial germ cells (PGCs), then shows rapid upregulation of Fragilis with concomitant transcriptional repression of a number of genes, including Hox and Smad genes. This repression may be a key event associated with germ cell specification. Furthermore, PGCs express Stella and other genes, such as Oct-4 that are associated with pluripotency. While these molecules are also detected in mature oocytes as maternally inherited factors, their early role is to regulate development and maintain pluripotency, and they do not serve the role of classical germline determinants. PMID:14511483

  14. Improvement of transfection efficiency in cultured chicken primordial germ cells by percoll density gradient centrifugation.

    PubMed

    Oishi, Isao

    2010-01-01

    Chicken primordial germ cells (PGCs) differentiate into germ cells in gonads. Because PGCs can be cloned and cultured maintaining germline competency, they are a good means of modifying the chicken genome, but the efficiency of plasmid transfection into PGCs is very low. In this study, I attempted to improve the efficiency of PGC transfection. Cultured PGCs were purified by Percoll density gradient centrifugation, and were then transfected with plasmid DNA. For transient transfection, the transfection efficiency increased more than 7-fold by the Percoll method. The efficiency of stable transfection of PGCs also increased significantly. The stable transfectants that were isolated by this method accumulated in the developing gonads after microinjection into bloodstream of chick embryos, indicating that gene transfection by Percoll purification did not alter the function of PGCs in vivo.

  15. The majority of early primordial germ cells acquire pluripotency by AKT activation.

    PubMed

    Matsui, Yasuhisa; Takehara, Asuka; Tokitake, Yuko; Ikeda, Makiko; Obara, Yuka; Morita-Fujimura, Yuiko; Kimura, Tohru; Nakano, Toru

    2014-12-01

    Primordial germ cells (PGCs) are undifferentiated germ cells in embryos, the fate of which is to become gametes; however, mouse PGCs can easily be reprogrammed into pluripotent embryonic germ cells (EGCs) in culture in the presence of particular extracellular factors, such as combinations of Steel factor (KITL), LIF and bFGF (FGF2). Early PGCs form EGCs more readily than do later PGCs, and PGCs lose the ability to form EGCs by embryonic day (E) 15.5. Here, we examined the effects of activation of the serine/threonine kinase AKT in PGCs during EGC formation; notably, AKT activation, in combination with LIF and bFGF, enhanced EGC formation and caused ∼60% of E10.5 PGCs to become EGCs. The results indicate that the majority of PGCs at E10.5 could acquire pluripotency with an activated AKT signaling pathway. Importantly, AKT activation did not fully substitute for bFGF and LIF, and AKT activation without both LIF and bFGF did not result in EGC formation. These findings indicate that AKT signal enhances and/or collaborates with signaling pathways of bFGF and of LIF in PGCs for the acquisition of pluripotency. © 2014. Published by The Company of Biologists Ltd.

  16. Migration and proliferation of intact and genetically modified primordial germ cells and the generation of a transgenic chicken.

    PubMed

    Kim, Jin Nam; Park, Tae Sub; Park, Sang Hyun; Park, Kyung Je; Kim, Tae Min; Lee, Seul Ki; Lim, Jeong Mook; Han, Jae Yong

    2010-02-01

    This study evaluated gonadal migration and postmigratory proliferation of intact and genetically modified chicken primordial germ cells (PGCs). A randomized, controlled trial was conducted with the gonadal population of PGCs and transgenic chicken production as major parameters. PGCs (0, 90, 900, 1800, or 3000 cells) were transferred into 53-h-old embryos. The percentage of PGCs migrating on Day 6 of development was highest (35.8%) following the transfer of 900 PGCs and did not change with increases in transferred PGCs. The number of migrating PGCs gradually increased (P = 0.0001) as the number of transferred PGCs was increased. Gonadal migration was detected after the transfer of intact and genetically modified PGCs, but prominent decreases in PGC migration (from 21.9% to 0.38%) and chimera ratio (from 0.4 to 0.007) occurred with genetically modified PGCs. However, subsequent vigorous proliferation of the modified PGCs (3.67-fold increase from transferred number) led to the derivation of a germline chimera and produced a transgenic hatchling. In conclusion, the number of migrating PGCs increased as the number of transferred cells increased. Vigorous proliferation after transfer compensated for the decreased migration capacity of genetically modified PGCs and resulted in the production of a transgenic chicken.

  17. Spatial and temporal action of chicken primordial germ cells during initial migration.

    PubMed

    Kang, Kyung Soo; Lee, Hyung Chul; Kim, Hyun Jeong; Lee, Hyo Gun; Kim, Young Min; Lee, Hong Jo; Park, Young Hyun; Yang, Seo Yeong; Rengaraj, Deivendran; Park, Tae Sub; Han, Jae Yong

    2015-02-01

    In most animals, primordial germ cells (PGCs) originate from an extragonadal region and migrate across the embryo to the gonads, where they differentiate and function. During their migration, PGCs move passively by morphogenetic movement of the embryo or move actively through signaling molecules. To uncover the underlying mechanism of first-phase PGC migration toward the germinal crescent in chickens, we investigated the spatial and temporal action of PGCs during primitive streak formation. Exogenously transplanted PGCs migrated toward the anterior region of the embryo and the embryonic gonads when they were transplanted into the subgerminal cavity, but not into the posterior marginal zone, in Eyal-Giladi and Kochav stage X embryos. These results indicate that for passive migration toward the anterior region the initial location of PGCs should be the central region. Notably, although PGCs and DF-1 cells migrated passively toward the anterior region, only PGCs migrated to the germinal crescent, where endogenous PGCs mainly reside, by active movement. In a live-imaging experiment with green fluorescence protein-expressing transgenic embryos, exogenous PGCs demonstrated markedly faster migration when they reached the anterior one-third of the embryo, while somatic cells showed epiblast movement with constant speed. Also, migrating PGCs exhibited successive contraction and expansion indicating their active migration. Our results suggest that chicken PGCs use sequential passive and active forces to migrate toward the germinal crescent.

  18. Detection and characterization of primordial germ cells in pheasant (Phasianus colchicus) embryos.

    PubMed

    Kim, Jin Nam; Lee, Young Mok; Park, Tae Sub; Jung, Jin Gyoung; Cho, Byeong Wook; Lim, Jeong Mook; Han, Jae Yong

    2005-03-01

    The developmental similarity between the chicken and pheasant (Phasianus colchicus) allows the novel biotechnologies developed in the chicken to be applied to the production of transgenic pheasants and interspecies germline chimeras. To detect pheasant primordial germ cells (PGCs) efficiently, which is important for inducing germline transmission, the ultrastructure of PGCs and their reactivity to several antibodies (2C9, QB2, anti-SSEA-1, and QCR1) and periodic acid-Schiff's solution (PAS) were examined. To obtain PGCs, blood was taken from embryos incubated for 62-72 h or from gonads from embryos incubated for 156-216 h. The PGCs collected from both sources had the typical ultrastructure of pluripotent cells: a large nucleus with a distinct nucleolus, a high ratio of nuclear to cytoplasmic volume, and a distinct cytoplasmic membrane. In comparing the morphology of PGCs collected from different sites, more mitochondria and better-developed membrane microvilli were found in gonadal PGCs than in circulating PGCs. The nucleus of gonadal PGCs was flattened and had a large eccentrically positioned nucleolus. Of the antibodies tested, only QCR1 antibody reacted with an epitope in pheasant PGCs, and no specific signal was detected to other antibodies. The temporal change in the PGC populations in the blood and gonads of embryos was examined. In blood, the population was greater (P < 0.0001) in embryos incubated for 64 h than in embryos incubated for 62 or 66-72 h (31.4 versus 5.6-16.2 microL(-1)). In embryonic gonads, the number of PGCs increased continuously from 156 to 216 h of incubation (193-2,718 cells/embryo), although the ratio of PGCs to total gonadal cells did not change significantly (0.50-0.61%). In conclusion, pheasant PGCs have typical germ cell morphology and possess the QCR1 epitope. Circulating blood and the gonads of embryos incubated for 64 and 216 h, respectively, are good sources of PGCs.

  19. Germ cell regeneration-mediated, enhanced mutagenesis in the ascidian Ciona intestinalis reveals flexible germ cell formation from different somatic cells.

    PubMed

    Yoshida, Keita; Hozumi, Akiko; Treen, Nicholas; Sakuma, Tetsushi; Yamamoto, Takashi; Shirae-Kurabayashi, Maki; Sasakura, Yasunori

    2017-03-15

    The ascidian Ciona intestinalis has a high regeneration capacity that enables the regeneration of artificially removed primordial germ cells (PGCs) from somatic cells. We utilized PGC regeneration to establish efficient methods of germ line mutagenesis with transcription activator-like effector nucleases (TALENs). When PGCs were artificially removed from animals in which a TALEN pair was expressed, somatic cells harboring mutations in the target gene were converted into germ cells, this germ cell population exhibited higher mutation rates than animals not subjected to PGC removal. PGC regeneration enables us to use TALEN expression vectors of specific somatic tissues for germ cell mutagenesis. Unexpectedly, cis elements for epidermis, neural tissue and muscle could be used for germ cell mutagenesis, indicating there are multiple sources of regenerated PGCs, suggesting a flexibility of differentiated Ciona somatic cells to regain totipotency. Sperm and eggs of a single hermaphroditic, PGC regenerated animal typically have different mutations, suggesting they arise from different cells. PGCs can be generated from somatic cells even though the maternal PGCs are not removed, suggesting that the PGC regeneration is not solely an artificial event but could have an endogenous function in Ciona. This study provides a technical innovation in the genome-editing methods, including easy establishment of mutant lines. Moreover, this study suggests cellular mechanisms and the potential evolutionary significance of PGC regeneration in Ciona.

  20. Rebuilding pluripotency from primordial germ cells.

    PubMed

    Leitch, Harry G; Nichols, Jennifer; Humphreys, Peter; Mulas, Carla; Martello, Graziano; Lee, Caroline; Jones, Ken; Surani, M Azim; Smith, Austin

    2013-01-01

    Mammalian primordial germ cells (PGCs) are unipotent progenitors of the gametes. Nonetheless, they can give rise directly to pluripotent stem cells in vitro or during teratocarcinogenesis. This conversion is inconsistent, however, and has been difficult to study. Here, we delineate requirements for efficient resetting of pluripotency in culture. We demonstrate that in defined conditions, routinely 20% of PGCs become EG cells. Conversion can occur from the earliest specified PGCs. The entire process can be tracked from single cells. It is driven by leukemia inhibitory factor (LIF) and the downstream transcription factor STAT3. In contrast, LIF signaling is not required during germ cell ontogeny. We surmise that ectopic LIF/STAT3 stimulation reconstructs latent pluripotency and self-renewal. Notably, STAT3 targets are significantly upregulated in germ cell tumors, suggesting that dysregulation of this pathway may underlie teratocarcinogenesis. These findings demonstrate that EG cell formation is a robust experimental system for exploring mechanisms involved in reprogramming and cancer.

  1. Male Differentiation of Germ Cells Induced by Embryonic Age-Specific Sertoli Cells in Mice1

    PubMed Central

    Ohta, Kohei; Yamamoto, Miyuki; Lin, Yanling; Hogg, Nathanael; Akiyama, Haruhiko; Behringer, Richard R.; Yamazaki, Yukiko

    2012-01-01

    ABSTRACT Retinoic acid (RA) is a meiosis-inducing factor. Primordial germ cells (PGCs) in the developing ovary are exposed to RA, resulting in entry into meiosis. In contrast, PGCs in the developing testis enter mitotic arrest to differentiate into prospermatogonia. Sertoli cells express CYP26B1, an RA-metabolizing enzyme, providing a simple explanation for why XY PGCs do not initiate meios/is. However, regulation of entry into mitotic arrest is likely more complex. To investigate the mechanisms that regulate male germ cell differentiation, we cultured XX and XY germ cells at 11.5 and 12.5 days postcoitus (dpc) with an RA receptor inhibitor. Expression of Stra8, a meiosis initiation gene, was suppressed in all groups. However, expression of Dnmt3l, a male-specific gene, during embryogenesis was elevated but only in 12.5-dpc XY germ cells. This suggests that inhibiting RA signaling is not sufficient for male germ cell differentiation but that the male gonadal environment also contributes to this pathway. To define the influence of Sertoli cells on male germ cell differentiation, Sertoli cells at 12.5, 15.5, and 18.5 dpc were aggregated with 11.5 dpc PGCs, respectively. After culture, PGCs aggregated with 12.5 dpc Sertoli cells increased Nanos2 and Dnmt3l expression. Furthermore, these PGCs established male-specific methylation imprints of the H19 differentially methylated domains. In contrast, PGCs aggregated with Sertoli cells at late embryonic ages did not commit to the male pathway. These findings suggest that male germ cell differentiation is induced both by inhibition of RA signaling and by molecule(s) production by embryonic age-specific Sertoli cells. PMID:22262692

  2. Formation and cultivation of medaka primordial germ cells.

    PubMed

    Li, Zhendong; Li, Mingyou; Hong, Ni; Yi, Meisheng; Hong, Yunhan

    2014-07-01

    Primordial germ cell (PGC) formation is pivotal for fertility. Mammalian PGCs are epigenetically induced without the need for maternal factors and can also be derived in culture from pluripotent stem cells. In egg-laying animals such as Drosophila and zebrafish, PGCs are specified by maternal germ plasm factors without the need for inducing factors. In these organisms, PGC formation and cultivation in vitro from indeterminate embryonic cells have not been possible. Here, we report PGC formation and cultivation in vitro from blastomeres dissociated from midblastula embryos (MBEs) of the fish medaka (Oryzias latipes). PGCs were identified by using germ-cell-specific green fluorescent protein (GFP) expression from a transgene under the control of the vasa promoter. Embryo perturbation was exploited to study PGC formation in vivo, and dissociated MBE cells were cultivated under various conditions to study PGC formation in vitro. Perturbation of somatic development did not prevent PGC formation in live embryos. Dissociated MBE blastomeres formed PGCs in the absence of normal somatic structures and of known inducing factors. Most importantly, under culture conditions conducive to stem cell derivation, some dissociated MBE blastomeres produced GFP-positive PGC-like cells. These GFP-positive cells contained genuine PGCs, as they expressed PGC markers and migrated into the embryonic gonad to generate germline chimeras. Our data thus provide evidence for PGC preformation in medaka and demonstrate, for the first time, that PGC formation and derivation can be obtained in culture from early embryos of medaka as a lower vertebrate model.

  3. Nanog regulates primordial germ cell migration through Cxcr4b.

    PubMed

    Sánchez-Sánchez, Ana Virginia; Camp, Esther; Leal-Tassias, Aránzazu; Atkinson, Stuart P; Armstrong, Lyle; Díaz-Llopis, Manuel; Mullor, José L

    2010-09-01

    Gonadal development in vertebrates depends on the early determination of primordial germ cells (PGCs) and their correct migration to the sites where the gonads develop. Several genes have been implicated in PGC specification and migration in vertebrates. Additionally, some of the genes associated with pluripotency, such as Oct4 and Nanog, are expressed in PGCs and gonads, suggesting a role for these genes in maintaining pluripotency of the germ lineage, which may be considered the only cell type that perpetually maintains stemness properties. Here, we report that medaka Nanog (Ol-Nanog) is expressed in the developing PGCs. Depletion of Ol-Nanog protein causes aberrant migration of PGCs and inhibits expression of Cxcr4b in PGCs, where it normally serves as the receptor of Sdf1a to guide PGC migration. Moreover, chromatin immunoprecipitation analysis demonstrates that Ol-Nanog protein binds to the promoter region of Cxcr4b, suggesting a direct regulation of Cxcr4b by Ol-Nanog. Simultaneous overexpression of Cxcr4b mRNA and depletion of Ol-Nanog protein in PGCs rescues the migration defective phenotype induced by a loss of Ol-Nanog, whereas overexpression of Sdf1a, the ligand for Cxcr4b, does not restore proper PGC migration. These results indicate that Ol-Nanog mediates PGC migration by regulating Cxcr4b expression.

  4. Specifying and protecting germ cell fate

    PubMed Central

    Strome, Susan; Updike, Dustin

    2015-01-01

    Germ cells are the special cells in the body that undergo meiosis to generate gametes and subsequently entire new organisms after fertilization, a process that continues generation after generation. Recent studies have expanded our understanding of the factors and mechanisms that specify germ cell fate, including the partitioning of maternally supplied ‘germ plasm’, inheritance of epigenetic memory and expression of transcription factors crucial for primordial germ cell (PGC) development. Even after PGCs are specified, germline fate is labile and thus requires protective mechanisms, such as global transcriptional repression, chromatin state alteration and translation of only germline-appropriate transcripts. Findings from diverse species continue to provide insights into the shared and divergent needs of these special reproductive cells. PMID:26122616

  5. Generation of germ-line chimera zebrafish using primordial germ cells isolated from cultured blastomeres and cryopreserved embryoids.

    PubMed

    Kawakami, Yutaka; Goto-Kazeto, Rie; Saito, Taiju; Fujimoto, Takafumi; Higaki, Shogo; Takahashi, Yoshiyuki; Arai, Katsutoshi; Yamaha, Etsuro

    2010-01-01

    Primordial germ cells (PGCs) are the only cells in developing embryos with the potential to transmit genetic information to the next generation. In our previous study, a single PGC transplanted into a host differentiated into fertile gametes and produced germ-line chimeras of cyprinid fish, including zebrafish. In this study, we aimed to induce germ-line chimeras by transplanting donor PGCs from various sources (normal embryos at different stages, dissociated blastomeres, embryoids, or embryoids cryopreserved by vitrification) into host blastulae, and compare the migration rates of the PGCs towards the gonadal ridge. Isolated, cultured blastomeres not subject to mesodermal induction were able to differentiate into PGCs that retained their motility. Moreover, these PGCs successfully migrated towards the gonadal ridge of the host and formed viable gametes. Motility depended on developmental stage and culture duration: PGCs obtained at earlier developmental stages and with shorter cultivation periods showed an increased rate of migration to the gonadal ridge. Offspring were obtained from natural spawning between normal females and chimeric males. These results provide the basis for new methods of gene preservation in zebrafish.

  6. Restricted distribution of mrg-1 mRNA in C. elegans primordial germ cells through germ granule-independent regulation.

    PubMed

    Miwa, Takashi; Takasaki, Teruaki; Inoue, Kunio; Sakamoto, Hiroshi

    2015-11-01

    The chromodomain protein MRG-1 is an essential maternal factor for proper germline development that protects germ cells from cell death in C. elegans. Unlike germ granules, which are exclusively segregated to the germline blastomeres at each cell division from the first cleavage of the embryo, MRG-1 is abundant in all cells in early embryos and is then gradually restricted to the primordial germ cells (PGCs) by the morphogenesis stage. Here, we show that this characteristic spatiotemporal expression pattern is dictated by the mrg-1 3'UTR and is differentially regulated at the RNA level between germline and somatic cells. Asymmetric segregation of germ granules is not necessary to localize MRG-1 to the PGCs. We found that MES-4, an essential chromatin regulator in germ cells, also accumulates in the PGCs in a germ granule-independent manner. We propose that C.elegans PGCs have a novel mechanism to accumulate at least some chromatin-associated proteins that are essential for germline immortality. © 2015 The Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

  7. Efficient TALEN-mediated gene targeting of chicken primordial germ cells

    PubMed Central

    Taylor, Lorna; Carlson, Daniel F.; Nandi, Sunil; Sherman, Adrian; Fahrenkrug, Scott C.

    2017-01-01

    In this work we use TALE nucleases (TALENs) to target a reporter construct to the DDX4 (vasa) locus in chicken primordial germ cells (PGCs). Vasa is a key germ cell determinant in many animal species and is posited to control avian germ cell formation. We show that TALENs mediate homology-directed repair of the DDX4 locus on the Z sex chromosome at high (8.1%) efficiencies. Large genetic deletions of 30 kb encompassing the entire DDX4 locus were also created using a single TALEN pair. The targeted PGCs were germline competent and were used to produce DDX4 null offspring. In DDX4 knockout chickens, PGCs are initially formed but are lost during meiosis in the developing ovary, leading to adult female sterility. TALEN-mediated gene targeting in avian PGCs is therefore an efficient process. PMID:28174243

  8. Comparative molecular portraits of human unfertilized oocytes and primordial germ cells at 10 weeks of gestation.

    PubMed

    Diedrichs, Ferdinand; Mlody, Barbara; Matz, Peggy; Fuchs, Heiko; Chavez, Lukas; Drews, Katharina; Adjaye, James

    2012-01-01

    Primordial germ cells (PGCs) are precursors of gametes and share several features in common with pluripotent stem cells, such as alkaline phosphatase activity and the expression of pluripotency-associated genes such as OCT4 and NANOG. PGCs are able to differentiate into oocytes and spermatogonia and establish totipotency after fertilization. However, our knowledge of human germ cell development is still fragmentary. In this study, we have carried out genome-wide comparisons of the transcriptomes and molecular portraits of human male PGCs (mPGCs), female PGCs (fPGCs) and unfertilized oocytes. We detected 9210 genes showing elevated expression in fPGCs, 9184 in mPGCs and 9207 in oocytes, with 6342 of these expressed in common. As well as known germ cell-related genes such as BLIMP1/PRDM1, PIWIL2, VASA/DDX4, DAZL, STELLA/DPPA3 and LIN28, we also identified 465 novel non-annotated genes with orthologs in the mouse. A plethora of olfactory receptor-encoding genes were detected in all samples, which would suggest their involvement not only in sperm chemotaxis, but also in the development of female germ cells and oocytes. We anticipate that our data might increase our meagre knowledge of the genes and associated signaling pathways operative during germ cell development. This in turn might aid in the development of strategies enabling better differentiation and molecular characterisation of germ cells derived from either embryonic or induced pluripotent stem cells. Ultimately, this would have a profound relevance for reproductive as well as regenerative medicine.

  9. Differential Expression of Conserved Germ Line Markers and Delayed Segregation of Male and Female Primordial Germ Cells in a Hermaphrodite, the Leech Helobdella

    PubMed Central

    Cho, Sung-Jin; Vallès, Yvonne; Weisblat, David A.

    2014-01-01

    In sexually reproducing animals, primordial germ cells (PGCs) are often set aside early in embryogenesis, a strategy that minimizes the risk of genomic damage associated with replication and mitosis during the cell cycle. Here, we have used germ line markers (piwi, vasa, and nanos) and microinjected cell lineage tracers to show that PGC specification in the leech genus Helobdella follows a different scenario: in this hermaphrodite, the male and female PGCs segregate from somatic lineages only after more than 20 rounds of zygotic mitosis; the male and female PGCs share the same (mesodermal) cell lineage for 19 rounds of zygotic mitosis. Moreover, while all three markers are expressed in both male and female reproductive tissues of the adult, they are expressed differentially between the male and female PGCs of the developing embryo: piwi and vasa are expressed preferentially in female PGCs at a time when nanos is expressed preferentially in male PGCs. A priori, the delayed segregation of male and female PGCs from somatic tissues and from one another increases the probability of mutations affecting both male and female PGCs of a given individual. We speculate that this suite of features, combined with a capacity for self-fertilization, may contribute to the dramatically rearranged genome of Helobdella robusta relative to other animals. PMID:24217283

  10. Feasibility of cryopreservation of zebrafish (Danio rerio) primordial germ cells by whole embryo freezing.

    PubMed

    Higaki, Shogo; Mochizuki, Kentaro; Baba, Hiroko; Akashi, Yuichiro; Yamaha, Etsuro; Katagiri, Seiji; Takahashi, Yoshiyuki

    2009-08-01

    We investigated the feasibility of cryopreservation of zebrafish (Danio rerio) blastomeres and primordial germ cells (PGCs) by rapid freezing of dechorionated whole embryos at the blastula, gastrula and segmentation stages. Initially we examined the glass-forming properties and embryo toxicities of 5 cryoprotectants: methanol (MeOH), ethylene glycol (EG), dimethyl sulfoxide (DMSO), propylene glycol (PG), and 1,3-butylene glycol (1,3-BG). Embryos at the blastula and gastrula stages had high sensitivities to cryoprotectant toxicities and were fragile against mechanical damage. Thus the segmentation stage embryos, the PGCs of which were visualized by injecting green fluorescence protein-nos1 3'UTR mRNA, were frozen using solutions containing each cryoprotectant at 6 M (first trial) and 2 types of cryoprotectants at 3 M each (second trial). In the first trial, live PGCs were recovered from most of the embryos frozen with EG (about 2 cells/embryo); however, a few embryos had live PGCs when embryos were frozen with other cryoprotectants. In the second trial, a mixture of EG + PG better preserved the viability of PGCs in frozen embryos. Live PGCs were recovered from all embryos frozen with EG + PG (about 3 cells/embryo), and the survival rate of PGCs was estimated to be about 25% based on the number of live PGCs in fresh embryos (about 12 cells/embryo). The present study indicates that we can utilize rapid freezing of dechorionated whole embryos at the segmentation stage for the cryopreservation of PGCs.

  11. BMP4 can generate primordial germ cells from bone-marrow-derived pluripotent stem cells.

    PubMed

    Shirazi, Reza; Zarnani, Amir Hassan; Soleimani, Masoud; Abdolvahabi, Mir Abbas; Nayernia, Karim; Ragerdi Kashani, Iraj

    2012-01-01

    Evidence of germ cell derivation from embryonic and somatic stem cells provides an in vitro model for the study of germ cell development, associated epigenetic modification and mammalian gametogenesis. More importantly, in vitro derived gametes also represent a potential strategy for treating infertility. In mammals, male and female gametes, oocyte and sperm, are derived from a specific cell population, PGCs (primordial germ cells) that segregate early in embryogenesis. We have isolated pluripotent SSEA-1+ (stage-specific embryonic antigen-1+) cells from mice bone marrow using a MACS (magnetic-activated cell sorting) system. SSEA-1+ cells were directly separated from the suspension of MMCs (murine mononuclear cells) harvested from bone marrow of 2-4-week-old mice. Flow-cytometry assay immediately after sorting and culturing under undifferentiated condition showed 55±7% and 87±4% purity respectively. RT-PCR (reverse transcription-PCR) analysis after differentiation of SSEA-1+ cells into derivations of three germ layers showed the pluripotency properties of isolated cells. SSEA-1+ cells were induced to differentiate along germ cell lineage by adding BMP4 (bone morphogenic factor-4) to the medium. Regarding the expression of germ cell markers (PGCs, male and female germ cell lineage), it was found that adding exogenous BMP4 to culture medium could differentiate pluripotent SSEA-1+ cells isolated from an adult tissue into gamete precursors, PGCs. Differentiated cells expressed specific molecular markers of PGCs, including Oct4, fragilis, Stella and Mvh (mouse vasa homologue). Therefore BMP4 is insufficient to induce SSEA-1+ cells derived from PGCs to develop further into late germ cells in vitro.

  12. Metastable primordial germ cell-like state induced from mouse embryonic stem cells by Akt activation

    SciTech Connect

    Yamano, Noriko; Kimura, Tohru; Watanabe-Kushima, Shoko; Shinohara, Takashi; Nakano, Toru

    2010-02-12

    Specification to primordial germ cells (PGCs) is mediated by mesoderm-induction signals during gastrulation. We found that Akt activation during in vitro mesodermal differentiation of embryonic stem cells (ESCs) generated self-renewing spheres with differentiation states between those of ESCs and PGCs. Essential regulators for PGC specification and their downstream germ cell-specific genes were expressed in the spheres, indicating that the sphere cells had commenced differentiation to the germ lineage. However, the spheres did not proceed to spermatogenesis after transplantation into testes. Sphere cell transfer to the original feeder-free ESC cultures resulted in chaotic differentiation. In contrast, when the spheres were cultured on mouse embryonic fibroblasts or in the presence of ERK-cascade and GSK3 inhibitors, reversion to the ESC-like state was observed. These results indicate that Akt signaling promotes a novel metastable and pluripotent state that is intermediate to those of ESCs and PGCs.

  13. Mechanisms guiding primordial germ cell migration: strategies from different organisms

    PubMed Central

    Richardson, Brian E.; Lehmann, Ruth

    2015-01-01

    Preface The regulated migration of cells is essential for development and tissue homeostasis, and aberrant cell migration can lead to an impaired immune response and the progression of cancer. Primordial germ cells (PGCs), precursors to sperm and eggs, have to migrate across the embryo to reach somatic gonadal precursors (SGPs) and fulfill their function. Studies of model organisms have revealed that, despite important differences, several features of PGC migration are conserved. PGCs require both an intrinsic motility program and external guidance cues to survive and successfully migrate. Proper guidance involves both attractive and repulsive cues mediated by protein and lipid signalling. PMID:20027186

  14. A replication-dependent passive mechanism modulates DNA demethylation in mouse primordial germ cells.

    PubMed

    Ohno, Rika; Nakayama, Megumi; Naruse, Chie; Okashita, Naoki; Takano, Osamu; Tachibana, Makoto; Asano, Masahide; Saitou, Mitinori; Seki, Yoshiyuki

    2013-07-01

    Germline cells reprogramme extensive epigenetic modifications to ensure the cellular totipotency of subsequent generations and to prevent the accumulation of epimutations. Notably, primordial germ cells (PGCs) erase genome-wide DNA methylation and H3K9 dimethylation marks in a stepwise manner during migration and gonadal periods. In this study, we profiled DNA and histone methylation on transposable elements during PGC development, and examined the role of DNA replication in DNA demethylation in gonadal PGCs. CpGs in short interspersed nuclear elements (SINEs) B1 and B2 were substantially demethylated in migrating PGCs, whereas CpGs in long interspersed nuclear elements (LINEs), such as LINE-1, were resistant to early demethylation. By contrast, CpGs in both LINE-1 and SINEs were rapidly demethylated in gonadal PGCs. Four major modifiers of DNA and histone methylation, Dnmt3a, Dnmt3b, Glp and Uhrf1, were actively repressed at distinct stages of PGC development. DNMT1 was localised at replication foci in nascent PGCs, whereas the efficiency of recruitment of DNMT1 into replication foci was severely impaired in gonadal PGCs. Hairpin bisulphite sequencing analysis showed that strand-specific hemi-methylated CpGs on LINE-1 were predominant in gonadal PGCs. Furthermore, DNA demethylation in SINEs and LINE-1 was impaired in Cbx3-deficient PGCs, indicating abnormalities in G1 to S phase progression. We propose that PGCs employ active and passive mechanisms for efficient and widespread erasure of genomic DNA methylation.

  15. Licensing of Primordial Germ Cells for Gametogenesis Depends on Genital Ridge Signaling

    PubMed Central

    Hu, Yueh-Chiang; Nicholls, Peter K.; Soh, Y. Q. Shirleen; Daniele, Joseph R.; Junker, Jan Philipp; van Oudenaarden, Alexander; Page, David C.

    2015-01-01

    In mouse embryos at mid-gestation, primordial germ cells (PGCs) undergo licensing to become gametogenesis-competent cells (GCCs), gaining the capacity for meiotic initiation and sexual differentiation. GCCs then initiate either oogenesis or spermatogenesis in response to gonadal cues. Germ cell licensing has been considered to be a cell-autonomous and gonad-independent event, based on observations that some PGCs, having migrated not to the gonad but to the adrenal gland, nonetheless enter meiosis in a time frame parallel to ovarian germ cells -- and do so regardless of the sex of the embryo. Here we test the hypothesis that germ cell licensing is cell-autonomous by examining the fate of PGCs in Gata4 conditional mutant (Gata4 cKO) mouse embryos. Gata4, which is expressed only in somatic cells, is known to be required for genital ridge initiation. PGCs in Gata4 cKO mutants migrated to the area where the genital ridge, the precursor of the gonad, would ordinarily be formed. However, these germ cells did not undergo licensing and instead retained characteristics of PGCs. Our results indicate that licensing is not purely cell-autonomous but is induced by the somatic genital ridge. PMID:25739037

  16. Licensing of primordial germ cells for gametogenesis depends on genital ridge signaling.

    PubMed

    Hu, Yueh-Chiang; Nicholls, Peter K; Soh, Y Q Shirleen; Daniele, Joseph R; Junker, Jan Philipp; van Oudenaarden, Alexander; Page, David C

    2015-03-01

    In mouse embryos at mid-gestation, primordial germ cells (PGCs) undergo licensing to become gametogenesis-competent cells (GCCs), gaining the capacity for meiotic initiation and sexual differentiation. GCCs then initiate either oogenesis or spermatogenesis in response to gonadal cues. Germ cell licensing has been considered to be a cell-autonomous and gonad-independent event, based on observations that some PGCs, having migrated not to the gonad but to the adrenal gland, nonetheless enter meiosis in a time frame parallel to ovarian germ cells -- and do so regardless of the sex of the embryo. Here we test the hypothesis that germ cell licensing is cell-autonomous by examining the fate of PGCs in Gata4 conditional mutant (Gata4 cKO) mouse embryos. Gata4, which is expressed only in somatic cells, is known to be required for genital ridge initiation. PGCs in Gata4 cKO mutants migrated to the area where the genital ridge, the precursor of the gonad, would ordinarily be formed. However, these germ cells did not undergo licensing and instead retained characteristics of PGCs. Our results indicate that licensing is not purely cell-autonomous but is induced by the somatic genital ridge.

  17. Progress towards human primordial germ cell specification in vitro.

    PubMed

    Canovas, S; Campos, R; Aguilar, E; Cibelli, J B

    2017-01-01

    Primordial germ cells (PGCs) have long been considered the link between one generation and the next. PGC specification begins in the early embryo as a result of a highly orchestrated combination of transcriptional and epigenetic mechanisms. Understanding the molecular events that lead to proper PGC development will facilitate the development of new treatments for human infertility as well as species conservation. This article describes the latest, most relevant findings about the mechanisms of PGC formation, emphasizing human PGC. It also discusses our own laboratory's progress in using transdifferentiation protocols to derive human PGCs (hPGCs). Our preliminary results arose from our pursuit of a sequential hPGC induction strategy that starts with the repression of lineage-specific factors in the somatic cell, followed by the reactivation of germ cell-related genes using specific master regulators, which can indeed reactivate germ cell-specific genes in somatic cells. While it is still premature to assume that fully functional human gametes can be obtained in a dish, our results, together with those recently published by others, provide strong evidence that generating their precursors, PGCs, is within reach. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Conservation of migration and differentiation circuits in primordial germ cells between avian species.

    PubMed

    Park, Tae Sub; Han, Jae Yong

    2013-01-01

    Germ cell differentiation in reverse-sexed reproductive organs and interspecies germ line chimeras provides insight into the mechanism of germ cell development and represents a useful tool for conservation of endangered birds. We investigated the migration and survival capacity of male chicken primordial germ cells (PGCs) in female chicken embryos and in quail and Korean ring-necked pheasant embryos of both sexes. Interestingly, the PGCs were successfully reintroduced in all cases. Furthermore, the cells survived in the recipient gonads until hatching regardless of sex and species of the recipient. In the case of male recipient chickens, PGC-derived offspring were produced. However, the reverse-sexed female chickens, quails and pheasants of both sexes did not generate any male donor PGC-derived progeny. These results suggest that migration and survival circuits in chicken PGCs are conserved in both sexes and between avian species during embryonic development.

  19. Conservation of Migration and Differentiation Circuits in Primordial Germ Cells Between Avian Species

    PubMed Central

    PARK, Tae Sub; HAN, Jae Yong

    2013-01-01

    Abstract Germ cell differentiation in reverse-sexed reproductive organs and interspecies germ line chimeras provides insight into the mechanism of germ cell development and represents a useful tool for conservation of endangered birds. We investigated the migration and survival capacity of male chicken primordial germ cells (PGCs) in female chicken embryos and in quail and Korean ring-necked pheasant embryos of both sexes. Interestingly, the PGCs were successfully reintroduced in all cases. Furthermore, the cells survived in the recipient gonads until hatching regardless of sex and species of the recipient. In the case of male recipient chickens, PGC-derived offspring were produced. However, the reverse-sexed female chickens, quails and pheasants of both sexes did not generate any male donor PGC-derived progeny. These results suggest that migration and survival circuits in chicken PGCs are conserved in both sexes and between avian species during embryonic development. PMID:23386102

  20. Cryopreservation of specialized chicken lines using cultured primordial germ cells.

    PubMed

    Nandi, S; Whyte, J; Taylor, L; Sherman, A; Nair, V; Kaiser, P; McGrew, M J

    2016-08-01

    Biosecurity and sustainability in poultry production requires reliable germplasm conservation. Germplasm conservation in poultry is more challenging in comparison to other livestock species. Embryo cryopreservation is not feasible for egg-laying animals, and chicken semen conservation has variable success for different chicken breeds. A potential solution is the cryopreservation of the committed diploid stem cell precursors to the gametes, the primordial germ cells ( PGCS: ). Primordial germ cells are the lineage-restricted cells found at early embryonic stages in birds and form the sperm and eggs. We demonstrate here, using flocks of partially inbred, lower-fertility, major histocompatibility complex- ( MHC-: ) restricted lines of chicken, that we can easily derive and cryopreserve a sufficient number of independent lines of male and female PGCs that would be sufficient to reconstitute a poultry breed. We demonstrate that germ-line transmission can be attained from these PGCs using a commercial layer line of chickens as a surrogate host. This research is a major step in developing and demonstrating that cryopreserved PGCs could be used for the biobanking of specialized flocks of birds used in research settings. The prospective application of this technology to poultry production will further increase sustainability to meet current and future production needs. © The Author 2016. Published by Oxford University Press on behalf of Poultry Science Association.

  1. Flow cytometric analysis of apoptosis in cryoconserved chicken primordial germ cells.

    PubMed

    Sawicka, Dorota; Chojnacka-Puchta, Luiza; Zielinski, Marcin; Plucienniczak, Grazyna; Plucienniczak, Andrzej; Bednarczyk, Marek

    2015-03-01

    Our research aimed to compare the effects of four cryoprotectants and four slow freezing programs on the viability and apoptosis of primordial germ cells (PGCs) in vitro. PGCs were collected from chicken embryonic blood at Hamburger and Hamilton (HH) stages 14-16 and purified by Percoll density gradient centrifugation and then subjected to cryopreservation. We applied microscopy to determine the survival of PGCs after trypan blue staining and flow cytometry to examine apoptosis and viability after annexin V kit staining. We also examined the functionality of cryopreserved PGCs in vivo. Significant differences in viability of PGCs determined via microscopy and flow cytometry were observed. The most unfavorable combination for slow freezing PGCs was program 3 and MIX H (10% DMSO and 5% glycerol in Hank's solution supplemented with 10% FBS) as the cryoprotectant (48.43 and 15.37% live and early apoptotic PGCs, respectively). The highest average percentage of live PGCs (93.1%) and the lowest percentage of early apoptotic PGCs (6.5%) were achieved by slow freezing PGCs in the presence of DMSO F (10% DMSO in FBS) via program 1. Therefore, this method was chosen for the in vivo test. Cryopreserved (group 1) and freshly isolated (group 2) PGCs were transfectedwith a pEGFP-N1 plasmid, cultured under antibiotic selection, and then injected into 3-day-old embryos. After 5 days of incubation, we identified the EGFP marker gene in the gonads of 40 and 45% of recipients in groups 1 and 2, respectively. This is the first study to apply flow cytometry to examine the apoptosis and viability of cryopreserved PGCs. The in vitro and in vivo findings showed that the developed PGC cryoconservation method, depending on slow freezing at the rate of 2°C/min (program 1) in the presence of 10% DMSO F, is an improvement over previous cryoconservation methods and may be a useful tool for the ex situ strategy of poultry biodiversity preservation.

  2. Reproduction of wild birds via interspecies germ cell transplantation.

    PubMed

    Kang, Seok Jin; Choi, Jin Won; Kim, Sun Young; Park, Kyung Je; Kim, Tae Min; Lee, Young Mok; Kim, Heebal; Lim, Jeong Mook; Han, Jae Yong

    2008-11-01

    The present study was conducted to apply an interspecies germ cell transfer technique to wild bird reproduction. Pheasant (Phasianus colchicus) primordial germ cells (PGCs) retrieved from the gonads of 7-day-old embryos were transferred to the bloodstream of 2.5-day-old chicken (Gallus gallus) embryos. Pheasant-to-chicken germline chimeras hatched from the recipient embryos, and 10 pheasants were derived from testcross reproduction of the male chimeras with female pheasants. Gonadal migration of the transferred PGCs, their involvement in spermatogenesis, and production of chimeric semen were confirmed. The phenotype of pheasant progenies derived from the interspecies transfer was identical to that of wild pheasants. The average efficiency of reproduction estimated from the percentage of pheasants to total progenies was 17.5%. In conclusion, interspecies germ cell transfer into a developing embryo can be used for wild bird reproduction, and this reproductive technology may be applicable in conserving endangered bird species.

  3. Direct Reprogramming of Human Primordial Germ Cells into Induced Pluripotent Stem Cells: Efficient Generation of Genetically Engineered Germ Cells

    PubMed Central

    Bazley, Faith A.; Liu, Cyndi F.; Yuan, Xuan; Hao, Haiping; All, Angelo H.; De Los Angeles, Alejandro; Zambidis, Elias T.; Gearhart, John D.

    2015-01-01

    Abstract Primordial germ cells (PGCs) share many properties with embryonic stem cells (ESCs) and innately express several key pluripotency-controlling factors, including OCT4, NANOG, and LIN28. Therefore, PGCs may provide a simple and efficient model for studying somatic cell reprogramming to induced pluripotent stem cells (iPSCs), especially in determining the regulatory mechanisms that fundamentally define pluripotency. Here, we report a novel model of PGC reprogramming to generate iPSCs via transfection with SOX2 and OCT4 using integrative lentiviral. We also show the feasibility of using nonintegrative approaches for generating iPSC from PGCs using only these two factors. We show that human PGCs express endogenous levels of KLF4 and C-MYC protein at levels similar to embryonic germ cells (EGCs) but lower levels of SOX2 and OCT4. Transfection with both SOX2 and OCT4 together was required to induce PGCs to a pluripotent state at an efficiency of 1.71%, and the further addition of C-MYC increased the efficiency to 2.33%. Immunohistochemical analyses of the SO-derived PGC-iPSCs revealed that these cells were more similar to ESCs than EGCs regarding both colony morphology and molecular characterization. Although leukemia inhibitory factor (LIF) was not required for the generation of PGC-iPSCs like EGCs, the presence of LIF combined with ectopic exposure to C-MYC yielded higher efficiencies. Additionally, the SO-derived PGC-iPSCs exhibited differentiation into representative cell types from all three germ layers in vitro and successfully formed teratomas in vivo. Several lines were generated that were karyotypically stable for up to 24 subcultures. Their derivation efficiency and survival in culture significantly supersedes that of EGCs, demonstrating their utility as a powerful model for studying factors regulating pluripotency in future studies. PMID:26154167

  4. Direct Reprogramming of Human Primordial Germ Cells into Induced Pluripotent Stem Cells: Efficient Generation of Genetically Engineered Germ Cells.

    PubMed

    Bazley, Faith A; Liu, Cyndi F; Yuan, Xuan; Hao, Haiping; All, Angelo H; De Los Angeles, Alejandro; Zambidis, Elias T; Gearhart, John D; Kerr, Candace L

    2015-11-15

    Primordial germ cells (PGCs) share many properties with embryonic stem cells (ESCs) and innately express several key pluripotency-controlling factors, including OCT4, NANOG, and LIN28. Therefore, PGCs may provide a simple and efficient model for studying somatic cell reprogramming to induced pluripotent stem cells (iPSCs), especially in determining the regulatory mechanisms that fundamentally define pluripotency. Here, we report a novel model of PGC reprogramming to generate iPSCs via transfection with SOX2 and OCT4 using integrative lentiviral. We also show the feasibility of using nonintegrative approaches for generating iPSC from PGCs using only these two factors. We show that human PGCs express endogenous levels of KLF4 and C-MYC protein at levels similar to embryonic germ cells (EGCs) but lower levels of SOX2 and OCT4. Transfection with both SOX2 and OCT4 together was required to induce PGCs to a pluripotent state at an efficiency of 1.71%, and the further addition of C-MYC increased the efficiency to 2.33%. Immunohistochemical analyses of the SO-derived PGC-iPSCs revealed that these cells were more similar to ESCs than EGCs regarding both colony morphology and molecular characterization. Although leukemia inhibitory factor (LIF) was not required for the generation of PGC-iPSCs like EGCs, the presence of LIF combined with ectopic exposure to C-MYC yielded higher efficiencies. Additionally, the SO-derived PGC-iPSCs exhibited differentiation into representative cell types from all three germ layers in vitro and successfully formed teratomas in vivo. Several lines were generated that were karyotypically stable for up to 24 subcultures. Their derivation efficiency and survival in culture significantly supersedes that of EGCs, demonstrating their utility as a powerful model for studying factors regulating pluripotency in future studies.

  5. In vitro differentiation of germ cells from stem cells: a comparison between primordial germ cells and in vitro derived primordial germ cell-like cells.

    PubMed

    Ge, W; Chen, C; De Felici, M; Shen, W

    2015-10-15

    Stem cells are unique cell types capable to proliferate, some of them indefinitely, while maintaining the ability to differentiate into a few or any cell lineages. In 2003, a group headed by Hans R. Schöler reported that oocyte-like cells could be produced from mouse embryonic stem (ES) cells in vitro. After more than 10 years, where have these researches reached? Which are the major successes achieved and the problems still remaining to be solved? Although during the last years, many reviews have been published about these topics, in the present work, we will focus on an aspect that has been little considered so far, namely a strict comparison between the in vitro and in vivo developmental capabilities of the primordial germ cells (PGCs) isolated from the embryo and the PGC-like cells (PGC-LCs) produced in vitro from different types of stem cells in the mouse, the species in which most investigation has been carried out. Actually, the formation and differentiation of PGCs are crucial for both male and female gametogenesis, and the faithful production of PGCs in vitro represents the basis for obtaining functional germ cells.

  6. In vitro differentiation of germ cells from stem cells: a comparison between primordial germ cells and in vitro derived primordial germ cell-like cells

    PubMed Central

    Ge, W; Chen, C; De Felici, M; Shen, W

    2015-01-01

    Stem cells are unique cell types capable to proliferate, some of them indefinitely, while maintaining the ability to differentiate into a few or any cell lineages. In 2003, a group headed by Hans R. Schöler reported that oocyte-like cells could be produced from mouse embryonic stem (ES) cells in vitro. After more than 10 years, where have these researches reached? Which are the major successes achieved and the problems still remaining to be solved? Although during the last years, many reviews have been published about these topics, in the present work, we will focus on an aspect that has been little considered so far, namely a strict comparison between the in vitro and in vivo developmental capabilities of the primordial germ cells (PGCs) isolated from the embryo and the PGC-like cells (PGC-LCs) produced in vitro from different types of stem cells in the mouse, the species in which most investigation has been carried out. Actually, the formation and differentiation of PGCs are crucial for both male and female gametogenesis, and the faithful production of PGCs in vitro represents the basis for obtaining functional germ cells. PMID:26469955

  7. NUP50 is necessary for the survival of primordial germ cells in mouse embryos.

    PubMed

    Park, Eunsook; Lee, Bobae; Clurman, Bruce E; Lee, Keesook

    2016-01-01

    Nucleoporin 50 kDa (NUP50), a component of the nuclear pore complex, is highly expressed in male germ cells, but its role in germ cells is largely unknown. In this study, we analyzed the expression and function of NUP50 during the embryonic development of germ cells using NUP50-deficient mice. NUP50 was expressed in germ cells of both sexes at embryonic day 15.5 (E15.5), E13.5, and E12.5. In addition, NUP50 expression was also detected in primordial germ cells (PGCs) migrating into the genital ridges at E9.5. The gonads of Nup50-/- embryos of both sexes contained few PGCs at both E11.5 and E12.5 and no developing germ cells at E15.5. The migratory PGCs in Nup50-/- embryos at E9.5 showed increased apoptosis but a normal rate of proliferation, resulting in the progressive loss of germ cells at later stages. Taken together, these results suggest that NUP50 plays an essential role in the survival of PGCs during embryonic development. © 2016 Society for Reproduction and Fertility.

  8. Deadenylase depletion protects inherited mRNAs in primordial germ cells.

    PubMed

    Swartz, S Zachary; Reich, Adrian M; Oulhen, Nathalie; Raz, Tal; Milos, Patrice M; Campanale, Joseph P; Hamdoun, Amro; Wessel, Gary M

    2014-08-01

    A crucial event in animal development is the specification of primordial germ cells (PGCs), which become the stem cells that create sperm and eggs. How PGCs are created provides a valuable paradigm for understanding stem cells in general. We find that the PGCs of the sea urchin Strongylocentrotus purpuratus exhibit broad transcriptional repression, yet enrichment for a set of inherited mRNAs. Enrichment of several germline determinants in the PGCs requires the RNA-binding protein Nanos to target the transcript that encodes CNOT6, a deadenylase, for degradation in the PGCs, thereby creating a stable environment for RNA. Misexpression of CNOT6 in the PGCs results in their failure to retain Seawi transcripts and Vasa protein. Conversely, broad knockdown of CNOT6 expands the domain of Seawi RNA as well as exogenous reporters. Thus, Nanos-dependent spatially restricted CNOT6 differential expression is used to selectively localize germline RNAs to the PGCs. Our findings support a 'time capsule' model of germline determination, whereby the PGCs are insulated from differentiation by retaining the molecular characteristics of the totipotent egg and early embryo.

  9. Epigenetic regulation during the differentiation of stem cells to germ cells.

    PubMed

    Sun, Yuan-Chao; Wang, Yong-Yong; Ge, Wei; Cheng, Shun-Feng; Dyce, Paul W; Shen, Wei

    2017-08-22

    Gametogenesis is an essential process to ensure the transfer of genetic information from one generation to the next. It also provides a mechanism by which genetic evolution can take place. Although the genome of primordial germ cells (PGCs) is exactly the same with somatic cells within an organism, there are significant differences between their developments. For example, PGCs eventually undergo meiosis to become functional haploid gametes, and prior to that they undergo epigenetic imprinting which greatly alter their genetic regulation. Epigenetic imprinting of PGCs involves the erasure of DNA methylation and the reestablishment of them during sperm and oocyte formation. These processes are necessary and important during gametogenesis. Also, histone modification and X-chromosome inactivation have important roles during germ cell development. Recently, several studies have reported that functional sperm or oocytes can be derived from stem cells in vivo or in vitro. To produce functional germ cells, induction of germ cells from stem cells must recapitulate these processes similar to endogenous germ cells, such as epigenetic modifications. This review focuses on the epigenetic regulation during the process of germ cell development and discusses their importance during the differentiation from stem cells to germ cells.

  10. Epigenetic regulation during the differentiation of stem cells to germ cells

    PubMed Central

    Ge, Wei; Cheng, Shun-Feng; Dyce, Paul W.; Shen, Wei

    2017-01-01

    Gametogenesis is an essential process to ensure the transfer of genetic information from one generation to the next. It also provides a mechanism by which genetic evolution can take place. Although the genome of primordial germ cells (PGCs) is exactly the same with somatic cells within an organism, there are significant differences between their developments. For example, PGCs eventually undergo meiosis to become functional haploid gametes, and prior to that they undergo epigenetic imprinting which greatly alter their genetic regulation. Epigenetic imprinting of PGCs involves the erasure of DNA methylation and the reestablishment of them during sperm and oocyte formation. These processes are necessary and important during gametogenesis. Also, histone modification and X-chromosome inactivation have important roles during germ cell development. Recently, several studies have reported that functional sperm or oocytes can be derived from stem cells in vivo or in vitro. To produce functional germ cells, induction of germ cells from stem cells must recapitulate these processes similar to endogenous germ cells, such as epigenetic modifications. This review focuses on the epigenetic regulation during the process of germ cell development and discusses their importance during the differentiation from stem cells to germ cells. PMID:28915715

  11. Derivation of primordial germ cells from human embryonic and induced pluripotent stem cells is significantly improved by coculture with human fetal gonadal cells.

    PubMed

    Park, Tae Sub; Galic, Zoran; Conway, Anne E; Lindgren, Anne; van Handel, Benjamin J; Magnusson, Mattias; Richter, Laura; Teitell, Michael A; Mikkola, Hanna K A; Lowry, William E; Plath, Kathrin; Clark, Amander T

    2009-04-01

    The derivation of germ cells from human embryonic stem cells (hESCs) or human induced pluripotent stem (hIPS) cells represents a desirable experimental model and potential strategy for treating infertility. In the current study, we developed a triple biomarker assay for identifying and isolating human primordial germ cells (PGCs) by first evaluating human PGC formation during the first trimester in vivo. Next, we applied this technology to characterizing in vitro derived PGCs (iPGCs) from pluripotent cells. Our results show that codifferentiation of hESCs on human fetal gonadal stromal cells significantly improves the efficiency of generating iPGCs. Furthermore, the efficiency was comparable between various pluripotent cell lines regardless of origin from the inner cell mass of human blastocysts (hESCs), or reprogramming of human skin fibroblasts (hIPS). To better characterize the iPGCs, we performed Real-time polymerase chain reaction, microarray, and bisulfite sequencing. Our results show that iPGCs at day 7 of differentiation are transcriptionally distinct from the somatic cells, expressing genes associated with pluripotency and germ cell development while repressing genes associated with somatic differentiation (specifically multiple HOX genes). Using bisulfite sequencing, we show that iPGCs initiate imprint erasure from differentially methylated imprinted regions by day 7 of differentiation. However, iPGCs derived from hIPS cells do not initiate imprint erasure as efficiently. In conclusion, our results indicate that triple positive iPGCs derived from pluripotent cells differentiated on hFGS cells correspond to committed first trimester germ cells (before 9 weeks) that have initiated the process of imprint erasure.

  12. Ror2 Enhances Polarity and Directional Migration of Primordial Germ Cells

    PubMed Central

    Kissner, Michael D.; Zhou, Xin; Anderson, Kathryn V.

    2011-01-01

    The trafficking of primordial germ cells (PGCs) across multiple embryonic structures to the nascent gonads ensures the transmission of genetic information to the next generation through the gametes, yet our understanding of the mechanisms underlying PGC migration remains incomplete. Here we identify a role for the receptor tyrosine kinase-like protein Ror2 in PGC development. In a Ror2 mouse mutant we isolated in a genetic screen, PGC migration and survival are dysregulated, resulting in a diminished number of PGCs in the embryonic gonad. A similar phenotype in Wnt5a mutants suggests that Wnt5a acts as a ligand to Ror2 in PGCs, although we do not find evidence that WNT5A functions as a PGC chemoattractant. We show that cultured PGCs undergo polarization, elongation, and reorientation in response to the chemotactic factor SCF (secreted KitL), whereas Ror2 PGCs are deficient in these SCF-induced responses. In the embryo, migratory PGCs exhibit a similar elongated geometry, whereas their counterparts in Ror2 mutants are round. The protein distribution of ROR2 within PGCs is asymmetric, both in vitro and in vivo; however, this asymmetry is lost in Ror2 mutants. Together these results indicate that Ror2 acts autonomously to permit the polarized response of PGCs to KitL. We propose a model by which Wnt5a potentiates PGC chemotaxis toward secreted KitL by redistribution of Ror2 within the cell. PMID:22216013

  13. bFGF signaling-mediated reprogramming of porcine primordial germ cells.

    PubMed

    Zhang, Yu; Ma, Jing; Li, Hai; Lv, Jiawei; Wei, Renyue; Cong, Yimei; Liu, Zhonghua

    2016-05-01

    Primordial germ cells (PGCs) have the ability to be reprogrammed into embryonic germ cells (EGCs) in vitro and are an alternative source of embryonic stem cells. Other than for the mouse, the systematic characterization of mammalian PGCs is still lacking, especially the process by which PGCs convert to pluripotency. This hampers the understanding of germ cell development and the derivation of authenticated EGCs from other species. We observed the morphological development of the genital ridge from Bama miniature pigs and found primary sexual differentiation in the E28 porcine embryo, coinciding with Blimp1 nuclear exclusion in PGCs. To explore molecular events involved in porcine PGC reprogramming, transcriptome data of porcine EGCs and fetal fibroblasts (FFs) were assembled and 1169 differentially expressed genes were used for Gene Ontology analysis. These genes were significantly enriched in cell-surface receptor-linked signal transduction, in agreement with the activation of LIF/Stat3 signaling and FGF signaling during the derivation of porcine EG-like cells. Using a growth-factor-defined culture system, we explored the effects of bFGF on the process and found that bFGF not only functioned at the very beginning of PGC dedifferentiation by impeding Blimp1 nuclear expression via a PI3K/AKT-dependent pathway but also maintained the viability of cultured PGCs thereafter. These results provide further insights into the development of germ cells from livestock and the mechanism of porcine PGC reprogramming.

  14. Regulatory elements and transcriptional control of chicken vasa homologue (CVH) promoter in chicken primordial germ cells.

    PubMed

    Jin, So Dam; Lee, Bo Ram; Hwang, Young Sun; Lee, Hong Jo; Rim, Jong Seop; Han, Jae Yong

    2017-01-01

    Primordial germ cells (PGCs), the precursors of functional gametes, have distinct characteristics and exhibit several unique molecular mechanisms to maintain pluripotency and germness in comparison to somatic cells. They express germ cell-specific RNA binding proteins (RBPs) by modulating tissue-specific cis- and trans-regulatory elements. Studies on gene structures of chicken vasa homologue (CVH), a chicken RNA binding protein, involved in temporal and spatial regulation are thus important not only for understanding the molecular mechanisms that regulate germ cell fate, but also for practical applications of primordial germ cells. However, very limited studies are available on regulatory elements that control germ cell-specific expression in chicken. Therefore, we investigated the intricate regulatory mechanism(s) that governs transcriptional control of CVH. We constructed green fluorescence protein (GFP) or luciferase reporter vectors containing the various 5' flanking regions of CVH gene. From the 5' deletion and fragmented assays in chicken PGCs, we have identified a CVH promoter that locates at -316 to +275 base pair fragment with the highest luciferase activity. Additionally, we confirmed for the first time that the 5' untranslated region (UTR) containing intron 1 is required for promoter activity of the CVH gene in chicken PGCs. Furthermore, using a transcription factor binding prediction, transcriptome analysis and siRNA-mediated knockdown, we have identified that a set of transcription factors play a role in the PGC-specific CVH gene expression. These results demonstrate that cis-elements and transcription factors localizing in the 5' flanking region including the 5' UTR and an intron are important for transcriptional regulation of the CVH gene in chicken PGCs. Finally, this information will contribute to research studies in areas of reproductive biology, constructing of germ cell-specific synthetic promoter for tracing primordial germ cells as well as

  15. Transient and stable GFP expression in germ cells by the vasa regulatory sequences from the red seabream (Pagrus major).

    PubMed

    Lin, Fan; Liu, Qinghua; Li, Mingyou; Li, Zhendong; Hong, Ni; Li, Jun; Hong, Yunhan

    2012-01-01

    Primordial germ cells (PGCs) are the precursors of gametes responsible for genetic transmission to the next generation. They provide an ideal system for cryopreservation and restoration of biodiversity. Recently, considerable attention has been raised to visualize, isolate and transplant PGCs within and between species. In fish, stable PGC visualization in live embryo and individual has been limited to laboratory fish models such as medaka and zebrafish. One exception is the rainbow trout, which represents the only species with aquaculture importance and has GFP-labeled germ cells throughout development. PGCs can be transiently labeled by embryonic injection of mRNA containing green fluorescence protein gene (GFP) and 3'-untranslated region (3'-UTR) of a maternal germ gene such as vasa, nos1, etc. Stable PGC labeling can be achieved through production of transgenic animals by some transcriptional regulatory sequences from germ genes, such as the vasa promoter and 3'-UTR. In this study, we reported the functional analyses of the red seabream vasa (Pmvas) regulatory sequences, using medaka as a model system. It was showed that injection of GFP-Pmvas3'UTR mRNA was able to label medaka PGCs during embryogenesis. Besides, we have constructed pPmvasGFP transgenic vector, and established a stable transgenic medaka line exhibiting GFP expression in germ cells including PGCs, mitotic and meiotic germ cells of both sexes, under control of the Pmvas transcriptional regulatory sequences. It is concluded that the Pmvas regulatory sequences examined in this study are sufficient for germ cell expression and labeling.

  16. Pluripotent stem cells derived from mouse primordial germ cells by small molecule compounds.

    PubMed

    Kimura, Tohru; Kaga, Yoshiaki; Sekita, Yoichi; Fujikawa, Keita; Nakatani, Tsunetoshi; Odamoto, Mika; Funaki, Soichiro; Ikawa, Masahito; Abe, Kuniya; Nakano, Toru

    2015-01-01

    Primordial germ cells (PGCs) can give rise to pluripotent stem cells known as embryonic germ cells (EGCs) when cultured with basic fibroblast growth factor (bFGF), stem cell factor (SCF), and leukemia inhibitory factor. Somatic cells can give rise to induced pluripotent stem cells (iPSCs) by introduction of the reprogramming transcription factors Oct4, Sox2, and Klf4. The effects of Sox2 and Klf4 on somatic cell reprogramming can be reproduced using the small molecule compounds, transforming growth factor-β receptor (TGFβR) inhibitor and Kempaullone, respectively. Here we examined the effects of TGFβR inhibitor and Kempaullone on EGC derivation from PGCs. Treatment of PGCs with TGFβR inhibitor and/or Kempaullone generated pluripotent stem cells under standard embryonic stem cell (ESC) culture conditions without bFGF and SCF, which we termed induced EGCs (iEGCs). The derivation efficiency of iEGCs was dependent on the differentiation stage and sex. DNA methylation levels of imprinted genes in iEGCs were reduced, with the exception of the H19 gene. The promoters of genes involved in germline development were generally hypomethylated in PGCs, but three germline genes showed comparable DNA methylation levels among iEGs, ESCs, and iPSCs. These results show that PGCs can be reprogrammed into pluripotent state using small molecule compounds, and that DNA methylation of these germline genes is not maintained in iEGCs.

  17. The ability of mouse nuclear transfer embryonic stem cells to differentiate into primordial germ cells.

    PubMed

    Mansouri, Vahid; Salehi, Mohammad; Nourozian, Mohsen; Fadaei, Fatemeh; Farahani, Reza Mastery; Piryaei, Abbas; Delbari, Ali

    2015-05-01

    Nuclear transfer embryonic stem cells (ntESCs) show stem cell characteristics such as pluripotency but cause no immunological disorders. Although ntESCs are able to differentiate into somatic cells, the ability of ntESCs to differentiate into primordial germ cells (PGCs) has not been examined. In this work, we examined the capacity of mouse ntESCs to differentiate into PGCs in vitro. ntESCs aggregated to form embryoid bodies (EB) in EB culture medium supplemented with bone morphogenetic protein 4(BMP4) as the differentiation factor. The expression level of specific PGC genes was compared at days 4 and 8 using real time PCR. Flow cytometry and immunocytochemical staining were used to detect Mvh as a specific PGC marker. ntESCs expressed particular genes related to different stages of PGC development. Flow cytometry and immunocytochemical staining confirmed the presence of Mvh protein in a small number of cells. There were significant differences between cells that differentiated into PGCs in the group treated with Bmp4 compared to non-treated cells. These findings indicate that ntESCs can differentiate into putative PGCs. Improvement of ntESC differentiation into PGCs may be a reliable means of producing mature germ cells.

  18. [An initial investigation on the in vitro culture system of primordial germ cells in golden hamsters].

    PubMed

    Li, Hong; Zhang, Hao; Liang, Ying; Zhan, Li; Wu, Desheng

    2006-06-01

    To establish the in vitro culture system of primordial germ cells (PGCs) of golden hamsters, PGCs of hamster were isolated from genital ridge of embryos at 10. 5th dpc (day post coitum), obtained by enzyme-mechanical method, and cultured on feeder cells. Then the PGCs were identified by alkaline phosphatase (ALP) activity staining. In order to induce the PGCs to differentiate in vitro, we removed the differential inhibition factors in the conditioned medium and observed the formation of embryoids and differentiated cells from three layers. The result showed that the pluripotent primordial germ cells could be successfully obtained from the golden hamsters at 10. 5th dpc by the enzyme-mechanical method and that PGCs were identified by both their strong positive reaction in ALP activity staining test and their differentiation into three-layer derived cells in vitro. The result suggests that the establishment of in vitro PGCs culture system of golden hamsters will provide new cell source for biomedical engineering.

  19. Primordial Germ Cell Specification from Embryonic Stem Cells

    PubMed Central

    Liu, Haisong; Zhang, Donghui; Yang, Weifeng; Deng, Hongkui

    2008-01-01

    Background Primordial germ cell (PGC) specification is the first crucial step in germ line development. However, owing to significant challenges regarding the in vivo system, such as the complex cellular environment and potential problems with embryo manipulation, it is desirable to generate embryonic stem (ES) cells that are capable of overcoming these aforementioned limitations in order to provide a potential in vitro model to recapitulate the developmental processes in vivo. Methodology and Principal Findings Here, we studied the detailed process of PGC specification from stella-GFP ES cells. We first observed the heterogeneous expression of stella in ES cells. However, neither Stella-positive ES cells nor Stella-negative ES cells shared a similar gene expression pattern with either PGCs or PGC precursors. Second, we derived PGCs from ES cells using two differentiation methods, namely the attachment culture technique and the embryoid body (EB) method. Compared with PGCs derived via the attachment culture technique, PGCs derived via the EB method that had undergone the sequential erasure of Peg3 followed by Igf2r resulted in a cell line in which the expression dynamics of T, Fgf8 and Sox17, in addition to the expression of the epiblast markers, were more similar to the in vivo expression, thus demonstrating that the process of PGC derivation was more faithfully recapitulated using the EB method. Furthermore, we developed an in vitro model of PGC specification in a completely chemically defined medium (CDM) that indicated that BMP4 and Wnt3a promoted PGC derivation, whereas BMP8b and activinA had no observable effect on PGC derivation. Conclusions and Significance The in vitro model we have established can recapitulate the developmental processes in vivo and provides new insights into the mechanism of PGC specification. PMID:19107197

  20. Primordial germ cell specification from embryonic stem cells.

    PubMed

    Wei, Wei; Qing, Tingting; Ye, Xin; Liu, Haisong; Zhang, Donghui; Yang, Weifeng; Deng, Hongkui

    2008-01-01

    Primordial germ cell (PGC) specification is the first crucial step in germ line development. However, owing to significant challenges regarding the in vivo system, such as the complex cellular environment and potential problems with embryo manipulation, it is desirable to generate embryonic stem (ES) cells that are capable of overcoming these aforementioned limitations in order to provide a potential in vitro model to recapitulate the developmental processes in vivo. Here, we studied the detailed process of PGC specification from stella-GFP ES cells. We first observed the heterogeneous expression of stella in ES cells. However, neither Stella-positive ES cells nor Stella-negative ES cells shared a similar gene expression pattern with either PGCs or PGC precursors. Second, we derived PGCs from ES cells using two differentiation methods, namely the attachment culture technique and the embryoid body (EB) method. Compared with PGCs derived via the attachment culture technique, PGCs derived via the EB method that had undergone the sequential erasure of Peg3 followed by Igf2r resulted in a cell line in which the expression dynamics of T, Fgf8 and Sox17, in addition to the expression of the epiblast markers, were more similar to the in vivo expression, thus demonstrating that the process of PGC derivation was more faithfully recapitulated using the EB method. Furthermore, we developed an in vitro model of PGC specification in a completely chemically defined medium (CDM) that indicated that BMP4 and Wnt3a promoted PGC derivation, whereas BMP8b and activinA had no observable effect on PGC derivation. The in vitro model we have established can recapitulate the developmental processes in vivo and provides new insights into the mechanism of PGC specification.

  1. Chicken stem cell factor enhances primordial germ cell proliferation cooperatively with fibroblast growth factor 2

    PubMed Central

    MIYAHARA, Daichi; OISHI, Isao; MAKINO, Ryuichi; KURUMISAWA, Nozomi; NAKAYA, Ryuma; ONO, Tamao; KAGAMI, Hiroshi; TAGAMI, Takahiro

    2015-01-01

    An in vitro culture system of chicken primordial germ cells (PGCs) has been recently developed, but the growth factor involved in the proliferation of PGCs is largely unknown. In the present study, we investigated the growth effects of chicken stem cell factor (chSCF) on the in vitro proliferation of chicken PGCs. We established two feeder cell lines (buffalo rat liver cells; BRL cells) that stably express the putative secreted form of chSCF (chSCF1-BRL) and membrane bound form of chSCF (chSCF2-BRL). Cultured PGC lines were incubated on chSCF1 or chSCF2-BRL feeder cells with fibroblast growth factor 2 (FGF2), and growth effects of each chSCF isoform were investigated. The in vitro proliferation rate of the PGCs cultured on chSCF2-BRL at 20 days of culture was more than threefold higher than those cultured on chSCF1-BRL cells and more than fivefold higher than those cultured on normal BRL cells. Thus, use of chSCF2-BRL feeder layer was effective for in vitro proliferation of chicken PGCs. However, the acceleration of PGC proliferation on chSCF2-BRL was not observed without FGF2, suggesting that chSCF2 would act as a proliferation co-factor of FGF2. We transferred the PGCs cultured on chSCF2-BRL cells to recipient embryos, generated germline chimeric chickens and assessed the germline competency of cultured PGCs by progeny test. Donor-derived progenies were obtained, and the frequency of germline transmission was 3.39%. The results of this study demonstrate that chSCF2 induces hyperproliferation of chicken PGCs retaining germline competency in vitro in cooperation with FGF2. PMID:26727404

  2. Novel technique for visualizing primordial germ cells in sturgeons (Acipenser ruthenus, A. gueldenstaedtii, A. baerii, and Huso huso).

    PubMed

    Saito, Taiju; Psenicka, Martin

    2015-10-01

    Primordial germ cells (PGCs) are the origin of all germ cells in developing embryos. In the sturgeon embryo, PGCs develop from the vegetal hemisphere, which mainly acts as an extraembryonic source of nutrition. Current methods for studying sturgeon PGCs require either killing the fish or using costly and time-consuming histological procedures. Here, we demonstrate that visualization of sterlet (Acipenser ruthenus>) PGCs in vivo is feasible by simply labeling the vegetal hemisphere with fluorescein isothiocyanate (FITC)-dextran. We injected FITC-dextrans, with molecular weights varying between 10 000 and 2 000 000, into the vegetal pole of 1- to 4-cell stage embryos. At the neurula to tail-bud developmental stages, FITC-positive PGC-like cells appeared ventrally around the developing tail bud in the experimental group that received a high-molecular-weight FITC-dextran. The highest average number of FITC-positive PGC-like cells was observed in embryos injected with FITC-dextran having a molecular weight of 500 000 (FD-500). The pattern of migration of the labeled cells was identical to that of PGCs, clearly indicating that the FITC-positive PGC-like cells were PGCs. Labeled vegetal cells, except for the PGCs, were digested and excreted before the embryos starting feeding. FITC-labeled PGCs were observed in the developing gonads of fish for at least 3 mo after injection. We also found that FD-500 could be used to visualize PGCs in other sturgeon species. To the best of our knowledge, this report is the first to demonstrate in any animal species that PGCs can be visualized in vivo for a long period by the injection of a simple reagent. © 2015 by the Society for the Study of Reproduction, Inc.

  3. Stochastic specification of primordial germ cells from mesoderm precursors in axolotl embryos

    PubMed Central

    Chatfield, Jodie; O'Reilly, Marie-Anne; Bachvarova, Rosemary F.; Ferjentsik, Zoltan; Redwood, Catherine; Walmsley, Maggie; Patient, Roger; Loose, Mathew; Johnson, Andrew D.

    2014-01-01

    A common feature of development in most vertebrate models is the early segregation of the germ line from the soma. For example, in Xenopus and zebrafish embryos primordial germ cells (PGCs) are specified by germ plasm that is inherited from the egg; in mice, Blimp1 expression in the epiblast mediates the commitment of cells to the germ line. How these disparate mechanisms of PGC specification evolved is unknown. Here, in order to identify the ancestral mechanism of PGC specification in vertebrates, we studied PGC specification in embryos from the axolotl (Mexican salamander), a model for the tetrapod ancestor. In the axolotl, PGCs develop within mesoderm, and classic studies have reported their induction from primitive ectoderm (animal cap). We used an axolotl animal cap system to demonstrate that signalling through FGF and BMP4 induces PGCs. The role of FGF was then confirmed in vivo. We also showed PGC induction by Brachyury, in the presence of BMP4. These conditions induced pluripotent mesodermal precursors that give rise to a variety of somatic cell types, in addition to PGCs. Irreversible restriction of the germ line did not occur until the mid-tailbud stage, days after the somatic germ layers are established. Before this, germline potential was maintained by MAP kinase signalling. We propose that this stochastic mechanism of PGC specification, from mesodermal precursors, is conserved in vertebrates. PMID:24917499

  4. Migratory and adhesive properties of Xenopus laevis primordial germ cells in vitro

    PubMed Central

    Dzementsei, Aliaksandr; Schneider, David; Janshoff, Andreas; Pieler, Tomas

    2013-01-01

    Summary The directional migration of primordial germ cells (PGCs) to the site of gonad formation is an advantageous model system to study cell motility. The embryonic development of PGCs has been investigated in different animal species, including mice, zebrafish, Xenopus and Drosophila. In this study we focus on the physical properties of Xenopus laevis PGCs during their transition from the passive to the active migratory state. Pre-migratory PGCs from Xenopus laevis embryos at developmental stages 17–19 to be compared with migratory PGCs from stages 28–30 were isolated and characterized in respect to motility and adhesive properties. Using single-cell force spectroscopy, we observed a decline in adhesiveness of PGCs upon reaching the migratory state, as defined by decreased attachment to extracellular matrix components like fibronectin, and a reduced adhesion to somatic endodermal cells. Data obtained from qPCR analysis with isolated PGCs reveal that down-regulation of E-cadherin might contribute to this weakening of cell-cell adhesion. Interestingly, however, using an in vitro migration assay, we found that movement of X. laevis PGCs can also occur independently of specific interactions with their neighboring cells. The reduction of cellular adhesion during PGC development is accompanied by enhanced cellular motility, as reflected in increased formation of bleb-like protrusions and inferred from electric cell-substrate impedance sensing (ECIS) as well as time-lapse image analysis. Temporal alterations in cell shape, including contraction and expansion of the cellular body, reveal a higher degree of cellular dynamics for the migratory PGCs in vitro. PMID:24285703

  5. Discrete somatic niches coordinate proliferation and migration of primordial germ cells via Wnt signaling

    PubMed Central

    Cantú, Andrea V.; Altshuler-Keylin, Svetlana

    2016-01-01

    Inheritance depends on the expansion of a small number of primordial germ cells (PGCs) in the early embryo. Proliferation of mammalian PGCs is concurrent with their movement through changing microenvironments; however, mechanisms coordinating these conflicting processes remain unclear. Here, we find that PGC proliferation varies by location rather than embryonic age. Ror2 and Wnt5a mutants with mislocalized PGCs corroborate the microenvironmental regulation of the cell cycle, except in the hindgut, where Wnt5a is highly expressed. Molecular and genetic evidence suggests that Wnt5a acts via Ror2 to suppress β-catenin–dependent Wnt signaling in PGCs and limit their proliferation in specific locations, which we validate by overactivating β-catenin in PGCs. Our results suggest that the balance between expansion and movement of migratory PGCs is fine-tuned in different niches by the opposing β-catenin–dependent and Ror2-mediated pathways through Wnt5a. This could serve as a selective mechanism to favor early and efficient migrators with clonal dominance in the ensuing germ cell pool while penalizing stragglers. PMID:27402951

  6. Proliferation in culture of primordial germ cells derived from embryonic stem cell: induction by retinoic acid

    PubMed Central

    Makoolati, Zohreh; Movahedin, Mansoureh; Forouzandeh-Moghadam, Mehdi

    2016-01-01

    An in vitro system that supports primordial germ cells (PGCs) survival and proliferation is useful for enhancement of these cells and efficient transplantation in infertility disorders. One approach is cultivation of PGCs under proper conditions that allow self-renewal and proliferation of PGCs. For this purpose, we compared the effects of different concentrations of retinoic acid (RA), and the effect of PGCs co-culture (Co-C) with SIM mouse embryo-derived thioguanine- and ouabain-resistant (STO) cells on the proliferation of embryonic stem cells (ESCs)-derived PGCs. One-day-old embryoid body (EB) was cultured for 4 days in simple culture system in the presence of 5 ng/ml bone morphogenetic protein-4 (BMP4) (SCB group) for PGC induction. For PGC enrichment, ESCs-derived germ cells were cultured for 7 days in the presence of different doses (0–5  μM) of RA, both in the simple and STO Co-C systems. At the end of the culture period, viability and proliferation rates were assessed and expression of mouse vasa homologue (Mvh),  α6 integrin,  β1 integrin, stimulated by retinoic acid 8 (Stra8) and piwi (Drosophila)-like 2 (Piwil2) was evaluated using quantitative PCR. Also, the inductive effects were investigated immunocytochemically with Mvh and cadherin1 (CDH1) on the selected groups. Immunocytochemistry/PCR results showed higher expression of Mvh, the PGC-specific marker, in 3  μM RA concentrations on the top of the STO feeder layer. Meanwhile, assessment of the Stra8 mRNA and CDH1 protein, the specific makers for spermatogonia, showed no significant differences between groups. Based on the results, it seems that in the presence of 3 μM RA on top of the STO feeder layer cells, the majority of the cells transdifferentiated into germ cells were PGCs. PMID:27834666

  7. Sexual dimorphic expression of dnd in germ cells during sex reversal and its requirement for primordial germ cell survival in protogynous hermaphroditic grouper.

    PubMed

    Sun, Zhi-Hui; Zhou, Li; Li, Zhi; Liu, Xiao-Chun; Li, Shui-Sheng; Wang, Yang; Gui, Jian-Fang

    2017-06-01

    Dead end (dnd), vertebrate-specific germ cell marker, had been demonstrated to be essential for primordial germ cell (PGC) migration and survival, and the link between PGC number and sex change had been revealed in some teleost species, but little is known about dnd in hermaphroditic vertebrates. In the present study, a protogynous hermaphroditic orange-spotted grouper (Epinephelus coioides) dnd homologue (Ecdnd) was identified and characterized. Quantitative real-time PCR and in situ hybridization analysis revealed a dynamic and sexually dimorphic expression pattern in PGCs and germ cells of gonads. During sex changing, the Ecdnd transcript sharply increased in early transitional gonad, reached the highest level at late transitional gonad stage, and decreased after testis maturation. Visualization of zebrafish PGCs by injecting with RFP-Ecdnd-3'UTR RNA and GFP-zfnanos3-3'UTR RNA confirmed importance of Ecdnd 3'UTR for the PGC distribution. In addition, knockdown of EcDnd by using antisense morpholinos (MO) caused the ablation of PGCs in orange-spotted grouper. Therefore, the current data indicate that Ecdnd is essential for PGCs survival and may serve as a useful germ cell marker during gametogenesis in hermaphroditic grouper. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. mRNA translation during oocyte maturation plays a key role in development of primordial germ cells in Xenopus embryos.

    PubMed

    Zeynali, Bahman; Dixon, Keith E

    2004-09-01

    It is believed that cytoplasmic localization in the egg is necessary for development of primordial germ cells (PGCs) in Xenopus embryos. In this study, we sought to determine if translation of maternal mRNA during oocyte maturation is involved in the development of PGCs. Donor oocytes were collected from both stimulated (those who receive gonadotropin) and unstimulated females, artificially matured and fertilized using a host transfer technique. Using chloramphenicol (50 microM and 500 microM RNA), RNA translation was inhibited during oocyte maturation. Our results showed that in unstimulated embryos treated with 50 microM chloramphenicol, there was a significant reduction in the number of PGCs reaching genital ridges. In stimulated embryos, however, the number of PGCs was unchanged unless a higher concentration (500 microM) of chloramphenicol was used. From these results it is suggested that maternal mRNA translation during oocyte maturation plays a key role in development of PGCs.

  9. Implication of DNA demethylation and bivalent histone modification for selective gene regulation in mouse primordial germ cells.

    PubMed

    Mochizuki, Kentaro; Tachibana, Makoto; Saitou, Mitinori; Tokitake, Yuko; Matsui, Yasuhisa

    2012-01-01

    Primordial germ cells (PGCs) sequentially induce specific genes required for their development. We focused on epigenetic changes that regulate PGC-specific gene expression. mil-1, Blimp1, and Stella are preferentially expressed in PGCs, and their expression is upregulated during PGC differentiation. Here, we first determined DNA methylation status of mil-1, Blimp1, and Stella regulatory regions in epiblast and in PGCs, and found that they were hypomethylated in differentiating PGCs after E9.0, in which those genes were highly expressed. We used siRNA to inhibit a maintenance DNA methyltransferase, Dnmt1, in embryonic stem (ES) cells and found that the flanking regions of all three genes became hypomethylated and that expression of each gene increased 1.5- to 3-fold. In addition, we also found 1.5- to 5-fold increase of the PGC genes in the PGCLCs (PGC-like cells) induced form ES cells by knockdown of Dnmt1. We also obtained evidence showing that methylation of the regulatory region of mil-1 resulted in 2.5-fold decrease in expression in a reporter assay. Together, these results suggested that DNA demethylation does not play a major role on initial activation of the PGC genes in the nascent PGCs but contributed to enhancement of their expression in PGCs after E9.0. However, we also found that repression of representative somatic genes, Hoxa1 and Hoxb1, and a tissue-specific gene, Gfap, in PGCs was not dependent on DNA methylation; their flanking regions were hypomethylated, but their expression was not observed in PGCs at E13.5. Their promoter regions showed the bivalent histone modification in PGCs, that may be involved in repression of their expression. Our results indicated that epigenetic status of PGC genes and of somatic genes in PGCs were distinct, and suggested contribution of epigenetic mechanisms in regulation of the expression of a specific gene set in PGCs.

  10. Persistent Requirement and Alteration of the Key Targets of PRDM1 During Primordial Germ Cell Development in Mice.

    PubMed

    Yamashiro, Chika; Hirota, Takayuki; Kurimoto, Kazuki; Nakamura, Tomonori; Yabuta, Yukihiro; Nagaoka, So I; Ohta, Hiroshi; Yamamoto, Takuya; Saitou, Mitinori

    2016-01-01

    Primordial germ cells (PGCs) are the foundation of totipotency and vital for reproduction and heredity. PGCs in mice arise from the epiblast around Embryonic Day (E) 7.0, migrate through the hindgut endoderm, and colonize and proliferate in the embryonic gonads until around E13.5 prior to their differentiation either into prospermatogonia or oogonia. PRDM1, a transcriptional repressor, plays an essential role in PGC specification that includes robustly repressing a somatic mesodermal program. Using an inducible conditional knockout system, we show here that PRDM1 is critically required throughout PGC development. When Prdm1 was deleted in migrating PGCs at E9.5 or E10.5, or in male gonadal PGCs at E11.5, PGCs were eliminated by apoptosis from around E10.5, E11.5, or E13.5, respectively. When Prdm1 was deleted in female gonadal PGCs at E11.5, PGCs progressed into the first meiotic prophase in an apparently normal fashion, but the oogonia exhibited an aberrant pachytene phenotype, undergoing abrupt apoptosis from around E16.5. The escape of a fraction of PGCs (∼10%) from the Prdm1 deletion was sufficient to recover fairly normal germ cell pools, both in male and female adults. The key targets of PRDM1 in migrating and/or gonadal PGCs, including genes for development, apoptosis, and prospermatogonial differentiation, showed only a modest overlap with those upon PGC specification, and were enriched with histone H3 lysine 27 trimethylation (H3K27me3). Our findings provide critical insight into the mechanism for maintaining the transcriptional integrity of PGCs. © 2016 by the Society for the Study of Reproduction, Inc.

  11. Primordial germ cells: the first cell lineage or the last cells standing?

    PubMed Central

    Johnson, Andrew D.; Alberio, Ramiro

    2015-01-01

    Embryos of many animal models express germ line determinants that suppress transcription and mediate early germ line commitment, which occurs before the somatic cell lineages are established. However, not all animals segregate their germ line in this manner. The ‘last cell standing’ model describes primordial germ cell (PGC) development in axolotls, in which PGCs are maintained by an extracellular signalling niche, and germ line commitment occurs after gastrulation. Here, we propose that this ‘stochastic’ mode of PGC specification is conserved in vertebrates, including non-rodent mammals. We postulate that early germ line segregation liberates genetic regulatory networks for somatic development to evolve, and that it therefore emerged repeatedly in the animal kingdom in response to natural selection. PMID:26286941

  12. In vitro expansion of mouse primordial germ cell-like cells recapitulates an epigenetic blank slate.

    PubMed

    Ohta, Hiroshi; Kurimoto, Kazuki; Okamoto, Ikuhiro; Nakamura, Tomonori; Yabuta, Yukihiro; Miyauchi, Hidetaka; Yamamoto, Takuya; Okuno, Yukiko; Hagiwara, Masatoshi; Shirane, Kenjiro; Sasaki, Hiroyuki; Saitou, Mitinori

    2017-07-03

    The expansion of primordial germ cells (PGCs), the precursors for the oocytes and spermatozoa, is a key challenge in reproductive biology/medicine. Using a chemical screening exploiting PGC-like cells (PGCLCs) induced from mouse embryonic stem cells (ESCs), we here identify key signaling pathways critical for PGCLC proliferation. We show that the combinatorial application of Forskolin and Rolipram, which stimulate cAMP signaling via different mechanisms, expands PGCLCs up to ~50-fold in culture. The expanded PGCLCs maintain robust capacity for spermatogenesis, rescuing the fertility of infertile mice. Strikingly, during expansion, PGCLCs comprehensively erase their DNA methylome, including parental imprints, in a manner that precisely recapitulates genome-wide DNA demethylation in gonadal germ cells, while essentially maintaining their identity as sexually uncommitted PGCs, apparently through appropriate histone modifications. By establishing a paradigm for PGCLC expansion, our system reconstitutes the epigenetic "blank slate" of the germ line, an immediate precursory state for sexually dimorphic differentiation. © 2017 The Authors.

  13. Oct4 is required for primordial germ cell survival

    PubMed Central

    Kehler, James; Tolkunova, Elena; Koschorz, Birgit; Pesce, Maurizio; Gentile, Luca; Boiani, Michele; Lomelí, Hilda; Nagy, Andras; McLaughlin, K John; Schöler, Hans R; Tomilin, Alexey

    2004-01-01

    Previous studies have shown that Oct4 has an essential role in maintaining pluripotency of cells of the inner cell mass (ICM) and embryonic stem cells. However, Oct4 null homozygous embryos die around the time of implantation, thus precluding further analysis of gene function during development. We have used the conditional Cre/loxP gene targeting strategy to assess Oct4 function in primordial germ cells (PGCs). Loss of Oct4 function leads to apoptosis of PGCs rather than to differentiation into a trophectodermal lineage, as has been described for Oct4-deficient ICM cells. These new results suggest a previously unknown function of Oct4 in maintaining viability of mammalian germline. PMID:15486564

  14. [Retroperitoneal germ cell tumor].

    PubMed

    Borrell Palanca, A; García Garzón, J; Villamón Fort, R; Domenech Pérez, C; Martínez Lorente, A; Gunthner, S; García Sisamón, F

    1999-03-01

    We report a case of retroperitoneal extragonadal germ-cell tumor in an 17 years old patient who presented with aedema and pain in left inferior extremity asociated with hemopthysis caused by pulmonar metastasis, who was treated with chemotherapy and resection of residual mass and pulmonary nodes. Dyagnosis was stableshed by fine neadle aspiration biopsy of the wass. We comment on the difficult of stableshing differential dyagnosis between retroperitoneal extragonadal germ-cell tumor and metastasis of a testicular tumor. Dyagnosis is stableshed by the finding of a histologically malignant germ-cell tumor with normal testis. We considered physical examination and ecographyc exploration enough for a correct dyagnosis.

  15. A pilgrim's progress: Seeking meaning in primordial germ cell migration.

    PubMed

    Cantú, Andrea V; Laird, Diana J

    2017-07-18

    Comparative studies of primordial germ cell (PGC) development across organisms in many phyla reveal surprising diversity in the route of migration, timing and underlying molecular mechanisms, suggesting that the process of migration itself is conserved. However, beyond the perfunctory transport of cellular precursors to their later arising home of the gonads, does PGC migration serve a function? Here we propose that the process of migration plays an additional role in quality control, by eliminating PGCs incapable of completing migration as well as through mechanisms that favor PGCs capable of responding appropriately to migration cues. Focusing on PGCs in mice, we explore evidence for a selective capacity of migration, considering the tandem regulation of proliferation and migration, cell-intrinsic and extrinsic control, the potential for tumors derived from failed PGC migrants, the potential mechanisms by which migratory PGCs vary in their cellular behaviors, and corresponding effects on development. We discuss the implications of a selective role of PGC migration for in vitro gametogenesis. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  16. Exposure to endocrine disruptor induces transgenerational epigenetic deregulation of microRNAs in primordial germ cells.

    PubMed

    Brieño-Enríquez, Miguel A; García-López, Jesús; Cárdenas, David B; Guibert, Sylvain; Cleroux, Elouan; Děd, Lukas; Hourcade, Juan de Dios; Pěknicová, Jana; Weber, Michael; Del Mazo, Jesús

    2015-01-01

    In mammals, germ cell differentiation is initiated in the Primordial Germ Cells (PGCs) during fetal development. Prenatal exposure to environmental toxicants such as endocrine disruptors may alter PGC differentiation, development of the male germline and induce transgenerational epigenetic disorders. The anti-androgenic compound vinclozolin represents a paradigmatic example of molecule causing transgenerational effects on germ cells. We performed prenatal exposure to vinclozolin in mice and analyzed the phenotypic and molecular changes in three successive generations. A reduction in the number of embryonic PGCs and increased rate of apoptotic cells along with decrease of fertility rate in adult males were observed in F1 to F3 generations. Blimp1 is a crucial regulator of PGC differentiation. We show that prenatal exposure to vinclozolin deregulates specific microRNAs in PGCs, such as miR-23b and miR-21, inducing disequilibrium in the Lin28/let-7/Blimp1 pathway in three successive generations of males. As determined by global maps of cytosine methylation, we found no evidence for prominent changes in DNA methylation in PGCs or mature sperm. Our data suggest that embryonic exposure to environmental endocrine disruptors induces transgenerational epigenetic deregulation of expression of microRNAs affecting key regulatory pathways of germ cells differentiation.

  17. Germline development in amniotes: A paradigm shift in primordial germ cell specification

    PubMed Central

    2016-01-01

    In the field of germline development in amniote vertebrates, primordial germ cell (PGC) specification in birds and reptiles remains controversial. Avians are believed to adopt a predetermination or maternal specification mode of PGC formation, contrary to an inductive mode employed by mammals and, supposedly, reptiles. Here, we revisit and review some key aspects of PGC development that channelled the current subdivision, and challenge the position of birds and reptiles as well as the ‘binary’ evolutionary model of PGC development in vertebrates. We propose an alternative view on PGC specification where germ plasm plays a role in laying the foundation for the formation of PGC precursors (pPGC), but not necessarily of PGCs. Moreover, inductive mechanisms may be necessary for the transition from pPGCs to PGCs. Within this framework, the implementation of data from birds and reptiles could provide new insights on the evolution of PGC specification in amniotes. PMID:27273724

  18. BMP and Hh signaling affects primordial germ cell division in Drosophila.

    PubMed

    Sato, Takuya; Ogata, Jun; Niki, Yuzo

    2010-10-01

    The germline is segregated from the remainder of the soma during early embryonic development in metazoan species. In Drosophila, female primordial germ cells (PGCs) continue to proliferate during larval development, and become germline stem cells at the early pupal stage. To elucidate the roles of growth factors in larval PGC division, we examined expression patterns of a bone morphogenetic protein (BMP) growth factor, Decapentaplegic (Dpp), and Hedgehog (Hh), along with factors downstream of each, in the ovary during larval development. Dpp signaling appeared in the ovarian soma from early larval development, and was prominent in the terminal filament cells at late larval stage, whereas Hh appeared in the ovarian soma and PGCs from the third instar larval stage. The number of PGCs decreased when components of these signal transduction pathways were abrogated by RNAi in the PGCs, indicating that both Dpp and Hh signals directly regulate PGC proliferation. Experiments on the up- and down-regulation of Dpp and Hh with a tissue-specific Gal4 driver indicated that Dpp and Hh act as extrinsic and autocrine growth factors. Furthermore, heat-pulse experiments with hs-Gal4 showed that Dpp is active in PGC proliferation throughout larval development, whereas Hh has effects only during late larval development. In addition to Dpp, the reduction of Glass bottom boat (Gbb), another BMP molecule, caused a decrease in the number of PGCs and initiation of larval PGCs differentiation into cystocytes, indicating that Gbb functions to promote PGC division and repress differentiation.

  19. The migration and loss of human primordial germ stem cells from the hind gut epithelium towards the gonadal ridge.

    PubMed

    Mamsen, Linn Salto; Brøchner, Christian Beltoft; Byskov, Anne Grete; Møllgard, Kjeld

    2012-01-01

    Human primordial germ cells (PGCs) can be recognized in the yolk sac wall, from 3-4 weeks post conception (wpc), in the hind gut epithelium from week 4 and in the gonadal area from early week 5. The objective of this study was to map the migration route of PGCs and elucidate the role of the nervous system in this process. Sixteen human specimens, 5-14 wpc obtained from legal abortions were included. On serial paraffin sections, PGCs were detected immunohistochemically by expression of OCT4 and c-Kit, nerve fibers by β-III-tubulin and stem cell factor (SCF) as a possible chemoattractive cue for PGC migration. PGCs were present in the hind gut epithelium, in the mesenchyme of the dorsal mesentery and in the developing gonadal ridge of 4-6 wpc embryos, prior to connections between the enteric and the sympathetic nervous system. From 6 wpc onwards, the PGCs travelled along the developing nerve fibers from the wall of the hind gut via the dorsal mesentery to the midline of the dorsal wall and laterally into the gonads. Numerous PGCs were still present in the nervous system by 14 wpc. PGCs in 4-5 wpc embryos are suggested to leave the gut epithelium by EMT-like transition. SCF may facilitate further migration, but after establishment of connections between the enteric and sympathetic nervous systems. PGCs follow sympathetic nerve fibers towards the gonads. PGCs failing to exit the nerve branches at the gonadal site, may continue along the sympathetic trunk ending up in other organs where they may form germ cell tumors if not eliminated by apoptosis.

  20. 17β-Estradiol induces supernumerary primordial germ cells in embryos of the polychaete Platynereis dumerilii.

    PubMed

    Lidke, Anika K; Bannister, Stephanie; Löwer, Andreas M; Apel, David M; Podleschny, Martina; Kollmann, Martin; Ackermann, Christian F; García-Alonso, Javier; Raible, Florian; Rebscher, Nicole

    2014-01-15

    In the polychaete Platynereis dumerilii exactly four primordial germ cells (PGCs) arise in early development and are subject to a transient mitotic arrest until the animals enter gametogenesis. In order to unravel the mechanisms controlling the number of PGCs in Platynereis, we tested whether the steroid 17β-estradiol (E2) is able to induce PGC proliferation, as it had been described in other species. Our data provide strong support for such a mechanism, showing that E2 significantly increases the occurrence of larvae with supernumerary PGCs in Platynereis in a dose dependent manner. E2 responsiveness is restricted to early developmental stages, when the PGCs are specified. During these stages, embryos exhibit high expression levels of the estradiol receptor (ER). The ER transcript localizes to the yolk-free cytoplasm of unfertilized eggs and segregates into the micromeres during cleavage stages. Nuclear ER protein is found asymmetrically distributed between daughter cells. Neither transcript nor protein is detectable in PGCs at larval stages. Addition of the specific estradiol receptor inhibitor ICI-182,780 (ICI) abolishes the proliferative effect of E2, suggesting that it is mediated by ER signaling. Our study reports for the first time an ER mediated proliferative effect of E2 on PGCs in an invertebrate organism. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. [Testicular germ cell tumors].

    PubMed

    Dourthe, L M; Ouachet, M; Fizazi, K; Droz, J P

    1998-09-01

    Testicle germ cells tumors are the most common young men neoplasm. The incidence is maximal in Scandinavian countries. Cryptorchidism is a predisposing factor. Diagnosis is clinic, first treatment is radical orchidectomy by inguinal incision, after study of tumor markers. Histology shows seminoma or non seminomatous tumor. Carcinoma in situ is the precursor of invasive germ cell tumors. Germ cell tumors have no p53 mutation, and have isochrome of the short arm of chromosome 12 as a specific marker. With the results of histological, biochemical and radiographic evaluation, patient are classified as follows: good, intermediate and poor risk prognosis. Standard treatment of stage I seminoma is prophylactic irradiation. Stage II with less than 3 cm lymph node too. Other situations need a cisplatin based chemotherapy. In case of metastatic residuals masses more than 3 cm, surgery need to be discussed. Stage I non seminomatous germ cell tumors are treated by retroperitoneal lymphadenectomy, by surveillance or by two cycles of adjuvant chemotherapy with cisplatin, etoposide and bleomycin (BEP). Standard treatment of good prognosis stage II and III is three cycles of BEP, four for poor prognosis. Residual mass need surgery, adjuvant chemotherapy is necessary in presence of viable germ cell. Standard treatment for relapses is chemotherapy with cisplatin, ifosfamide and vinblastine with a 30% remission rate. The place of high dose chemotherapy with autologous stem cell transplantation is not yet standardised. New drugs, as paclitaxel, are under studies.

  2. Obtaining chicken primordial germ cells used for gene transfer: in vitro and in vivo results.

    PubMed

    Chojnacka-Puchta, Luiza; Sawicka, Dorota; Lakota, Paweł; Plucienniczak, Grazyna; Bednarczyk, Marek; Plucienniczak, Andrzej

    2015-11-01

    Recently, several attempts have been made to create a generation of transgenic chickens via chimeric intermediates produced by primordial germ cells (PGCs) transfer. This study aimed to compare the influences of different chicken PGCs isolated from circulating blood (bPGCs) or gonads (gPGCs), purification (ACK, Percoll or trypsin) and transfection methods (electroporation or lipofection) on the expression of transgenes in vitro and the migration of modified donor cells to the recipient gonads. The highest average frequency of pEGFP-N1 plasmid-transfected bPGCs (75.8%) was achieved with Percoll density gradient centrifugation and electroporation. After ammonium chloride-potassium (ACK) treatment and lipofection, in vitro transgene expression was only detected in 35.2% of bPGCs. Chimeric chickens were produced from these purified, transfected and cultured cells, and the transgene was detected in the gonads of 44 and 42% of the recipient embryos that had been injected with bPGCs and gPGCs, respectively. These data confirmed that the combination of PGC purification via Percoll centrifugation and electroporation was an effective method for producing transgenic chickens. Subsequently, we used this method with expression vectors for gene hIFNα 2a/hepatitis B virus surface antigen (HBsAg) under the control of the ovalbumin promoter to generate G0 transgenic chickens. Consequently, we observed that 4.9% of the hens and 3.5% of the roosters carried the hIFNα 2a gene, whereas 16.7% of the hens and 2.4% of the roosters carried the HBsAg gene, thus undisputedly confirming the exceptional effectiveness of the applied methods.

  3. A perspective on the evolution of germ-cell development and germinal mosaics of deleterious mutations.

    PubMed

    Woodruff, Ronny C; Balinski, Michael A; Bouzat, Juan L

    2015-10-01

    In many animals a small number of primordial germ cells (PGCs) are set aside early in development, mitosis and mitochondrial DNA syntheses are arrested, transcription is stopped or reduced, and the PGCs migrate later to the emerging gonads and become germ cells. What could be the evolutionary advantage of sequestering non-dividing PGCs early in development? A commonly cited advantage is a reduction in the number of new deleterious mutations that would occur if there were additional divisions in PGCs early in development. We would like to add to this advantage the fact that these additional mutations in PGCs give rise to germinal mosaics (i.e., premeiotic clusters of mutation) in multiple progeny of the same individual, thus having a larger detrimental effect on the evolutionary fitness of their carriers. Here, we reviewed published studies providing evidence that germinal mosaics of deleterious mutant alleles are not rare, occur for all types of genetic damage, and have been observed in all tested organisms and in nature. We propose the hypothesis that PGC sequestration during early animal development may have evolved in part in response to selection for preventing the occurrence of premeiotic clusters of deleterious mutant alleles, and describe a series of predictions that would allow the assessment of the potential role of germinal mosaics on the evolution of PGC sequestration.

  4. The migrations of Drosophila muscle founders and primordial germ cells are interdependent.

    PubMed

    Stepanik, Vincent; Dunipace, Leslie; Bae, Young-Kyung; Macabenta, Frank; Sun, Jingjing; Trisnadi, Nathanie; Stathopoulos, Angelike

    2016-09-01

    Caudal visceral mesoderm (CVM) cells migrate from posterior to anterior of the Drosophila embryo as two bilateral streams of cells to support the specification of longitudinal muscles along the midgut. To accomplish this long-distance migration, CVM cells receive input from their environment, but little is known about how this collective cell migration is regulated. In a screen we found that wunen mutants exhibit CVM cell migration defects. Wunens are lipid phosphate phosphatases known to regulate the directional migration of primordial germ cells (PGCs). PGC and CVM cell types interact while PGCs are en route to the somatic gonadal mesoderm, and previous studies have shown that CVM impacts PGC migration. In turn, we found here that CVM cells exhibit an affinity for PGCs, localizing to the position of PGCs whether mislocalized or trapped in the endoderm. In the absence of PGCs, CVM cells exhibit subtle changes, including more cohesive movement of the migrating collective, and an increased number of longitudinal muscles is found at anterior sections of the larval midgut. These data demonstrate that PGC and CVM cell migrations are interdependent and suggest that distinct migrating cell types can coordinately influence each other to promote effective cell migration during development. © 2016. Published by The Company of Biologists Ltd.

  5. Identification of genes specific to mouse primordial germ cells through dynamic global gene expression.

    PubMed

    Sabour, Davood; Araúzo-Bravo, Marcos J; Hübner, Karin; Ko, Kinarm; Greber, Boris; Gentile, Luca; Stehling, Martin; Schöler, Hans R

    2011-01-01

    Molecular mechanisms underlying the commitment of cells to the germ cell lineage during mammalian embryogenesis remain poorly understood due to the limited availability of cellular materials to conduct in vitro analyses. Although primordial germ cells (PGCs)--precursors to germ cells--have been generated from embryonic stem cells (ESCs)--pluripotent stem cells derived from the inner cell mass of the blastocyst of the early embryo in vitro-the simultaneous expression of cell surface receptors and transcription factors complicates the detection of PGCs. To date, only a few genes that mark the onset of germ cell commitment in the epiblast--the outer layer of cells of the embryo--including tissue non-specific alkaline phosphatase (TNAP), Blimp1, Stella and Fragilis--have been used with some success to detect PGC formation in in vitro model systems. Here, we identified 11 genes (three of which are novel) that are specifically expressed in male and female fetal germ cells, both in vivo and in vitro, but are not expressed in ESCs. Expression of these genes allows us to distinguish committed germ cells from undifferentiated pluripotent cell populations, a prerequisite for the successful derivation of germ cells and gametes in vitro.

  6. Primordial germ cell biology at the beginning of the XXI century.

    PubMed

    De Felici, Massimo

    2009-01-01

    At the XIV Workshop on the Development and Function of the Reproductive Organs held at the Congress Centre of the University of Rome Tor Vergata, Monteporzio Catone, Rome, Italy, the introduction to the first session entitled Mammalian primordial germ cells dedicated to the memory of Anne McLaren, was the occasion for a concise review of the state of art of research on the biology of primordial germ cells (PGCs). This great, unforgettable scientist, who died in a car accident in July 2007, dedicated most of her studies to this field over the last 25 years. Topics briefly reviewed in this Meeting Report are: 1) how the germ line is determined; 2) what are the mechanisms underlying PGC migration; 3) to what extent PGC survival, proliferation and differentiation are cell autonomous or environmentally controlled processes and 4) how the potential for totipotency is retained in PGCs.

  7. Cryopreservation of primordial germ cells by rapid cooling of whole zebrafish (Danio rerio) embryos.

    PubMed

    Higaki, Shogo; Mochizuki, Kentaro; Akashi, Yuichiro; Yamaha, Etsuro; Katagiri, Seiji; Takahashi, Yoshiyuki

    2010-04-01

    The feasibility of cryopreservation of zebrafish (Danio rerio) primordial germ cells (PGCs) by rapid cooling (i.e., vitrification) of dechorionated whole embryos at the 14- to 20-somite stage was investigated. Initially, we examined the glass-forming properties and embryo toxicities of six cryoprotectants: methanol (MeOH), ethylene glycol (EG), glycerol (GC), dimethyl sulfoxide (DMSO), propylene glycol (PG) and 1,3-butylene glycol (1,3-BG). According to the results of glass-forming and embryo toxicity tests, pretreatment solution (PS) containing 2 or 3 M cryoprotectant and vitrification solution (VS) containing 5 M cryoprotectant and 0.5 M sucrose were prepared using each cryoprotectant. Dechorionated embryos, the PGCs of which were visualized by injection of green fluorescence protein-nos1 3'UTR mRNA, were cooled rapidly by plunging into liquid nitrogen after serial exposure to PS and VS. All embryos cooled with MeOH, PG and 1,3-BG showed ice formation during cooling, and few embryos had live PGCs after warming. Most embryos cooled with GC did not show ice formation; however, few embryos had live PGCs. All embryos cooled with EG and most embryos cooled with DMSO had live PGCs when the embryos did not show ice formation during cooling. Based on the number of live PGCs in fresh embryos, the maximum survival rates of PGCs recovered from embryos cooled with EG and DMSO were estimated to be about 40 and 20%, respectively. The present study indicates that rapid cooling of dechorionated whole embryos, especially using EG-based solutions, could be utilized as a simple and promising tool for cryopreservation of PGCs.

  8. Dnd Is a Critical Specifier of Primordial Germ Cells in the Medaka Fish.

    PubMed

    Hong, Ni; Li, Mingyou; Yuan, Yongming; Wang, Tiansu; Yi, Meisheng; Xu, Hongyan; Zeng, Huaqiang; Song, Jianxing; Hong, Yunhan

    2016-03-08

    Primordial germ cell (PGC) specification occurs early in development. PGC specifiers have been identified in Drosophila, mouse, and human but remained elusive in most animals. Here we identify the RNA-binding protein Dnd as a critical PGC specifier in the medaka fish (Oryzias latipes). Dnd depletion specifically abolished PGCs, and its overexpression boosted PGCs. We established a single-cell culture procedure enabling lineage tracing in vitro. We show that individual blastomeres from cleavage embryos at the 32- and 64-cell stages are capable of PGC production in culture. Importantly, Dnd overexpression increases PGCs via increasing PGC precursors. Strikingly, dnd RNA forms prominent particles that segregate asymmetrically. Dnd concentrates in germ plasm and stabilizes germ plasm RNA. Therefore, Dnd is a critical specifier of fish PGCs and utilizes particle partition as a previously unidentified mechanism for asymmetric segregation. These findings offer insights into PGC specification and manipulation in medaka as a lower vertebrate model. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Ovarian Germ Cell Tumors Treatment

    MedlinePlus

    ... Tube, & Primary Peritoneal Cancer Screening Research Ovarian Germ Cell Tumors Treatment (PDQ®)–Patient Version General Information About Ovarian Germ Cell Tumors Go to Health Professional Version Key Points ...

  10. Genome-Wide Profiling of Pluripotent Cells Reveals a Unique Molecular Signature of Human Embryonic Germ Cells

    PubMed Central

    Pashai, Nikta; Hao, Haiping; All, Angelo; Gupta, Siddharth; Chaerkady, Raghothama; De Los Angeles, Alejandro; Gearhart, John D.; Kerr, Candace L.

    2012-01-01

    Human embryonic germ cells (EGCs) provide a powerful model for identifying molecules involved in the pluripotent state when compared to their progenitors, primordial germ cells (PGCs), and other pluripotent stem cells. Microarray and Principal Component Analysis (PCA) reveals for the first time that human EGCs possess a transcription profile distinct from PGCs and other pluripotent stem cells. Validation with qRT-PCR confirms that human EGCs and PGCs express many pluripotency-associated genes but with quantifiable differences compared to pluripotent embryonic stem cells (ESCs), induced pluripotent stem cells (IPSCs), and embryonal carcinoma cells (ECCs). Analyses also identified a number of target genes that may be potentially associated with their unique pluripotent states. These include IPO7, MED7, RBM26, HSPD1, and KRAS which were upregulated in EGCs along with other pluripotent stem cells when compared to PGCs. Other potential target genes were also found which may contribute toward a primed ESC-like state. These genes were exclusively up-regulated in ESCs, IPSCs and ECCs including PARP1, CCNE1, CDK6, AURKA, MAD2L1, CCNG1, and CCNB1 which are involved in cell cycle regulation, cellular metabolism and DNA repair and replication. Gene classification analysis also confirmed that the distinguishing feature of EGCs compared to ESCs, ECCs, and IPSCs lies primarily in their genetic contribution to cellular metabolism, cell cycle, and cell adhesion. In contrast, several genes were found upregulated in PGCs which may help distinguish their unipotent state including HBA1, DMRT1, SPANXA1, and EHD2. Together, these findings provide the first glimpse into a unique genomic signature of human germ cells and pluripotent stem cells and provide genes potentially involved in defining different states of germ-line pluripotency. PMID:22737227

  11. RNA Granules in Germ Cells

    PubMed Central

    Voronina, Ekaterina; Seydoux, Geraldine; Sassone-Corsi, Paolo; Nagamori, Ippei

    2011-01-01

    Germ granules” are cytoplasmic, nonmembrane-bound organelles unique to germline. Germ granules share components with the P bodies and stress granules of somatic cells, but also contain proteins and RNAs uniquely required for germ cell development. In this review, we focus on recent advances in our understanding of germ granule assembly, dynamics, and function. One hypothesis is that germ granules operate as hubs for the posttranscriptional control of gene expression, a function at the core of the germ cell differentiation program. PMID:21768607

  12. Expression of vasa and nanos3 during primordial germ cell formation and migration in Atlantic cod (Gadus morhua L.).

    PubMed

    Presslauer, C; Nagasawa, K; Fernandes, J M O; Babiak, I

    2012-10-01

    Primordial germ cells (PGCs), progenitors of gametes, are specified very early in embryonic development and undergo an active migration to the site where the future gonads will form. While the developmental pattern of PGCs during embryogenesis has been documented in few model teleost fishes, there is currently no information available for any representative of Superorder Paracanthopterygii. This includes Atlantic cod (Gadus morhua), which is a historically important food fish in both fisheries and aquaculture industries. In the present study, we cloned and characterized vasa and nanos3 and used them as germ cell markers in Atlantic cod. Sequencing results showed prospective vasa and nanos3 mRNA contained the domains used to describe their respective protein family. Furthermore, phylogenetic analysis using the amino acid sequence placed Atlantic cod Vasa distinct from representatives of three other taxonomic Superorders. Atlantic cod Nanos3 was placed with other homologues from the Nanos3 subfamily. Expression of both genes was detected from the first cleavage division; both were specifically expressed in Atlantic cod PGCs from the 32-cell stage. While nanos3 expression ceased during early somitogenesis, vasa was strongly expressed throughout embryonic development. Using vasa as a marker, we described the Atlantic cod PGC migration pattern. We demonstrated that Atlantic cod PGCs migrate ventral to the trunk mesoderm. With the exception of Pacific herring (Clupea pallasii), PGCs in other described teleost fishes migrate lateral to the trunk. The results from this study are the first step toward understanding germ line formation in Atlantic cod.

  13. RNA-binding protein TIAR is essential for primordial germ cell development.

    PubMed

    Beck, A R; Miller, I J; Anderson, P; Streuli, M

    1998-03-03

    Primordial germ cells (PGCs) give rise to both eggs and sperm via complex maturational processes that require both cell migration and proliferation. However, little is known about the genes controlling gamete formation during the early stages of PGC development. Although several mutations are known to severely reduce the number of PGCs reaching and populating the genital ridges, the molecular identity of only two of these genes is known: the c-kit receptor protein tyrosine kinase and the c-kit ligand (the steel factor). Herein, we report that mutant mice lacking TIAR, an RNA recognition motif/ribonucleoprotein-type RNA-binding protein highly expressed in PGCs, fail to develop spermatogonia or oogonia. This developmental defect is a consequence of reduced survival of PGCs that migrate to the genital ridge around embryonic day 11.5 (E11.5). The numbers of PGCs populating the genital ridge in TIAR-deficient embryos are severely reduced compared to wild-type embryos by E11.5 and in the mutants PGCs are completely absent at E13.5. Furthermore, TIAR-deficient embryonic stem cells do not proliferate in the absence of exogenous leukemia inhibitory factor in an in vitro methylcellulose culture assay, supporting a role for TIAR in regulating cell proliferation. Because the development of PGCs relies on the action of several growth factors, these results are consistent with a role for TIAR in the expression of a survival factor or survival factor receptor that is essential for PGC development. TIAR-deficient mice thus provide a model system to study molecular mechanisms of PGC development and possibly the basis for some forms of idiopathic infertility.

  14. Germ cell formation from embryonic stem cells and the use of somatic cell nuclei in oocytes.

    PubMed

    Pelosi, Emanuele; Forabosco, Antonino; Schlessinger, David

    2011-03-01

    Embryonic stem cells (ESCs) have remarkable properties of pluripotency and self-renewal, along with the retention of chromosomal integrity. Germ cells function as a kind of "transgenerational stem cells," transmitting genetic information from one generation to the next. The formation of putative primordial germ cells (PGCs) and germ cells from mouse and human ESCs (hESCs) has, in fact, been shown, and the apparent derivation of functional mouse male gametes has also been described. Additionally, investigators have successfully reprogrammed somatic nuclei into a pluripotent state by inserting them into ESCs or oocytes. This would enable the generation of ESCs genetically identical to the somatic cell donor and their use in cell therapy. However, these methodologies are still inefficient and their mechanisms poorly understood. Until full comprehension of these processes is obtained, clinical applications remain remote. Nevertheless, they represent promising tools in the future, enhancing methods of therapeutic cloning and infertility treatment.

  15. Cloning and characterization of a vasa-like gene in rainbow trout and its expression in the germ cell lineage.

    PubMed

    Yoshizaki, G; Sakatani, S; Tominaga, H; Takeuchi, T

    2000-04-01

    The origin of germ cells and the molecular mechanisms of primordial germ cell (PGC) determination in teleosts are unclear. Vasa is a member of the DEAD protein family and plays an indispensable role in germ cell determination in Drosophila and Xenopus species. In this study, we isolated and characterized a rainbow trout vasa cDNA as a first step towards understanding the molecular mechanisms of PGC determination and development and to develop a molecular marker to identify the PGCs in rainbow trout. Cloning of vasa cDNA was performed by degenerate- and RACE-PCR. The predicted amino acid sequence of rainbow trout Vasa contained eight consensus sequences for the DEAD protein family and five arginine-glycine-glycine repeats, a common character of known Vasa homologues. Overall amino acid similarity to the Vasa of Drosophila was 79.2%. Whole-mount in situ hybridization of eyed stage embryos (eighty somite stage) revealed that signals were localized to the putative PGCs. In adult rainbow trout tissues, both ovaries and testes contained large amounts of vasa gene transcripts. A reverse transcription-polymerase chain reaction analysis of unfertilized eggs proved that trout vasa is a maternal factor. Although we have not determined whether rainbow trout vasa functions as a germ cell determinant, its limited expression in the germ cell lineage proved that rainbow trout vasa can be used as a marker molecule for PGCs. This marker will make it possible to identify the PGCs or presumptive PGCs in early trout embryos whose germ cells can not be distinguished by morphological characteristics.

  16. Cryopreservation of chicken primordial germ cells by vitrification and slow freezing: A comparative study.

    PubMed

    Tonus, C; Connan, D; Waroux, O; Vandenhove, B; Wayet, J; Gillet, L; Desmecht, D; Antoine, N; Ectors, F J; Grobet, L

    2017-01-15

    In the present study, we compare a classical slow freezing (SLF) method and an aseptic vitrification (Vitrif) technique to cryopreserve a stable primordial germ cell (PGCs) line issued from the Ardennaise chicken breed. Viability immediately after warming was close to 80% and did not differ between the two cryopreservation methods. Proliferation tended to be slower for both cryopreservation methods compared with controls, but the difference was significant only for Vitrif. No difference was found between the two methods after flow cytometry analysis of stage-specific embryonic antigen-1 expression and reverse transcription-polymerase chain reaction on several factors related to PGC phenotype. After 1 week in culture, all cryopreserved cells reached controls' main morphologic and expanding (viability/proliferation) features. However, SLF generated more unwanted cells clusters than Vitrif. After injection of the PGCs into recipient embryos, vitrified PGCs reported a clear, yet not significant, tendency to colonize the gonad at a higher rate than slow frozen PGCs. SLF in cryovials remains simple, inexpensive, and less technically demanding than Vitrif. Nevertheless, the intrinsic advantages of our aseptic Vitrif method and the present study suggest that this should be considered as safer than classical SLF for cryopreserving chicken PGCs. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. In vitro generation and characterization of chicken long-term germ cells from different embryonic origins.

    PubMed

    Raucci, Franca; Fuet, Aurelie; Pain, Bertrand

    2015-09-15

    Primordial germ cells (PGCs) are the precursors of differentiated germ cells. Located in the epiblast of a stage X (EG&K) embryo, the PGCs translocate anteriorly to the germinal crescent and migrate, within 48 to 56 hours of development, through the blood vascular system to the germinal ridges where they become the gonadal germ cells (GGCs). We aim to generate, compare, and determine the basic characters of the in vitro long-term cultured PGCs derived from (1) the chicken blastodermal cells (at stages IX-XII); (2) the chicken blood of a 2-day old embryo (stages 14-17 Hamburger Hamilton [HH]); and (3) the long-term cultured gonocytes taken from male gonads of a 5- to 6-day-old embryo (stages 29-30 HH). In presence of fibroblast growth factor, chicken blastodermal cells are able to long-term proliferate and generate small, round, alkaline phosphatase-positive cell clusters. Molecular characterization shows that these selected and amplified clusters show a PGC-like cell profile, as they express cPOUV (a pluripotent-associated marker), NR6A1/GCNF and DDX4/CVH (germ cell-specific genes). Both chicken PGCs and GGCs, obtained from embryonic blood and gonads, at 14 to 17 HH and 29 to 30 HH, respectively, generate long-term germ cell cultures and positively react in vitro to periodic acid-Schiff. Immunochemical analyses reveal that these cell lines are specifically recognized by anti-SSEA-1, anti-EMA-1, anti-CVH, anti-β1-integrin, and anti-CEACAM antibodies. The presence of surrounding cells may suggest a stronger dependency toward the niche process for the GGCs. The reactivity of chicken embryonic germ cells obtained from the two different sources to the specific markers used in this study was not altered through the culture. In conclusion, the morphologic analysis specific for chicken PGCs and GGCs will further contribute to quick and reliable characterization of long-term cultured in vitro chicken germ cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Trans-generational epigenetic regulation of C. elegans primordial germ cells

    PubMed Central

    2010-01-01

    Background The processes through which the germline maintains its continuity across generations has long been the focus of biological research. Recent studies have suggested that germline continuity can involve epigenetic regulation, including regulation of histone modifications. However, it is not clear how histone modifications generated in one generation can influence the transcription program and development of germ cells of the next. Results We show that the histone H3K36 methyltransferase maternal effect sterile (MES)-4 is an epigenetic modifier that prevents aberrant transcription activity in Caenorhabditis elegans primordial germ cells (PGCs). In mes-4 mutant PGCs, RNA Pol II activation is abnormally regulated and the PGCs degenerate. Genetic and genomewide analyses of MES-4-mediated H3K36 methylation suggest that MES-4 activity can operate independently of ongoing transcription, and may be predominantly responsible for maintenance methylation of H3K36 in germline-expressed loci. Conclusions Our data suggest a model in which MES-4 helps to maintain an 'epigenetic memory' of transcription that occurred in germ cells of previous generations, and that MES-4 and its epigenetic product are essential for normal germ cell development. PMID:20704745

  19. The Formation and Migration of Primordial Germ Cells in Mouse and Man.

    PubMed

    De Felici, Massimo

    In most multicellular organisms, including mammals, germ cells are at the origin of new organisms and ensure the continuation of the genetic and epigenetic information across the generations.In the mammalian germ line, the primordial germ cells (PGCs) are the precursors of the primary oocytes and prospermatogonia of fetal ovaries and testes, respectively. In mammals such as the primates, in which the formation of the primary oocytes is largely asynchronous and occurs during a relatively long period, PGCs after the arrival into the XX gonadal ridges are termed oogonia which then become primary oocytes when entering into meiotic prophase I. In the fetal testes, germ cells derived from the PGCs after gonad colonization are termed prospermatogonia or gonocytes.One of the most fascinating aspect of the mammalian germline development is that it is probably the first cell lineage to be established in the embryo by epigenetic mechanisms and that these inductive events happen in extraembryonic tissues much earlier that gonad develop inside the embryo proper. Moreover, such events prepare the germ cells for totipotency through genetic and epigenetic regulations of their genome function. How this occurs remained a mystery until short time ago.In this chapter, I will report and discuss the most recent advances in the cellular and molecular mechanisms underlying the formation in extraembryonic tissues and migration of PGCs toward the gonadal ridges made primarily by studies carried out in the mouse with some perspective in the human. Established concepts about these processes will be only summarized when necessary since they are widely described and discussed in many excellent reviews; most of them are cited in the text below.

  20. Development of fertile mouse oocytes from mitotic germ cells in vitro.

    PubMed

    Morohaku, Kanako; Hirao, Yuji; Obata, Yayoi

    2017-09-01

    Mammalian fetal ovaries contain numerous primordial germ cells (PGCs), although few mature oocytes are obtained from females, owing to apoptosis and follicle atresia. The regulatory mechanisms underlying oogenesis/folliculogenesis remain unknown. Development of methods for obtaining mature oocytes from PGCs in fetal ovaries in vitro could contribute to clarifying these mechanisms. The failure of follicle assembly has been found to be the most challenging aspect in conventional culture conditions. Recently, we established novel culture conditions that enable successful follicle assembly, sustaining interactions between the oocyte and somatic cells, and, in turn, promoting oocyte growth and maturation. Mature oocytes were differentiated from PGCs after a 1-month culture period. A hundred mouse offspring were obtained from approximately a thousand mature oocytes, indicating that oocytes that were differentiated from PGCs in vitro acquired totipotency after fertilization. Here we provide a detailed protocol for using this in vitro system. This in vitro system will potentially provide a novel platform for studying oogenesis and preservation of female germ cells.

  1. Visualization of primordial germ cells in the fertilized pelagic eggs of the barfin flounder Verasper moseri.

    PubMed

    Goto, Rie; Saito, Taiju; Kawakami, Yutaka; Kitauchi, Tomoe; Takagi, Misae; Todo, Takashi; Arai, Katsutoshi; Yamaha, Etsuro

    2015-01-01

    Primordial germ cells (PGCs) appear during early embryogenesis and differentiate into gametes through oogenesis or spermatogenesis. Teleost PGCs can be visualized by injecting RNA transcribed from the fusion product of a fluorescent protein gene attached to the 3' untranslated region (3'UTR) of zebrafish nanos3 (zf-nos3). Although this method has been widely applied to teleost PGCs, the visualization of PGCs in pelagic species that have eggs with a hard chorion is more problematic due to the technical difficulty of microinjection into their eggs. In this study, we developed a reliable method for microinjection of fertilized eggs in a pelagic species, the barfin flounder. Using a microneedle with a constriction "brake", we were able to introduce gfp-nos3 3'UTR mRNA into embryos and to determine the origin and migration route of PGCs. We also isolated the barfin flounder nos3 (bf-nos3) gene to compare its 3'UTR sequence with that of zebrafish. The 3'UTR of the bf-nos3 sequence was longer than that of zf-nos3. However, PGCs were also visualized after injection of gfp-bf-nos3 3'UTR mRNA both in zebrafish and barfin flounder. These results suggest that the function of nos3 is conserved between these species regardless of the sequence differences. The method developed here for labeling PGCs with gfp-nos3 mRNA will provide a means to study PGC development in the embryos of a wide range of marine fish species.

  2. Fatty acid degradation plays an essential role in proliferation of mouse female primordial germ cells via the p53-dependent cell cycle regulation.

    PubMed

    Teng, Hui; Sui, Xuesong; Zhou, Cheng; Shen, Cong; Yang, Ye; Zhang, Pang; Guo, Xuejiang; Huo, Ran

    2016-01-01

    Primordial germ cells (PGCs) are embryonic founders of germ cells that ultimately differentiate into oocytes and spermatogonia. Embryonic proliferation of PGCs starting from E11.5 ensures the presence of germ cells in adulthood, especially in female mammals whose total number of oocytes declines after this initial proliferation period. To better understand mechanisms underlying PGC proliferation in female mice, we constructed a proteome profile of female mouse gonads at E11.5. Subsequent KEGG pathway analysis of the 3,662 proteins profiled showed significant enrichment of pathways involved in fatty acid degradation. Further, the number of PGCs found in in vitro cultured fetal gonads significantly decreased with application of etomoxir, an inhibitor of the key rate-limiting enzyme of fatty acid degradation carnitine acyltransferase I (CPT1). Decrease in PGCs was further determined to be the result of reduced proliferation rather than apoptosis. The inhibition of fatty acid degradation by etomoxir has the potential to activate the Ca(2+)/CamKII/5'-adenosine monophosphate-activated protein kinase (AMPK) pathway; while as an upstream activator, activated AMPK can function as activator of p53 to induce cell cycle arrest. Thus, we detected the expressional level of AMPK, phosphorylated AMPK (P-AMPK), phosphorylated p53 (P-p53) and cyclin-dependent kinase inhibitor 1 (p21) by Western blots, the results showed increased expression of them after treatment with etomoxir, suggested the activation of p53 pathway was the reason for reduced proliferation of PGCs. Finally, the involvement of p53-dependent G1 cell cycle arrest in defective proliferation of PGCs was verified by rescue experiments. Our results demonstrate that fatty acid degradation plays an important role in proliferation of female PGCs via the p53-dependent cell cycle regulation.

  3. Fatty acid degradation plays an essential role in proliferation of mouse female primordial germ cells via the p53-dependent cell cycle regulation

    PubMed Central

    Teng, Hui; Sui, Xuesong; Zhou, Cheng; Shen, Cong; Yang, Ye; Zhang, Pang; Guo, Xuejiang; Huo, Ran

    2016-01-01

    ABSTRACT Primordial germ cells (PGCs) are embryonic founders of germ cells that ultimately differentiate into oocytes and spermatogonia. Embryonic proliferation of PGCs starting from E11.5 ensures the presence of germ cells in adulthood, especially in female mammals whose total number of oocytes declines after this initial proliferation period. To better understand mechanisms underlying PGC proliferation in female mice, we constructed a proteome profile of female mouse gonads at E11.5. Subsequent KEGG pathway analysis of the 3,662 proteins profiled showed significant enrichment of pathways involved in fatty acid degradation. Further, the number of PGCs found in in vitro cultured fetal gonads significantly decreased with application of etomoxir, an inhibitor of the key rate-limiting enzyme of fatty acid degradation carnitine acyltransferase I (CPT1). Decrease in PGCs was further determined to be the result of reduced proliferation rather than apoptosis. The inhibition of fatty acid degradation by etomoxir has the potential to activate the Ca2+/CamKII/5′-adenosine monophosphate-activated protein kinase (AMPK) pathway; while as an upstream activator, activated AMPK can function as activator of p53 to induce cell cycle arrest. Thus, we detected the expressional level of AMPK, phosphorylated AMPK (P-AMPK), phosphorylated p53 (P-p53) and cyclin-dependent kinase inhibitor 1 (p21) by Western blots, the results showed increased expression of them after treatment with etomoxir, suggested the activation of p53 pathway was the reason for reduced proliferation of PGCs. Finally, the involvement of p53-dependent G1 cell cycle arrest in defective proliferation of PGCs was verified by rescue experiments. Our results demonstrate that fatty acid degradation plays an important role in proliferation of female PGCs via the p53-dependent cell cycle regulation. PMID:26716399

  4. GalNAc moieties in O-linked oligosaccharides of the primordial germ cells of Xenopus embryos.

    PubMed

    Alonso, Edurne; Sáez, Francisco José; Madrid, Juan Francisco; Hernández, Francisco

    2002-04-01

    Glycoconjugates could play a role in cell adhesion and migration mechanisms, including the locomotive movements of the primordial germ cells (PGCs) during the development of the embryo. In the present work, we have studied by lectin histochemistry the presence of N-acetylgalactosamine (GalNAc) in the glycans of the Xenopus PGCs, as a first approach to identifying their glycoconjugates which could be involved in the migration mechanism. The PGCs were negative for three of the GalNAc-binding lectins employed (from soybean, SBA; from lima bean, LBA; and from snail, HPA). However, when sialic acid (NeuAc) was previously removed by acid hydrolysis, SBA and HPA, but not LBA, labeled the PGCs, except if the staining was combined with the beta-elimination procedure. This suggests the presence of GalNAc alpha(1,3)-linked to galactose (Gal) in O-linked oligosaccharides, in a subterminal position to NeuAc. As the PGCs were always negative for LBA, the absence of fucose alpha(1,2)-linked to subterminal Gal is suggested. With the lectin from horse gram (DBA), the PGCs were stained, although beta-elimination turned the cells negative and acid hydrolysis increased the labeling, suggesting that GalNAc(alpha)(1,3)GalNAc was in O-linked glycans in terminal and subterminal to NeuAc position.

  5. Endocrine disrupters, microRNAs, and primordial germ cells: a dangerous cocktail.

    PubMed

    Brieño-Enríquez, Miguel Angel; Larriba, Eduardo; Del Mazo, Jesús

    2016-09-15

    Endocrine-disrupting chemicals (EDCs) are environmental pollutants that may change the homeostasis of the endocrine system, altering the differentiation of germ cells with consequences for reproduction. In mammals, germ cell differentiation begins with primordial germ cells (PGCs) during embryogenesis. Primordial germ cell development and gametogenesis are genetically regulated processes, in which the posttranscriptional gene regulation could be mediated by small noncoding RNAs (sncRNAs) such as microRNAs (miRNAs). Here, we review the deleterious effects of exposure during fetal life to EDCs mediated by deregulation of ncRNAs, and specifically miRNAs on PGC differentiation. Moreover, the environmental stress induced by exposure to some EDCs during the embryonic window of development could trigger reproductive dysfunctions transgenerationally transmitted by epigenetic mechanisms with the involvement of miRNAs expressed in germ line cells. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  6. The mouse dead-end gene isoform α is necessary for germ cell and embryonic viability

    PubMed Central

    Bhattacharya, Chitralekha; Aggarwal, Sita; Zhu, Rui; Kumar, Madhu; Zhao, Ming; Meistrich, Marvin L.; Matin, Angabin

    2007-01-01

    Inactivation of the dead-end (Dnd1) gene in the Ter mouse strain results in depletion of primordial germ cells (PGCs) so that mice become sterile. However, on the 129 mouse strain background, loss of Dnd1 also increases testicular germ cell tumor incidence in parallel to PGC depletion. We report that inactivation of Dnd1 also affects embryonic viability in the 129 strain. Mouse Dnd1 encodes two protein isoforms, DND1-isoform α (DND1- α) and DND1-isoform β (DND1-β). Using isoform specific antibodies, we determined DND1-α is expressed in embryos and embryonic gonads whereas DND1-β expression is restricted to germ cells of the adult testis. Our data implicates DND1-α isoform to be necessary for germ cell viability and therefore its loss in Ter mice results in PGC depletion, germ cell tumor development and partial embryonic lethality in the 129 strain. PMID:17291453

  7. Topology of the germ plasm and development of primordial germ cells in inverted amphibian eggs

    NASA Technical Reports Server (NTRS)

    Wakahara, M.; Neff, A. W.; Malacinski, G. M.

    1984-01-01

    Inverted Xenopus eggs have reduced numbers of primordial germ cells (PGCs). The extent of the reduction varies from spawning to spawning. Histologic examination revealed that PGC counts were lowest in inverted eggs which displayed the greatest amount of shift in the vegetal mass of large yolk platelets, although the germ plasm itself always remained localized in the egg's original vegetal hemisphere. Even at blastulation the germ plasm continued to be localized in the egg's original vegetal hemisphere. In many cases, however, it was confined to the periphery of the embryo, which probably accounts for the reduced PGC number in some tadpoles. In other cases it may have been dispersed and therefore not detectable in histologic analyses. Although the altered site of involution in inverted embryos did not influence PGC development, subsequent cell movement patterns apparently did. Those embryos which displayed the largest degree of pattern reversal at the tail-bud stage also exhibited the most extreme reduction in PGC numbers. A brief cold shock (4 degrees C, 10 min) prior to first cleavage leads to a further reduction in PGC numbers in inverted embryos, probably as a result of the displacement of the germ plasm away from its original vegetal pole location.

  8. Topology of the germ plasm and development of primordial germ cells in inverted amphibian eggs

    NASA Technical Reports Server (NTRS)

    Wakahara, M.; Neff, A. W.; Malacinski, G. M.

    1984-01-01

    Inverted Xenopus eggs have reduced numbers of primordial germ cells (PGCs). The extent of the reduction varies from spawning to spawning. Histologic examination revealed that PGC counts were lowest in inverted eggs which displayed the greatest amount of shift in the vegetal mass of large yolk platelets, although the germ plasm itself always remained localized in the egg's original vegetal hemisphere. Even at blastulation the germ plasm continued to be localized in the egg's original vegetal hemisphere. In many cases, however, it was confined to the periphery of the embryo, which probably accounts for the reduced PGC number in some tadpoles. In other cases it may have been dispersed and therefore not detectable in histologic analyses. Although the altered site of involution in inverted embryos did not influence PGC development, subsequent cell movement patterns apparently did. Those embryos which displayed the largest degree of pattern reversal at the tail-bud stage also exhibited the most extreme reduction in PGC numbers. A brief cold shock (4 degrees C, 10 min) prior to first cleavage leads to a further reduction in PGC numbers in inverted embryos, probably as a result of the displacement of the germ plasm away from its original vegetal pole location.

  9. Robust In Vitro Induction of Human Germ Cell Fate from Pluripotent Stem Cells.

    PubMed

    Sasaki, Kotaro; Yokobayashi, Shihori; Nakamura, Tomonori; Okamoto, Ikuhiro; Yabuta, Yukihiro; Kurimoto, Kazuki; Ohta, Hiroshi; Moritoki, Yoshinobu; Iwatani, Chizuru; Tsuchiya, Hideaki; Nakamura, Shinichiro; Sekiguchi, Kiyotoshi; Sakuma, Tetsushi; Yamamoto, Takashi; Mori, Takahide; Woltjen, Knut; Nakagawa, Masato; Yamamoto, Takuya; Takahashi, Kazutoshi; Yamanaka, Shinya; Saitou, Mitinori

    2015-08-06

    Mechanisms underlying human germ cell development are unclear, partly due to difficulties in studying human embryos and lack of suitable experimental systems. Here, we show that human induced pluripotent stem cells (hiPSCs) differentiate into incipient mesoderm-like cells (iMeLCs), which robustly generate human primordial germ cell-like cells (hPGCLCs) that can be purified using the surface markers EpCAM and INTEGRINα6. The transcriptomes of hPGCLCs and primordial germ cells (PGCs) isolated from non-human primates are similar, and although specification of hPGCLCs and mouse PGCs rely on similar signaling pathways, hPGCLC specification transcriptionally activates germline fate without transiently inducing eminent somatic programs. This includes genes important for naive pluripotency and repression of key epigenetic modifiers, concomitant with epigenetic reprogramming. Accordingly, BLIMP1, which represses somatic programs in mice, activates and stabilizes a germline transcriptional circuit and represses a default neuronal differentiation program. Together, these findings provide a foundation for understanding and reconstituting human germ cell development in vitro.

  10. piggyBac transposition into primordial germ cells is an efficient tool for transgenesis in chickens

    PubMed Central

    Park, Tae Sub; Han, Jae Yong

    2012-01-01

    Transgenic birds embody one of the most potent and exciting research tools in biotechnology for agriculture, medicine, and model animals. To date, retrovirus- or lentivirus-mediated transgenesis has been established in chickens and quail. However, despite having a valid technique for viral transduction to achieve transgenic birds, many obstacles exist for practical applications because of relatively low and variable rates of germ-line transmission and transgenic offspring showing transgene silencing, as well as safety issues related to viral vector use. Thus, the generation of transgenic poultry by nonviral integration is a prerequisite for the introduction of biotechnology to practical applications. Herein, we show that a germ-line–competent chicken primordial germ-cell (PGC) line was established with high efficiency of transmission to offspring and that piggyBac transposition into PGCs improved the efficiency of transgenic chicken production and led to high-level transgene expression. GFP transgene-expressing donor PGC-transferred recipient chickens produced donor-derived progenies, and the germ-line transmission efficiency of donor PGCs was 95.2% on average. Subsequently, half of the donor-derived offspring (52.2%) were transgenic chicks because GFP-expressing donor PGCs, in which a transgene was inserted into one chromosome 20, were heterozygous. In all of the transgenic chickens, GFP expression was constant and strong, regardless of age. Our results demonstrate that piggyBac transposition into the chicken PGC line could be the surest way to generate transgenic chickens safely for practical applications. PMID:22645326

  11. Germ Cell Intercellular Bridges

    PubMed Central

    Greenbaum, Michael P.; Iwamori, Tokuko; Buchold, Gregory M.; Matzuk, Martin M.

    2011-01-01

    Stable intercellular bridges are a conserved feature of gametogenesis in multicellular animals observed more than 100 years ago, but their function was unknown. Many of the components necessary for this structure have been identified through the study of cytokinesis in Drosophila; however, mammalian intercellular bridges have distinct properties from those of insects. Mammalian germ cell intercellular bridges are composed of general cytokinesis components with additional germ cell–specific factors including TEX14. TEX14 is an inactive kinase essential for the maintenance of stable intercellular bridges in gametes of both sexes but whose loss specifically impairs male meiosis. TEX14 acts to impede the terminal steps of abscission by competing for essential component CEP55, blocking its interaction in nongerm cells with ALIX and TSG101. Additionally, TEX14-interacting protein RBM44, whose localization in stabile intercellular bridges is limited to pachytene and secondary spermatocytes, may participate in processes such as RNA transport but is nonessential to the maintenance of intercellular bridge stability. PMID:21669984

  12. Basic fibroblast growth factor is critical to reprogramming buffalo (Bubalus bubalis) primordial germ cells into embryonic germ stem cell-like cells.

    PubMed

    Wang, Caizhu; Deng, Yanfei; Chen, Feng; Zhu, Peng; Wei, Jingwei; Luo, Chan; Lu, Fenghua; Yang, Sufang; Shi, Deshun

    2017-03-15

    Primordial germ cells (PGCs) are destined to form gametes in vivo, and they can be reprogrammed into pluripotent embryonic germ (EG) cells in vitro. Buffalo PGC have been reported to be reprogrammed into EG-like cells, but the identities of the major signaling pathways and culture media involved in this derivation remain unclear. Here, the effects of basic fibroblast growth factor (bFGF) and downstream signaling pathways on the reprogramming of buffalo PGCs into EG-like cells were investigated. Results showed bFGF to be critical to buffalo PGCs to dedifferentiate into EG-like cells (20 ng/mL is optimal) with many characteristics of pluripotent stem cells, including alkaline phosphatase (AP) activity, expression of pluripotency marker genes such as OCT4, NANOG, SOX2, SSEA-1, CDH1, and TRA-1-81, and the capacity to differentiate into all three embryonic germ layers. After chemically inhibiting pathways or components downstream of bFGF, data showed that inhibition of the PI3K/AKT pathway led to significantly lower EG cell derivation, while inhibition of P53 activity resulted in an efficiency of EG cell derivation comparable to that in the presence of bFGF. These results suggest that the role of bFGF in PGC-derived EG-like cell generation is mainly due to the activation of the PI3K/AKT/P53 pathway, in particular, the inhibition of P53 function. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Treatment Option Overview (Extragonadal Germ Cell Tumors)

    MedlinePlus

    ... Professional Extragonadal Germ Cell Tumors Treatment Extragonadal Germ Cell Tumors Treatment (PDQ®)–Patient Version General Information About Extragonadal Germ Cell Tumors Go to Health Professional Version Key Points ...

  14. General Information about Extragonadal Germ Cell Tumors

    MedlinePlus

    ... Professional Extragonadal Germ Cell Tumors Treatment Extragonadal Germ Cell Tumors Treatment (PDQ®)–Patient Version General Information About Extragonadal Germ Cell Tumors Go to Health Professional Version Key Points ...

  15. BAX-mediated cell death affects early germ cell loss and incidence of testicular teratomas in Dnd1(Ter/Ter) mice.

    PubMed

    Cook, Matthew S; Coveney, Douglas; Batchvarov, Iordan; Nadeau, Joseph H; Capel, Blanche

    2009-04-15

    A homozygous nonsense mutation (Ter) in murine Dnd1 (Dnd1(Ter/Ter)) results in a significant early loss of primordial germ cells (PGCs) prior to colonization of the gonad in both sexes and all genetic backgrounds tested. The same mutation also leads to testicular teratomas only on the 129Sv/J background. Male mutants on other genetic backgrounds ultimately lose all PGCs with no incidence of teratoma formation. It is not clear how these PGCs are lost or what factors directly control the strain-specific phenotype variation. To determine the mechanism underlying early PGC loss we crossed Dnd1(Ter/Ter) embryos to a Bax-null background and found that germ cells were partially rescued. Surprisingly, on a mixed genetic background, rescued male germ cells also generated fully developed teratomas at a high rate. Double-mutant females on a mixed background did not develop teratomas, but were fertile and produced viable off-spring. However, when Dnd1(Ter/Ter) XX germ cells developed in a testicular environment they gave rise to the same neoplastic clusters as mutant XY germ cells in a testis. We conclude that BAX-mediated apoptosis plays a role in early germ cell loss and protects from testicular teratoma formation on a mixed genetic background.

  16. Primordial germ cell migration in the yellowtail kingfish (Seriola lalandi) and identification of stromal cell-derived factor 1.

    PubMed

    Fernández, J A; Bubner, E J; Takeuchi, Y; Yoshizaki, G; Wang, T; Cummins, S F; Elizur, A

    2015-03-01

    Primordial germ cells (PGCs) are progenitors of the germ cell lineage, giving rise to either spermatogonia or oogonia after the completion of gonadal differentiation. Currently, there is little information on the mechanism of PGCs migration leading to the formation of the primordial gonad in perciform fish. Yellowtail kingfish (Seriola lalandi) (YTK) (order Perciforms) inhabit tropical and temperate waters in the southern hemisphere. Fundamental details into the molecular basis of larval development in this species can be easily studied in Australia, as they are commercially cultured and readily available. In this study, histological analysis of YTK larvae revealed critical time points for the migration of PGCs to the genital ridge, resulting in the subsequent development of the primordial gonad. In YTK larvae at 3, 5, 7 and 10 days post hatch (DPH), PGCs were not yet enclosed by somatic cells, indicating the primordial gonad had not yet started to form. While at 15, 18 and 20 DPH PGCs had already settled at the genital ridge and started to become enclosed by somatic cells indicating the primordial gonad had started to develop. A higher number of PGCs were observed in the larvae at 15 and 18 DPH indicating PGCs proliferation, which corresponds with them becoming enclosed by the somatic cells. Directional migration of PGCs toward the genital ridge is a critical event in the subsequent development of a gonad. In zebrafish, mouse and chicken, stromal-cell derived factor (SDF1) signalling is one of the key molecules for PGC migration. We subsequently isolated from YTK the SDF1 (Slal-SDF1) gene, which encodes for a 98-residue precursor protein with a signal peptide at the N-terminus. There is spatial conservation between fish species of four cysteine residues at positions C9, C11, C34 and C49, expected to form disulphide bonds and stabilize the SDF structure. In YTK, Slal-SDF1 gene expression analyses shows that this gene is expressed in larvae from 1 to 22 DPH and

  17. Extragonadal Germ Cell Cancer (EGC)

    MedlinePlus

    ... germ cells are first seen outside of the embryo in the yolk sac. At about 4 to ... weeks of development, these cells migrate into the embryo where they populate the developing testes or ovaries. ...

  18. Perchlorate Exposure Reduces Primordial Germ Cell Number in Female Threespine Stickleback

    PubMed Central

    Petersen, Ann M.; Earp, Nathanial C.; Redmond, Mandy E.; Postlethwait, John H.; von Hippel, Frank A.; Buck, C. Loren; Cresko, William A.

    2016-01-01

    Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs) begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14–18 days post fertilization (dpf). We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development. PMID:27383240

  19. Perchlorate Exposure Reduces Primordial Germ Cell Number in Female Threespine Stickleback.

    PubMed

    Petersen, Ann M; Earp, Nathanial C; Redmond, Mandy E; Postlethwait, John H; von Hippel, Frank A; Buck, C Loren; Cresko, William A

    2016-01-01

    Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs) begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14-18 days post fertilization (dpf). We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development.

  20. The role of germ cell loss during primordial follicle assembly: a review of current advances.

    PubMed

    Sun, Yuan-Chao; Sun, Xiao-Feng; Dyce, Paul W; Shen, Wei; Chen, Hong

    2017-01-01

    In most female mammals, early germline development begins with the appearance of primordial germ cells (PGCs), and develops to form mature oocytes following several vital processes. It remains well accepted that significant germ cell apoptosis and oocyte loss takes place around the time of birth. The transition of the ovarian environment from fetal to neonatal, coincides with the loss of germ cells and the timing of follicle formation. All told it is common to lose approximately two thirds of germ cells during this transition period. The current consensus is that germ cell loss can be attributed, at least in part, to programmed cell death (PCD). Recently, autophagy has been implicated as playing a part in germ cell loss during the time of parturition. In this review, we discuss the major opinions and mechanisms of mammalian ovarian PCD during the process of germ cell loss. We also pay close attention to the function of autophagy in germ cell loss, and speculate that autophagy may also serve as a critical and necessary process during the establishment of primordial follicle pool.

  1. Production of chicken progeny (Gallus gallus domesticus) from interspecies germline chimeric duck (Anas domesticus) by primordial germ cell transfer.

    PubMed

    Liu, Chunhai; Khazanehdari, Kamal A; Baskar, Vijaya; Saleem, Shazia; Kinne, Joerg; Wernery, Ulrich; Chang, Il-Kuk

    2012-04-01

    The present study aimed to investigate the differentiation of chicken (Gallus gallus domesticus) primordial germ cells (PGCs) in duck (Anas domesticus) gonads. Chimeric ducks were produced by transferring chicken PGCs into duck embryos. Transfer of 200 and 400 PGCs resulted in the detection of a total number of 63.0 ± 54.3 and 116.8 ± 47.1 chicken PGCs in the gonads of 7-day-old duck embryos, respectively. The chimeric rate of ducks prior to hatching was 52.9% and 90.9%, respectively. Chicken germ cells were assessed in the gonad of chimeric ducks with chicken-specific DNA probes. Chicken spermatogonia were detected in the seminiferous tubules of duck testis. Chicken oogonia, primitive and primary follicles, and chicken-derived oocytes were also found in the ovaries of chimeric ducks, indicating that chicken PGCs are able to migrate, proliferate, and differentiate in duck ovaries and participate in the progression of duck ovarian folliculogenesis. Chicken DNA was detected using PCR from the semen of chimeric ducks. A total number of 1057 chicken eggs were laid by Barred Rock hens after they were inseminated with chimeric duck semen, of which four chicken offspring hatched and one chicken embryo did not hatch. Female chimeric ducks were inseminated with chicken semen; however, no fertile eggs were obtained. In conclusion, these results demonstrated that chicken PGCs could interact with duck germinal epithelium and complete spermatogenesis and eventually give rise to functional sperm. The PGC-mediated germline chimera technology may provide a novel system for conserving endangered avian species.

  2. Poultry genetic resource conservation using primordial germ cells

    PubMed Central

    NAKAMURA, Yoshiaki

    2016-01-01

    The majority of poultry genetic resources are maintained in situ in living populations. However, in situ conservation of poultry genetic resources always carries the risk of loss owing to pathogen outbreaks, genetic problems, breeding cessation, or natural disasters. Cryobanking of germplasm in birds has been limited to the use of semen, preventing conservation of the W chromosome and mitochondrial DNA. A further challenge is posed by the structure of avian eggs, which restricts the cryopreservation of ova and fertilized embryos, a technique widely used for mammalian species. By using a unique biological property and accessibility of avian primordial germ cells (PGCs), precursor cells for gametes, which temporally circulate in the vasculature during early development, an avian PGC transplantation technique has been established. To date, several techniques for PGC manipulation including purification, cryopreservation, depletion, and long-term culture have been developed in chickens. PGC transplantation combined with recent advanced PGC manipulation techniques have enabled ex situ conservation of poultry genetic resources in their complete form. Here, the updated technologies for avian PGC manipulation are introduced, and then the concept of a poultry PGC-bank is proposed by considering the biological properties of avian PGCs. PMID:27210834

  3. Drosophila primordial germ cell migration requires epithelial remodeling of the endoderm.

    PubMed

    Seifert, Jessica R K; Lehmann, Ruth

    2012-06-01

    Trans-epithelial migration describes the ability of migrating cells to cross epithelial tissues and occurs during development, infection, inflammation, immune surveillance, wound healing and cancer metastasis. Here we investigate Drosophila primordial germ cells (PGCs), which migrate through the endodermal epithelium. Through live imaging and genetic experimentation we demonstrate that PGCs take advantage of endodermal tissue remodeling to gain access to the gonadal mesoderm and are unable to migrate through intact epithelial tissues. These results are in contrast to the behavior of leukocytes, which actively loosen epithelial junctions to migrate, and raise the possibility that in other contexts in which migrating cells appear to breach tissue barriers, they are actually exploiting existing tissue permeability. Therefore, the use of active invasive programs is not the sole mechanism to infiltrate tissues.

  4. Primordial Germ Cell Specification and Migration.

    PubMed

    Marlow, Florence

    2015-01-01

    Primordial germ cells are the progenitor cells that give rise to the gametes. In some animals, the germline is induced by zygotic transcription factors, whereas in others, primordial germ cell specification occurs via inheritance of maternally provided gene products known as germ plasm. Once specified, the primordial germ cells of some animals must acquire motility and migrate to the gonad in order to survive. In all animals examined, perinuclear structures called germ granules form within germ cells. This review focuses on some of the recent studies, conducted by several groups using diverse systems, from invertebrates to vertebrates, which have provided mechanistic insight into the molecular regulation of germ cell specification and migration.

  5. LIN28 is selectively expressed by primordial and pre-meiotic germ cells in the human fetal ovary.

    PubMed

    Childs, Andrew J; Kinnell, Hazel L; He, Jing; Anderson, Richard A

    2012-09-01

    Germ cell development requires timely transition from primordial germ cell (PGC) self-renewal to meiotic differentiation. This is associated with widespread changes in gene expression, including downregulation of stem cell-associated genes, such as OCT4 and KIT, and upregulation of markers of germ cell differentiation and meiosis, such as VASA, STRA8, and SYCP3. The stem cell-expressed RNA-binding protein Lin28 has recently been demonstrated to be essential for PGC specification in mice, and LIN28 is expressed in human germ cell tumors with phenotypic similarities to human fetal germ cells. We have therefore examined the expression of LIN28 during normal germ cell development in the human fetal ovary, from the PGC stage, through meiosis to the initiation of follicle formation. LIN28 transcript levels were highest when the gonad contained only PGCs, and decreased significantly with increasing gestation, coincident with the onset of germ cell differentiation. Immunohistochemistry revealed LIN28 protein expression to be germ cell-specific at all stages examined. All PGCs expressed LIN28, but at later gestations expression was restricted to a subpopulation of germ cells, which we demonstrate to be primordial and premeiotic germ cells based on immunofluorescent colocalization of LIN28 and OCT4, and absence of overlap with the meiosis marker SYCP3. We also demonstrate the expression of the LIN28 target precursor pri-microRNA transcripts pri-LET7a/f/d and pri-LET-7g in the human fetal ovary, and that expression of these is highest at the PGC stage, mirroring that of LIN28. The spatial and temporal restriction of LIN28 expression and coincident peaks of expression of LIN28 and target pri-microRNAs suggest important roles for this protein in the maintenance of the germline stem cell state and the regulation of microRNA activity in the developing human ovary.

  6. Derivation of putative porcine embryonic germ cells and analysis of their multi-lineage differentiation potential.

    PubMed

    Cong, Yimei; Ma, Jing; Sun, Ruizhen; Wang, Jianyu; Xue, Binghua; Wang, Jiaqiang; Xie, Bingteng; Wang, Juan; Hu, Kui; Liu, Zhonghua

    2013-09-20

    Embryonic germ (EG) cells are cultured pluripotent stem cells derived from the primordial germ cells (PGCs) that migrate from the dorsal mesentery of the hindgut to the developing genital ridge. In this study, the morphology of the porcine genital ridge was assessed in embryos harvested on days 22-30 of pregnancy. PGCs from embryos at these stages were cultured to obtain porcine EG cell lines, and EG-like cells were derived from PGCs from embryos harvested on days 24-28 of pregnancy. The EG-like cells expressed Oct4, Sox2, Nanog, SSEA-3, SSEA-4 and alkaline phosphatase (AP). These cells were able to form embryoid bodies (EBs) in suspension culture and differentiate into cells representative of the three germ layers as verified by a-fetoprotein (AFP), α-smooth muscle actin (α-SMA), and Nestin expression. Spontaneous differentiation from the porcine EG-like cells of delayed passage in vitro showed that they could differentiate into epithelial-like cells, mesenchymal-like cells and neuron-like cells. In vitro directed differentiation generated osteocytes, adipocytes and a variety of neural lineage cells, as demonstrated by alizarin red staining, oil red O staining, and immunofluorescence for neuronal class Ⅲ β-tubulin (Tuj1), glial fibrillary protein (GFAP) and galactosylceramidase (GALC), respectively. These results indicate that porcine EG-like cells have the potential for multi-lineage differentiation and are useful for basic porcine stem cell research. Copyright © 2013. Published by Elsevier Ltd.

  7. Germline Gene Editing in Chickens by Efficient CRISPR-Mediated Homologous Recombination in Primordial Germ Cells

    PubMed Central

    Dimitrov, Lazar; Pedersen, Darlene; Ching, Kathryn H.; Yi, Henry; Collarini, Ellen J.; Izquierdo, Shelley; van de Lavoir, Marie-Cecile; Leighton, Philip A.

    2016-01-01

    The CRISPR/Cas9 system has been applied in a large number of animal and plant species for genome editing. In chickens, CRISPR has been used to knockout genes in somatic tissues, but no CRISPR-mediated germline modification has yet been reported. Here we use CRISPR to target the chicken immunoglobulin heavy chain locus in primordial germ cells (PGCs) to produce transgenic progeny. Guide RNAs were co-transfected with a donor vector for homology-directed repair of the double-strand break, and clonal populations were selected. All of the resulting drug-resistant clones contained the correct targeting event. The targeted cells gave rise to healthy progeny containing the CRISPR-targeted locus. The results show that gene-edited chickens can be obtained by modifying PGCs in vitro with the CRISPR/Cas9 system, opening up many potential applications for efficient genetic modification in birds. PMID:27099923

  8. Germline Gene Editing in Chickens by Efficient CRISPR-Mediated Homologous Recombination in Primordial Germ Cells.

    PubMed

    Dimitrov, Lazar; Pedersen, Darlene; Ching, Kathryn H; Yi, Henry; Collarini, Ellen J; Izquierdo, Shelley; van de Lavoir, Marie-Cecile; Leighton, Philip A

    2016-01-01

    The CRISPR/Cas9 system has been applied in a large number of animal and plant species for genome editing. In chickens, CRISPR has been used to knockout genes in somatic tissues, but no CRISPR-mediated germline modification has yet been reported. Here we use CRISPR to target the chicken immunoglobulin heavy chain locus in primordial germ cells (PGCs) to produce transgenic progeny. Guide RNAs were co-transfected with a donor vector for homology-directed repair of the double-strand break, and clonal populations were selected. All of the resulting drug-resistant clones contained the correct targeting event. The targeted cells gave rise to healthy progeny containing the CRISPR-targeted locus. The results show that gene-edited chickens can be obtained by modifying PGCs in vitro with the CRISPR/Cas9 system, opening up many potential applications for efficient genetic modification in birds.

  9. DAZ Family Proteins, Key Players for Germ Cell Development.

    PubMed

    Fu, Xia-Fei; Cheng, Shun-Feng; Wang, Lin-Qing; Yin, Shen; De Felici, Massimo; Shen, Wei

    2015-01-01

    DAZ family proteins are found almost exclusively in germ cells in distant animal species. Deletion or mutations of their encoding genes usually severely impair either oogenesis or spermatogenesis or both. The family includes Boule (or Boll), Dazl (or Dazla) and DAZ genes. Boule and Dazl are situated on autosomes while DAZ, exclusive of higher primates, is located on the Y chromosome. Deletion of DAZ gene is the most common causes of infertility in humans. These genes, encoding for RNA binding proteins, contain a highly conserved RNA recognition motif and at least one DAZ repeat encoding for a 24 amino acids sequence able to bind other mRNA binding proteins. Basically, Daz family proteins function as adaptors for target mRNA transport and activators of their translation. In some invertebrate species, BOULE protein play a pivotal role in germline specification and a conserved regulatory role in meiosis. Depending on the species, DAZL is expressed in primordial germ cells (PGCs) and/or pre-meiotic and meiotic germ cells of both sexes. Daz is found in fetal gonocytes, spermatogonia and spermatocytes of adult testes. Here we discuss DAZ family genes in a phylogenic perspective, focusing on the common and distinct features of these genes, and their pivotal roles during gametogenesis evolved during evolution.

  10. Recent Advances on New Discovered Molecular Targets in Testicular Germ Cell Tumors.

    PubMed

    Chieffi, Paolo

    2017-10-03

    Testicular germ cell tumor (TGCT) is the most common solid malignancy occurring in young men between 20 and 34 years of age, and its incidence has increased significantly over the last decades. TGCTs can be subdivided into seminoma and non-seminoma a germ cell tumor (NSGCTs) which includes yolk sac tumor, choriocarcinoma, embryonal cell carcinoma, and teratoma. Seminomas and NSGCTs present significant differences in therapy, prognosis, and both show characteristics of the Primordial Germ Cells (PGCs). A large number of new biomarkers have given further advantages to discriminate the different histotypes and could represent useful novel molecular targets for anticancer strategies. A deeper understanding of the pathogenesis of TGCTs is likely to significantly improve not only our knowledge on stem cells and oncogenesis but also the disease management with more selective tumor treatment. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. Palifosfamide in Treating Patients With Recurrent Germ Cell Tumors

    ClinicalTrials.gov

    2015-06-11

    Adult Central Nervous System Germ Cell Tumor; Adult Teratoma; Malignant Extragonadal Germ Cell Tumor; Malignant Extragonadal Non-Seminomatous Germ Cell Tumor; Extragonadal Seminoma; Recurrent Malignant Testicular Germ Cell Tumor; Recurrent Ovarian Germ Cell Tumor; Stage IV Extragonadal Non-Seminomatous Germ Cell Tumor; Stage IV Extragonadal Seminoma; Stage IV Ovarian Germ Cell Tumor

  12. Erasure of DNA methylation, genomic imprints, and epimutations in a primordial germ-cell model derived from mouse pluripotent stem cells

    PubMed Central

    Miyoshi, Norikatsu; Stel, Jente M.; Shioda, Keiko; Qu, Na; Odajima, Junko; Mitsunaga, Shino; Zhang, Xiangfan; Nagano, Makoto; Hochedlinger, Konrad; Isselbacher, Kurt J.; Shioda, Toshi

    2016-01-01

    The genome-wide depletion of 5-methylcytosines (5meCs) caused by passive dilution through DNA synthesis without daughter strand methylation and active enzymatic processes resulting in replacement of 5meCs with unmethylated cytosines is a hallmark of primordial germ cells (PGCs). Although recent studies have shown that in vitro differentiation of pluripotent stem cells (PSCs) to PGC-like cells (PGCLCs) mimics the in vivo differentiation of epiblast cells to PGCs, how DNA methylation status of PGCLCs resembles the dynamics of 5meC erasure in embryonic PGCs remains controversial. Here, by differential detection of genome-wide 5meC and 5-hydroxymethylcytosine (5hmeC) distributions by deep sequencing, we show that PGCLCs derived from mouse PSCs recapitulated the process of genome-wide DNA demethylation in embryonic PGCs, including significant demethylation of imprint control regions (ICRs) associated with increased mRNA expression of the corresponding imprinted genes. Although 5hmeCs were also significantly diminished in PGCLCs, they retained greater amounts of 5hmeCs than intragonadal PGCs. The genomes of both PGCLCs and PGCs selectively retained both 5meCs and 5hmeCs at a small number of repeat sequences such as GSAT_MM, of which the significant retention of bisulfite-resistant cytosines was corroborated by reanalysis of previously published whole-genome bisulfite sequencing data for intragonadal PGCs. PSCs harboring abnormal hypermethylation at ICRs of the Dlk1-Gtl2-Dio3 imprinting cluster diminished these 5meCs upon differentiation to PGCLCs, resulting in transcriptional reactivation of the Gtl2 gene. These observations support the usefulness of PGCLCs in studying the germline epigenetic erasure including imprinted genes, epimutations, and erasure-resistant loci, which may be involved in transgenerational epigenetic inheritance. PMID:27486249

  13. New perspective on molecular markers as promising therapeutic targets in germ cell tumors

    PubMed Central

    Chieffi, Paolo

    2016-01-01

    Summary Testicular germ cell tumors (TGCTs) are the most frequent solid malignant tumors in men 20–40 years of age and the most frequent cause of death from solid tumors in this age group. TGCTs comprise two major histologic groups: seminomas and non-seminomas germ cell tumors (NSGCTs). NSGCTs can be further divided into embryonal carcinoma, Teratoma, yolk sac tumor, and choriocarcinoma. Seminomas and NSGCTs present significant differences in clinical features, therapy, and prognosis, and both show characteristics of the Primordial Germ Cells (PGCs). Many discovered biomarkers including HMGA1, GPR30, Aurora-B, estrogen receptor β, and others have given further advantages to discriminate between histological subgroups and could represent useful therapeutic targets. PMID:27195201

  14. Reduction in E-cadherin expression fosters migration of Xenopus laevis primordial germ cells.

    PubMed

    Baronsky, Thilo; Dzementsei, Aliaksandr; Oelkers, Marieelen; Melchert, Juliane; Pieler, Tomas; Janshoff, Andreas

    2016-03-14

    The transition from passive to active migration of primordial germ cells in Xenopus embryos correlates with a reduction in overall adhesion to surrounding endodermal cells as well as with reduced E-cadherin expression. Single cell force spectroscopy, in which cells are brought into brief contact with a gold surface functionalized with E-cadherin constructs, allows for a quantitative estimate of functional E-cadherin molecules on the cell surface. The adhesion force between migratory PGCs and the cadherin-coated surface was almost identical to cells where E-cadherin was knocked down by morpholino oligonucleotides (180 pN). In contrast, non-migratory PGCs display significantly higher adhesion forces (270 pN) on E-cadherin functionalised surfaces. On the basis of these observations, we propose that migration of PGCs in Xenopus embryos is regulated via modulation of E-cadherin expression levels, allowing these cells to move more freely if the level of E-cadherin is reduced.

  15. SOX17 Is a Critical Specifier of Human Primordial Germ Cell Fate

    PubMed Central

    Irie, Naoko; Weinberger, Leehee; Tang, Walfred W.C.; Kobayashi, Toshihiro; Viukov, Sergey; Manor, Yair S.; Dietmann, Sabine; Hanna, Jacob H.; Surani, M. Azim

    2015-01-01

    Summary Specification of primordial germ cells (PGCs) marks the beginning of the totipotent state. However, without a tractable experimental model, the mechanism of human PGC (hPGC) specification remains unclear. Here, we demonstrate specification of hPGC-like cells (hPGCLCs) from germline competent pluripotent stem cells. The characteristics of hPGCLCs are consistent with the embryonic hPGCs and a germline seminoma that share a CD38 cell-surface marker, which collectively defines likely progression of the early human germline. Remarkably, SOX17 is the key regulator of hPGC-like fate, whereas BLIMP1 represses endodermal and other somatic genes during specification of hPGCLCs. Notable mechanistic differences between mouse and human PGC specification could be attributed to their divergent embryonic development and pluripotent states, which might affect other early cell-fate decisions. We have established a foundation for future studies on resetting of the epigenome in hPGCLCs and hPGCs for totipotency and the transmission of genetic and epigenetic information. PMID:25543152

  16. Treatment Option Overview (Ovarian Germ Cell Tumors)

    MedlinePlus

    ... Tube, & Primary Peritoneal Cancer Screening Research Ovarian Germ Cell Tumors Treatment (PDQ®)–Patient Version General Information About Ovarian Germ Cell Tumors Go to Health Professional Version Key Points ...

  17. General Information about Ovarian Germ Cell Tumors

    MedlinePlus

    ... Tube, & Primary Peritoneal Cancer Screening Research Ovarian Germ Cell Tumors Treatment (PDQ®)–Patient Version General Information About Ovarian Germ Cell Tumors Go to Health Professional Version Key Points ...

  18. Retinoic acid promotes the proliferation of primordial germ cell-like cells differentiated from mouse skin-derived stem cells in vitro.

    PubMed

    Tan, Hui; Wang, Jun-Jie; Cheng, Shun-Feng; Ge, Wei; Sun, Yuan-Chao; Sun, Xiao-Feng; Sun, Rui; Li, Lan; Li, Bo; Shen, Wei

    2016-02-01

    Skin-derived stem cells (SDSCs) have the potential to differentiate into gametes and are a potential resource for research and clinical applications. Sufficient amount of primordial germ cells (PGCs) is an important requirement for successful differentiation of SDSCs into gametes in vitro. Retinoic acid (RA), a vitamin A-derived small lipophilic molecule, promotes the growth of PGCs in vivo; however, the role of RA on the proliferation of PGC-like cells (PGCLCs) derived from SDSCs remains unknown. In this study, SDSCs were induced to differentiate into the embryoid body and cocultured with mouse fibroblasts to form PGCLCs. The proliferation of PGCLCs with the presence of various concentrations of RA was investigated in vitro. Immunofluorescence labeling showed that the 5-Bromo-2-deoxyUridine-positive ratio of PGCLCs was increased after the cells were treated with 5-μM RA, and flow cytometry results showed that the number of cells in the S phase was increased significantly. The messenger RNA expression levels of cell cycle-related genes, CCND1 and CDK2, were also increased. Furthermore, RA effectively promoted the external proliferation of endogenous PGCs when 11.5-days postcoitum fetal mouse genital ridges were cultured in vitro. In conclusion, 5-μM RA promoted the proliferation of SDSCs-derived PGCLCs and endogenous PGCs. Our study will provide a valuable model system for studying the differentiation of stem cells into gametes in vitro.

  19. RA induces differentiation of multipotent P19 cells towards male germ cell.

    PubMed

    Zhang, Lei; Tang, Jiangjing; Haines, Christopher J; Feng, Huai; Teng, Xiaoming; Han, Yibing

    2015-01-01

    Generating male germ cells in vitro from multipotent stem cells is still a challenge for stem cell biologists. The difficulty is caused by the lack of knowledge about spermatogenesis molecular-controlling mechanisms. In vivo, PGCs differentiate into male germ cells in a very complicated environment through many middle steps. In this study, we use the pluripotent p19 cells to test their responses to different retinoic acid (RA) concentrations by evaluating markers for stem cells (bmp4, egr3), primordial germ cells (ddx4), spermatogonia (c-kit), premeiotic cells (stra8), and male germ cells (dazl and plzf). We have found that cyp26b1, which will catalyze RA, increases dramatically in p19 cells 1 d after RA treatment. Bmp3, egr3, and stra8 are stimulated after 1 d of RA treatment and then recover to normal after 3 d of RA treatment. C-kit keeps being expressed when treated with 10 nM-4 μM RA. Dazl and plzf are gained after 3 d of stimulation. The morphology of RA (100 nM-4 μM)-treated cells changes distinctively, and cell colonies are formed. Typical neural cell-like and germ cell-like morphologies appear in the 100 nM and 4 μM RA groups, respectively. We conclude that 100-500 nM RA can cause responses in p19 cells, but a high concentration of RA (1-4 μM) can drive these pluripotent cells' differentiation towards male germ cells. However, high concentrations of RA are also toxic. Some colonies that survived from 4 μM RA begin to express ddx4 and c-kit. Selection of the c-kit(+), dazl(+), and ddx4(+) cells after RA stimulation and creating a special culture medium for their propagation might benefit successful spermatogenesis induction in vitro.

  20. HISTORY OF GERM CELL MUTAGENESIS

    EPA Science Inventory

    Much of the early work on germ cell mutation analysis was conducted with nonmammalian species, but this historical overview will begin with the rodent studies that provided quantitative data on induced mutations. The initial studies of mutation induction utilized the newly develo...

  1. HISTORY OF GERM CELL MUTAGENESIS

    EPA Science Inventory

    Much of the early work on germ cell mutation analysis was conducted with nonmammalian species, but this historical overview will begin with the rodent studies that provided quantitative data on induced mutations. The initial studies of mutation induction utilized the newly develo...

  2. Conserved mechanisms for germ cell-specific localization of nanos3 transcripts in teleost species with aquaculture significance.

    PubMed

    Škugor, Adrijana; Slanchev, Krasimir; Torgersen, Jacob Seilø; Tveiten, Helge; Andersen, Øivind

    2014-06-01

    The importance of the aquaculture production is increasing with the declining global fish stocks, but early sexual maturation in several farmed species reduces muscle growth and quality, and escapees could have a negative impact on wild populations. A possible solution to these problems is the production of sterile fish by ablation of the embryonic primordial germ cells (PGCs), a technique developed in zebrafish. Cell-specific regulation of mRNA stability is crucial for proper specification of the germ cell lineage and commonly involves microRNA (miRNA)-mediated degradation of targeted mRNAs in somatic cells. This study reports on the functional roles of conserved motifs in the 3' untranslated region (UTR) of the miRNA target gene nanos3 identified in Atlantic cod, Atlantic salmon, and zebrafish. The 3'UTR of cod nanos3 was sufficient for targeting the expression of green fluorescent protein (GFP) to the presumptive PGCs in injected embryos of the three phylogenetically distant species. 3'UTR elements of importance for PGC-specific expression were further examined by fusing truncated 3'UTR variants of cod nanos3 to GFP followed by injections in zebrafish embryos. The expression patterns of the GFP constructs in PGCs and somatic cells suggested that the proximal U-rich region is responsible for the PGC-specific stabilization of the endogenous nanos3 mRNA. Morpholino-mediated downregulation of the RNA-binding protein Dead end (DnD), a PGC-specific inhibitor of miRNA action, abolished the fluorescence of the PGCs in cod and zebrafish embryos, suggesting a conserved DnD-dependent mechanism for germ cell survival and migration.

  3. The Ter Mutation In The Dead End Gene Causes Germ Cell Loss And Testicular Germ Cell Tumours

    SciTech Connect

    Youngren, Kirsten K.; Coveney, Douglas; Peng, Xiaoning; Bhattacharya, Chitralekha; Schmidt, Laura S.; Nickerson, Michael L.; Lamb, Bruce T.; Deng Jian Min; Behringer, Richard R.; Capel, Blanche; Rubin, Edward M.; Nadeau, Joseph H.; Matin, Angabin

    2005-01-01

    In mice, the Ter mutation causes primordial germ cell (PGC) loss in all genetic backgrounds1. Ter is also a potent modifier of spontaneous testicular germ cell tumour (TGCT) susceptibility in the 129 family of inbred strains, and markedly increases TGCT incidence in 129-Ter/Ter males2 4. In 129-Ter/Ter mice, some of the remaining PGCs transform into undifferentiated pluripotent embryonal carcinoma cells2 6, and after birth differentiate into various cells and tissues that compose TGCTs. Here, we report the positional cloning of Ter, revealing a point mutation that introduces a termination codon in the mouse orthologue (Dnd1) of the zebrafish dead end (dnd) gene. PGC deficiency is corrected both with bacterial artificial chromosomes that contain Dnd1 and with a Dnd1-encoding transgene. Dnd1 is expressed in fetal gonads during the critical period when TGCTs originate. DND1 has an RNA recognition motif and is most similar to the apobec complementation factor, a component of the cytidine t o uridine RNA-editing complex. These results suggest that Ter may adversely affect essential aspects of RNA biology during PGC development. DND1 is the first protein known to have an RNA recognition motif directly implicated as a heritable cause of spontaneous tumorigenesis. TGCT development in the 129-Ter mouse strain models paediatric TGCT in humans. This work will have important implications for our understanding of the genetic control of TGCT pathogenesis and PGC biology.

  4. Molecular and biological aspects of early germ cell development in interspecies hybrids between chickens and pheasants.

    PubMed

    Kang, Seok Jin; Sohn, Sea Hwan; Kang, Kyung Soo; Lee, Hyung Chul; Lee, Seul Ki; Choi, Jin Won; Han, Jae Yong

    2011-03-01

    Interspecific hybrids provide insights into fundamental genetic principles, and may prove useful for biotechnological applications and as tools for the conservation of endangered species. In the present study, interspecies hybrids were generated between the Korean ring-necked pheasant (Phasianus colchicus) and the White Leghorn chicken (Gallus gallus domesticus). We determined whether these hybrids were good recipients for the production of germline chimeric birds. PCR-based species-specific amplification and karyotype analyses showed that the hybrids inherited genetic material from both parents. Evaluation of biological function indicated that the growth rates of hybrids during the exponential phase (body weight/week) were similar to those of the pheasant but not the chicken, and that the incubation period for hatching was significantly different from that of both parents. Primordial germ cells (PGCs) of hybrids reacted with a pheasant PGC-specific antibody and circulated normally in blood vessels. The peak time of hybrid PGC migration was equivalent to that of the pheasant. In late embryonic stages, germ cells were detected by the QCR1 antibody on 15 d male gonads and were normally localized in the seminiferous cords. We examined the migration ability and developmental localization of exogenous PGCs transferred into the blood vessels of 63 h hybrid embryos. Donor-derived PGCs reacted with a donor-specific antibody were detected on 7 d gonads and the seminiferous tubules of hatchlings. Therefore, germ cell transfer into developing embryos of an interspecies hybrid can be efficiently used for the conservation of threatened animals and endangered species, and many biotechnological applications. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Identification of Potential Germ-Cell Mutagens

    EPA Science Inventory

    The existence of agents that can induce germ-cell mutations in experimental systems has been recognized since 1927 with the discovery of the ability of X-rays to induce such mutations in Drosophila. Various rodent-based germ-cell mutation assays have been developed, and ~50 germ...

  6. Identification of Potential Germ-Cell Mutagens

    EPA Science Inventory

    The existence of agents that can induce germ-cell mutations in experimental systems has been recognized since 1927 with the discovery of the ability of X-rays to induce such mutations in Drosophila. Various rodent-based germ-cell mutation assays have been developed, and ~50 germ...

  7. A spindle-independent cleavage pathway controls germ cell formation in Drosophila

    PubMed Central

    Cinalli, Ryan M.; Lehmann, Ruth

    2013-01-01

    The primordial germ cells (PGCs) are the first cells to form during Drosophila melanogaster embryogenesis. While the process of somatic cell formation has been studied in detail, the mechanics of PGC formation are poorly understood. Here, using 4D multi-photon imaging combined with genetic and pharmacological manipulations, we find that PGC formation requires an anaphase spindle-independent cleavage pathway. In addition to utilizing core regulators of cleavage, including the small GTPase RhoA (Drosophila Rho) and the Rho associated kinase, ROCK (Drosophila Rok), we show that this pathway requires Germ cell-less (Gcl), a conserved BTB-domain protein not previously implicated in cleavage mechanics. This alternate form of cell formation suggests that organisms have evolved multiple molecular strategies for regulating the cytoskeleton during cleavage. PMID:23728423

  8. Primordial Germ Cell Specification and Migration

    PubMed Central

    Marlow, Florence

    2015-01-01

    Primordial germ cells are the progenitor cells that give rise to the gametes. In some animals, the germline is induced by zygotic transcription factors, whereas in others, primordial germ cell specification occurs via inheritance of maternally provided gene products known as germ plasm. Once specified, the primordial germ cells of some animals must acquire motility and migrate to the gonad in order to survive. In all animals examined, perinuclear structures called germ granules form within germ cells. This review focuses on some of the recent studies, conducted by several groups using diverse systems, from invertebrates to vertebrates, which have provided mechanistic insight into the molecular regulation of germ cell specification and migration. PMID:26918157

  9. Generation of transgenic quail through germ cell-mediated germline transmission.

    PubMed

    Shin, Sang Su; Kim, Tae Min; Kim, Sun Young; Kim, Tae Wan; Seo, Hee Won; Lee, Seul Ki; Kwon, Se Chang; Lee, Gwan Sun; Kim, Heebal; Lim, Jeong Mook; Han, Jae Yong

    2008-07-01

    Here, we describe the production of transgenic quail via a germline transmission system using postmigratory gonadal primordial germ cells (gPGCs). gPGCs retrieved from the embryonic gonads of 5-day-old birds were transduced with a lentiviral vector and subsequently transferred into recipient embryos. Testcross and genetic analyses revealed that among three germline chimeric G0 quail, one male produced transgenic offspring; of 310 hatchlings from the transgenic germline chimera, 24 were identified as donor-derived offspring, and 6 were transgenic (6/310, 1.9%). Conventional transgenesis using stage X blastodermal embryos was also conducted, but the efficiency of transgenesis was similar between the two systems (<1.6 vs. 1.9% for the conventional and gPGC-mediated systems, respectively). However, substantial advantages can be gained from gPGC-mediated method in that it enables an induced germline modification, whereas direct retroviral transfer to stage X embryos causes mosaic integration. The use of gonadal PGCs for transgenesis may lead to the production of bioreactors.

  10. Improving the efficiency for generation of genome-edited zebrafish by labeling primordial germ cells.

    PubMed

    Dong, Zhangji; Dong, Xiaohua; Jia, Wenshang; Cao, Shasha; Zhao, Qingshun

    2014-10-01

    Although CRISPR/Cas, a new versatile genome-editing tool, has been widely used in a variety of species including zebrafish, an important vertebrate model animal for biomedical research, the low efficiency of germline transmission of induced mutations and particularly knockin alleles made subsequent screening for heritable offspring tedious, time-consuming, expensive and at times impossible. In this study, we reported a method for improving the efficiency of germline transmission screening for generation of genome-edited zebrafish mutants. Co-microinjecting yfp-nanos3 mRNA with Cas9 mRNA, sgRNA and single strand DNA donor to label the distribution of microinjected nucleotides in PGCs (primordial germ cells), we demonstrated that founders carrying labeled PGCs produced much higher numbers of knockin and knockout progeny. In comparison with the common practice of selecting founders by genotyping fin clips, our new strategy of selecting founders with tentatively fluorescent-labeled PGCs significantly increase the ease and speed of generating heritable knocking and knockout animals with CRISPR/Cas9.

  11. Loss of Dnd1 facilitates the cultivation of genital ridge-derived rat embryonic germ cells.

    PubMed

    Northrup, Emily; Eisenblätter, Regina; Glage, Silke; Rudolph, Cornelia; Dorsch, Martina; Schlegelberger, Brigitte; Hedrich, Hans-Jürgen; Zschemisch, Nils-Holger

    2011-08-01

    Pluripotent cells referred to as embryonic germ cells (EGCs) can be derived from the embryonic precursors of the mature gametes: the primordial germ cells (PGCs). A homozygous mutation (ter) of the dead-end homolog 1 gene (Dnd1) in the rat causes gonadal teratocarcinogenesis and sterility due to neoplastic transformation and loss of germ cells. We mated heterozygous ter/+ WKY-Dnd1(ter)/Ztm rats and were able to cultivate the first genital ridge-derived EGCs of the rat embryo at day 14.5 post coitum (pc). Genotyping revealed that ten EGC lines were Dnd1 deficient, while only one wild type cell line had survived in culture. This suggests that the inactivation of the putative tumor suppressor gene Dnd1 facilitates the immortalization of late EGCs in vitro. Injection of the wild type EGCs into blastocysts resulted in the first germ-line competent chimeras. These new pluripotent rat EGCs offer an innovative approach for studies on germ cell tumor development as well as a new tool for genetic manipulations in rats.

  12. Mitochondrial trafficking through Rhot1 is involved in the aggregation of germinal granule components during primordial germ cell formation in Xenopus embryos.

    PubMed

    Tada, Haru; Taira, Yuya; Morichika, Keisuke; Kinoshita, Tsutomu

    2016-10-01

    In many animals, the germ plasm is sufficient and necessary for primordial germ cell (PGC) formation. It contains germinal granules and abundant mitochondria (germline-Mt). However, the role of germline-Mt in germ cell formation remains poorly understood. In Xenopus, the germ plasm is distributed as many small islands at the vegetal pole, which gradually aggregates to form a single large mass in each of the four vegetal pole cells at the early blastula stage. Polymerized microtubules and the adapter protein kinesin are required for the aggregation of germ plasm. However, it remains unknown whether germline-Mt trafficking is important for the cytoplasmic transport of germinal granules during germ plasm aggregation. In this study, we focused on the mitochondrial small GTPase protein Rhot1 to inhibit mitochondrial trafficking during the germ plasm aggregation. Expression of Rhot1ΔC, which lacks the C-terminal mitochondrial transmembrane domain, inhibited the aggregation of germline-Mt during early development. In Rhot1-inhibited embryos, germinal granule components did not aggregate during cleavage stages, which reduced the number of PGCs on the genital ridge at tail-bud stage. These results suggest that mitochondrial trafficking is involved in the aggregation of germinal granule components, which are essential for the formation of PGCs.

  13. Primordial germ cell differentiation of nuclear transfer embryonic stem cells using surface modified electroconductive scaffolds.

    PubMed

    Eslami-Arshaghi, Tarlan; Vakilian, Saeid; Seyedjafari, Ehsan; Ardeshirylajimi, Abdolreza; Soleimani, Masoud; Salehi, Mohammad

    2017-04-01

    A combination of nanotopographical cues and surface modification of collagen and fibronectin is a potential platform in primordial germ cells (PGCs) differentiation. In the present study, the synergistic effect of nanotopography and surface modification on differentiation of nuclear transfer embryonic stem cells (nt-ESCs) toward PGC lineage was investigated. In order to achieve this goal, poly-anyline (PANi) was mix within poly-L-lactic acid (PLLA). Afterward, the random composite mats were fabricated using PLLA and PANi mix solution. The nanofiber topography notably upregulated the expressions of prdm14, mvh and c-kit compared with tissue culture polystyrene (TCP). Moreover, the combination of nanofiber topography and surface modification resulted in more enhancement of PGCs differentiation compared with non-modified nanofibrous scaffold. Additionally, gene expression results showed that mvh and c-kit were expressed at higher intensity in cells exposed to collagen and fibronectin rather than collagen or fibronectin solitary. These results demonstrated the importance of combined effect of collagen and fibronectin in order to develop a functional extracellular matrix (ECM) mimic in directing stem cell fate and the potential of such biofunctional scaffolds for treatment of infertility.

  14. SET domain-containing protein 5 is required for expression of primordial germ cell specification-associated genes in murine embryonic stem cells.

    PubMed

    Yu, Seung Eun; Kim, Min Seong; Park, Su Hyung; Yoo, Byong Chul; Kim, Kyung Hee; Jang, Yeun Kyu

    2017-07-01

    Primordial germ cell (PGC) specification is one of the most fundamental processes in developmental biology. Because PGCs are a common source of both gametes, generation of PGCs from embryonic stem cells (ESCs) is a useful model for analysing the germ line lineage. Although several studies focused on the role of epigenetic regulation on PGC differentiation from ESCs in vitro have been published, germ line commitment remains poorly understood. Here, we show that SET domain-containing protein (Setd5), which has a previously unknown function, is essential for regulating germ cell-associated genes in murine ESCs (mESCs). Even though Setd5 knockdown with 3 distinct shRNAs did not affect expression of pluripotency genes or levels of global histone methylation, all 3 shRNAs significantly diminished the expression of early and late-stage PGC-associated genes. Furthermore, our immunoprecipitation assay showed that Setd5 can interact with Tbl1xr1 and Ctr9, which are components of 2 different transcriptional regulatory complexes, namely, NcoR1 corepressor complex and Paf1 complex, respectively, in mESCs. Taken together, our data suggest that Setd5 is required for maintaining PGC-associated genes and Setd5-associated protein complexes containing Tbl1xr1 and Ctr9, which in turn are likely involved in regulating germ cell-related genes in mESCs. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Effects of specific and prolonged expression of zebrafish growth factors, Fgf2 and Lif in primordial germ cells in vivo

    SciTech Connect

    Wong, Ten-Tsao; Collodi, Paul

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer We discovered that nanos3 3 Prime UTR prolonged PGC-specific protein expression up to 26 days. Black-Right-Pointing-Pointer Expression of Fgf2 in PGCs significantly increased PGC number at later developmental stages. Black-Right-Pointing-Pointer Expression of Lif in PGCs resulted in a significant disruption of PGC migration. Black-Right-Pointing-Pointer Lif illicited its effect on PGC migration through Lif receptor a. Black-Right-Pointing-Pointer Our approach could be used to achieve prolonged PGC-specific expression of other proteins. -- Abstract: Primordial germ cells (PGCs), specified early in development, proliferate and migrate to the developing gonad before sexual differentiation occurs in the embryo and eventually give rise to spermatogonia or oogonia. In this study, we discovered that nanos3 3 Prime UTR, a common method used to label PGCs, not only directed PGC-specific expression of DsRed but also prolonged this expression up to 26 days post fertilization (dpf) when DsRed-nanos3 3 Prime UTR hybrid mRNAs were introduced into 1- to 2-cell-stage embryos. As such, we employed this knowledge to express zebrafish leukemia inhibitory factor (Lif), basic fibroblast growth factor (Fgf2) and bone morphogenetic protein 4 (Bmp4) in the PGCs and evaluate their effects on PGC development in vivo for over a period of 3 weeks. The results show that expression of Fgf2 significantly increased PGC number at 14- and 21-dpf while Bmp4 resulted in severe ventralization and death of the embryos by 3 days. Expression of Lif resulted in a significant disruption of PGC migration. Mopholino knockdown experiments indicated that Lif illicited its effect on PGC migration through Lif receptor a (Lifra) but not Lifrb. The general approach described in this study could be used to achieve prolonged PGC-specific expression of other proteins to investigate their roles in germ cell and gonad development. The results also indicate that zebrafish PGCs

  16. Autonomy in specification of primordial germ cells and their passive translocation in the sea urchin.

    PubMed

    Yajima, Mamiko; Wessel, Gary M

    2012-10-01

    The process of germ line determination involves many conserved genes, yet is highly variable. Echinoderms are positioned at the base of Deuterostomia and are crucial to understanding these evolutionary transitions, yet the mechanism of germ line specification is not known in any member of the phyla. Here we demonstrate that small micromeres (SMics), which are formed at the fifth cell division of the sea urchin embryo, illustrate many typical features of primordial germ cell (PGC) specification. SMics autonomously express germ line genes in isolated culture, including selective Vasa protein accumulation and transcriptional activation of nanos; their descendants are passively displaced towards the animal pole by secondary mesenchyme cells and the elongating archenteron during gastrulation; Cadherin (G form) has an important role in their development and clustering phenotype; and a left/right integration into the future adult anlagen appears to be controlled by a late developmental mechanism. These results suggest that sea urchin SMics share many more characteristics typical of PGCs than previously thought, and imply a more widely conserved system of germ line development among metazoans.

  17. Dazl Functions in Maintenance of Pluripotency and Genetic and Epigenetic Programs of Differentiation in Mouse Primordial Germ Cells In Vivo and In Vitro

    PubMed Central

    Haston, Kelly M.; Tung, Joyce Y.; Reijo Pera, Renee A.

    2009-01-01

    Background Mammalian germ cells progress through a unique developmental program that encompasses proliferation and migration of the nascent primordial germ cell (PGC) population, reprogramming of nuclear DNA to reset imprinted gene expression, and differentiation of mature gametes. Little is known of the genes that regulate quantitative and qualitative aspects of early mammalian germ cell development both in vivo, and during differentiation of germ cells from mouse embryonic stem cells (mESCs) in vitro. Methodology and Principal Findings We used a transgenic mouse system that enabled isolation of small numbers of Oct4ΔPE:GFP-positive germ cells in vivo, and following differentiation from mESCs in vitro, to uncover quantitate and qualitative phenotypes associated with the disruption of a single translational regulator, Dazl. We demonstrate that disruption of Dazl results in a post-migratory, pre-meiotic reduction in PGC number accompanied by aberrant expression of pluripotency genes and failure to erase and re-establish genomic imprints in isolated male and female PGCs, as well as subsequent defect in progression through meiosis. Moreover, the phenotypes observed in vivo were mirrored by those in vitro, with inability of isolated mutant PGCs to establish pluripotent EG (embryonic germ) cell lines and few residual Oct-4-expressing cells remaining after somatic differentiation of mESCs carrying a Dazl null mutation. Finally, we observed that even within undifferentiated mESCs, a nascent germ cell subpopulation exists that was effectively eliminated with ablation of Dazl. Conclusions and Significance This report establishes the translational regulator Dazl as a component of pluripotency, genetic, and epigenetic programs at multiple time points of germ cell development in vivo and in vitro, and validates use of the ESC system to model and explore germ cell biology. PMID:19468308

  18. Germ cells are not the primary factor for sexual fate determination in goldfish.

    PubMed

    Goto, Rie; Saito, Taiju; Takeda, Takahiro; Fujimoto, Takafumi; Takagi, Misae; Arai, Katsutoshi; Yamaha, Etsuto

    2012-10-01

    The presence of germ cells in the early gonad is important for sexual fate determination and gonadal development in vertebrates. Recent studies in zebrafish and medaka have shown that a lack of germ cells in the early gonad induces sex reversal in favor of a male phenotype. However, it is uncertain whether the gonadal somatic cells or the germ cells are predominant in determining gonadal fate in other vertebrate. Here, we investigated the role of germ cells in gonadal differentiation in goldfish, a gonochoristic species that possesses an XX-XY genetic sex determination system. The primordial germ cells (PGCs) of the fish were eliminated during embryogenesis by injection of a morpholino oligonucleotide against the dead end gene. Fish without germ cells showed two types of gonadal morphology: one with an ovarian cavity; the other with seminiferous tubules. Next, we tested whether function could be restored to these empty gonads by transplantation of a single PGC into each embryo, and also determined the gonadal sex of the resulting germline chimeras. Transplantation of a single GFP-labeled PGC successfully produced a germline chimera in 42.7% of the embryos. Some of the adult germline chimeras had a developed gonad on one side that contained donor derived germ cells, while the contralateral gonad lacked any early germ cell stages. Female germline chimeras possessed a normal ovary and a germ-cell free ovary-like structure on the contralateral side; this structure was similar to those seen in female morphants. Male germline chimeras possessed a testis and a contralateral empty testis that contained some sperm in the tubular lumens. Analysis of aromatase, foxl2 and amh expression in gonads of morphants and germline chimeras suggested that somatic transdifferentiation did not occur. The offspring of fertile germline chimeras all had the donor-derived phenotype, indicating that germline replacement had occurred and that the transplanted PGC had rescued both female and

  19. Germ line, stem cells, and epigenetic reprogramming.

    PubMed

    Surani, M A; Durcova-Hills, G; Hajkova, P; Hayashi, K; Tee, W W

    2008-01-01

    The germ cell lineage has the unique attribute of generating the totipotent state. Development of blastocysts from the totipotent zygote results in the establishment of pluripotent primitive ectoderm cells in the inner cell mass of blastocysts, which subsequently develop into epiblast cells in postimplantation embryos. The germ cell lineage in mice originates from these pluripotent epiblast cells of postimplantation embryos in response to specific signals. Pluripotent stem cells and unipotent germ cells share some fundamental properties despite significant phenotypic differences between them. Additionally, early primordial germ cells can be induced to undergo dedifferentiation into pluripotent embryonic germ cells. Investigations on the relationship between germ cells and pluripotent stem cells may further elucidate the nature of the pluripotent state. Furthermore, comprehensive epigenetic reprogramming of the genome in early germ cells, including extensive erasure of epigenetic modifications, is a critical step toward establishment of totipotency. The mechanisms involved may be relevant for gaining insight into events that lead to reprogramming of somatic cells into pluripotent stem cells.

  20. Bovine ovarian stem cells differentiate into germ cells and oocyte-like structures after culture in vitro.

    PubMed

    de Souza, G B; Costa, Jjn; da Cunha, E V; Passos, Jrs; Ribeiro, R P; Saraiva, Mva; van den Hurk, R; Silva, Jrv

    2017-04-01

    Stem cells have been isolated from ovaries, and their ability to differentiate into oocytes in vitro has been demonstrated for mice and human, but not for bovine species. The aims of this study were to isolate germline stem cells from bovine ovaries and to evaluate the effects of bone morphogenetic proteins (BMPs) 2 and 4, and follicular fluid on the differentiation of these stem cells into oocyte-like structures. The ovarian stem cells were isolated and cultured in α-MEM(+) supplemented with BMP2, BMP4 or follicular fluid. On days 0 and 14, cells were evaluated for their morphological appearance, viability, expression of alkaline phosphatase and for markers of germ cell formation (VASA and DAZL) and oocyte development (GDF9, ZPA and SCP3) by qPCR. Levels of mRNA were analysed using ANOVA and Bonferroni test (p < .05). The results showed that at day 0, ovarian stem cells expressed specific markers of pluripotency (OCT4, SOX). In addition, these cells were positive for alkaline phosphatase, which is a marker commonly used to identify primordial germ cells (PGCs). After the period of differentiation, cells had morphological features that resemble PGCs and oocyte-like cells (OLCs). An increase, ranging from five to 14 times, in the expression of VASA was observed in cells cultured in medium supplemented with BMPs and follicular fluid, while the increase in DAZL expression ranged from four to six times. In addition, OLCs had an increase in expression of mRNAs for GDF9, ZPA and SCP3 that ranged from two to eight times. In conclusion, OLCs can be differentiated in vitro from ovarian stem cells and BMPs and follicular fluid are effective in stimulating the expression of mRNAs for germ cell and oocyte markers. © 2016 Blackwell Verlag GmbH.

  1. In vivo epigenomic profiling of germ cells reveals germ cell molecular signatures.

    PubMed

    Ng, Jia-Hui; Kumar, Vibhor; Muratani, Masafumi; Kraus, Petra; Yeo, Jia-Chi; Yaw, Lai-Ping; Xue, Kun; Lufkin, Thomas; Prabhakar, Shyam; Ng, Huck-Hui

    2013-02-11

    The limited number of in vivo germ cells poses an impediment to genome-wide studies. Here, we applied a small-scale chromatin immunoprecipitation sequencing (ChIP-seq) method on purified mouse fetal germ cells to generate genome-wide maps of four histone modifications (H3K4me3, H3K27me3, H3K27ac, and H2BK20ac). Comparison of active chromatin state between somatic, embryonic stem, and germ cells revealed promoters and enhancers needed for stem cell maintenance and germ cell development. We found the nuclear receptor Nr5a2 motif to be enriched at a subset of germ cell cis-regulatory regions, and our results implicate Nr5a2 in germ cell biology. Interestingly, in germ cells, the H3K27me3 histone modification occurs more frequently at regions that are enriched for retrotransposons and MHC genes, indicating that these loci are specifically silenced in germ cells. Together, our study provides genome-wide histone modification maps of in vivo germ cells and reveals the molecular chromatin signatures of germ cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Germ cell specification and regeneration in planarians.

    PubMed

    Newmark, P A; Wang, Y; Chong, T

    2008-01-01

    In metazoans, two apparently distinct mechanisms specify germ cell fate: Determinate specification (observed in animals including Drosophila, Caenorhabditis elegans, zebra fish, and Xenopus) uses cytoplasmic factors localized to specific regions of the egg, whereas epigenetic specification (observed in many basal metazoans, urodeles, and mammals) involves inductive interactions between cells. Much of our understanding of germ cell specification has emerged from studies of model organisms displaying determinate specification. In contrast, our understanding of epigenetic/inductive specification is less advanced and would benefit from studies of additional organisms. Freshwater planarians--widely known for their remarkable powers of regeneration--are well suited for studying the mechanisms by which germ cells can be induced. Classic experiments showed that planarians can regenerate germ cells from body fragments entirely lacking reproductive structures, suggesting that planarian germ cells could be specified by inductive signals. Furthermore, the availability of the genome sequence of the planarian Schmidtea mediterranea, coupled with the animal's susceptibility to systemic RNA interference (RNAi), facilitates functional genomic analyses of germ cell development and regeneration. Here, we describe recent progress in studies of planarian germ cells and frame some of the critical unresolved questions for future work.

  3. The hedgehog Pathway Gene shifted Functions together with the hmgcr-Dependent Isoprenoid Biosynthetic Pathway to Orchestrate Germ Cell Migration

    PubMed Central

    Deshpande, Girish; Zhou, Keren; Wan, Joy Y.; Friedrich, Jana; Jourjine, Nicholas; Smith, Daniel; Schedl, Paul

    2013-01-01

    The Drosophila embryonic gonad is assembled from two distinct cell types, the Primordial Germ Cells (PGCs) and the Somatic Gonadal Precursor cells (SGPs). The PGCs form at the posterior of blastoderm stage embryos and are subsequently carried inside the embryo during gastrulation. To reach the SGPs, the PGCs must traverse the midgut wall and then migrate through the mesoderm. A combination of local repulsive cues and attractive signals emanating from the SGPs guide migration. We have investigated the role of the hedgehog (hh) pathway gene shifted (shf) in directing PGC migration. shf encodes a secreted protein that facilitates the long distance transmission of Hh through the proteoglycan matrix after it is released from basolateral membranes of Hh expressing cells in the wing imaginal disc. shf is expressed in the gonadal mesoderm, and loss- and gain-of-function experiments demonstrate that it is required for PGC migration. Previous studies have established that the hmgcr-dependent isoprenoid biosynthetic pathway plays a pivotal role in generating the PGC attractant both by the SGPs and by other tissues when hmgcr is ectopically expressed. We show that production of this PGC attractant depends upon shf as well as a second hh pathway gene gγ1. Further linking the PGC attractant to Hh, we present evidence indicating that ectopic expression of hmgcr in the nervous system promotes the release/transmission of the Hh ligand from these cells into and through the underlying mesodermal cell layer, where Hh can contact migrating PGCs. Finally, potentiation of Hh by hmgcr appears to depend upon cholesterol modification. PMID:24068944

  4. Germ Cell Differentiation from Pluripotent Cells

    PubMed Central

    Medrano, Jose V.; Pera, Renee A. Reijo; Simón, Carlos

    2014-01-01

    Infertility is a medical condition with an increasing impact in Western societies with causes linked to toxins, genetics, and aging (primarily delay of motherhood). Within the different pathologies that can lead to infertility, poor quality or reduced quantity of gametes plays an important role. Gamete donation and therefore demand on donated sperm and eggs in fertility clinics is increasing. It is hoped that a better understanding of the conditions related to poor gamete quality may allow scientists to design rational treatments. However, to date, relatively little is known about human germ cell development in large part due to the inaccessibility of human development to molecular genetic analysis. It is hoped that pluripotent human embryonic stem cells and induced pluripotent stem cells may provide an accessible in vitro model to study germline development; these cells are able to differentiate to cells of all three primary embryonic germ layers, as well as to germ cells in vitro. We review the state of the art in germline differentiation from pluripotent stem cells. PMID:23329632

  5. Metabolic Reprogramming, Autophagy, and Reactive Oxygen Species Are Necessary for Primordial Germ Cell Reprogramming into Pluripotency

    PubMed Central

    Sainz de la Maza, D.; Moratilla, A.; Aparicio, V.; Lorca, C.; Alcaina, Y.; Martín, D.

    2017-01-01

    Cellular reprogramming is accompanied by a metabolic shift from oxidative phosphorylation (OXPHOS) toward glycolysis. Previous results from our laboratory showed that hypoxia alone is able to reprogram primordial germ cells (PGCs) into pluripotency and that this action is mediated by hypoxia-inducible factor 1 (HIF1). As HIF1 exerts a myriad of actions by upregulating several hundred genes, to ascertain whether the metabolic switch toward glycolysis is solely responsible for reprogramming, PGCs were cultured in the presence of a pyruvate kinase M2 isoform (PKM2) activator, or glycolysis was promoted by manipulating PPARγ. Conversely, OXPHOS was stimulated by inhibiting PDK1 activity in normoxic or in hypoxic conditions. Inhibition or promotion of autophagy and reactive oxygen species (ROS) production was performed to ascertain their role in cell reprogramming. Our results show that a metabolic shift toward glycolysis, autophagy, and mitochondrial inactivation and an early rise in ROS levels are necessary for PGC reprogramming. All of these processes are governed by HIF1/HIF2 balance and strict intermediate Oct4 levels. Histone acetylation plays a role in reprogramming and is observed under all reprogramming conditions. The pluripotent cells thus generated were unable to self-renew, probably due to insufficient Blimp1 downregulation and a lack of Klf4 and cMyc expression. PMID:28757909

  6. Sex determination in mammalian germ cells

    PubMed Central

    Spiller, Cassy M; Bowles, Josephine

    2015-01-01

    Germ cells are the precursors of the sperm and oocytes and hence are critical for survival of the species. In mammals, they are specified during fetal life, migrate to the developing gonads and then undergo a critical period during which they are instructed, by the soma, to adopt the appropriate sexual fate. In a fetal ovary, germ cells enter meiosis and commit to oogenesis, whereas in a fetal testis, they avoid entry into meiosis and instead undergo mitotic arrest and mature toward spermatogenesis. Here, we discuss what we know so far about the regulation of sex-specific differentiation of germ cells, considering extrinsic molecular cues produced by somatic cells, as well as critical intrinsic changes within the germ cells. This review focuses almost exclusively on our understanding of these events in the mouse model. PMID:25791730

  7. Sex determination in mammalian germ cells.

    PubMed

    Spiller, Cassy M; Bowles, Josephine

    2015-01-01

    Germ cells are the precursors of the sperm and oocytes and hence are critical for survival of the species. In mammals, they are specified during fetal life, migrate to the developing gonads and then undergo a critical period during which they are instructed, by the soma, to adopt the appropriate sexual fate. In a fetal ovary, germ cells enter meiosis and commit to oogenesis, whereas in a fetal testis, they avoid entry into meiosis and instead undergo mitotic arrest and mature toward spermatogenesis. Here, we discuss what we know so far about the regulation of sex-specific differentiation of germ cells, considering extrinsic molecular cues produced by somatic cells, as well as critical intrinsic changes within the germ cells. This review focuses almost exclusively on our understanding of these events in the mouse model.

  8. Regulation of germ cell function by SUMOylation

    PubMed Central

    Rodriguez, Amanda; Pangas, Stephanie A.

    2015-01-01

    Oogenesis and spermatogenesis are tightly regulated complex processes that are critical for fertility function. Germ cells undergo meiosis to generate haploid cells necessary for reproduction. Errors in meiosis, including the generation of chromosomal abnormalities, can result in reproductive defects and infertility. Meiotic proteins are regulated by post-translational modifications including SUMOylation, the covalent attachment of small ubiquitin-like modifier (SUMO) proteins. Here, we review the role of SUMO proteins in controlling germ cell development and maturation based on recent findings from mouse models. Several studies have characterized the localization of SUMO proteins in male and female germ cells. However, a deeper understanding of how SUMOylation regulates proteins with essential roles in oogenesis and spermatogenesis will provide useful insight into the underlying mechanisms of germ cell development and fertility. PMID:26374733

  9. Comparative metabolic pathway analysis with special reference to nucleotide metabolism-related genes in chicken primordial germ cells.

    PubMed

    Rengaraj, Deivendran; Lee, Bo Ram; Jang, Hyun-Jun; Kim, Young Min; Han, Jae Yong

    2013-01-01

    Metabolism provides energy and nutrients required for the cellular growth, maintenance, and reproduction. When compared with genomics and proteomics, metabolism studies provide novel findings in terms of cellular functions. In this study, we examined significant and differentially expressed genes in primordial germ cells (PGCs), gonadal stromal cells, and chicken embryonic fibroblasts compared with blastoderms using microarray. All upregulated genes (1001, 1118, and 974, respectively) and downregulated genes (504, 627, and 1317, respectively) in three test samples were categorized into functional groups according to gene ontology. Then all selected genes were tested to examine their involvement in metabolic pathways through Kyoto Encyclopedia of Genes and Genomes pathway database using overrepresentation analysis. In our results, most of the upregulated and downregulated genes were involved in at least one subcategory of seven major metabolic pathways. The main objective of this study is to compare the PGC expressed genes and their metabolic pathways with blastoderms, gonadal stromal cells, and chicken embryonic fibroblasts. Among the genes involved in metabolic pathways, a higher number of PGC upregulated genes were identified in retinol metabolism, and a higher number of PGC downregulated genes were identified in sphingolipid metabolism. In terms of the fold change, acyl-CoA synthetase medium-chain family member 3 (ACSM3), which is involved in butanoate metabolism, and N-acetyltransferase, pineal gland isozyme NAT-10 (PNAT10), which is involved in energy metabolism, showed higher expression in PGCs. To validate these gene changes, the expression of 12 nucleotide metabolism-related genes in chicken PGCs was examined by real-time polymerase chain reaction. The results of this study provide new information on the expression of genes associated with metabolism function of PGCs and will facilitate more basic research on animal PGC differentiation and function.

  10. Transport of germ plasm on astral microtubules directs germ cell development in Drosophila

    PubMed Central

    Lerit, Dorothy A.; Gavis, Elizabeth R.

    2011-01-01

    Summary Background In many organisms, germ cells are segregated from the soma through the inheritance of the specialized germ plasm, which contains mRNAs and proteins that specify germ cell fate and promote germline development. Whereas germ plasm assembly has been well characterized, mechanisms mediating germ plasm inheritance are poorly understood. In the Drosophila embryo, germ plasm is anchored to the posterior cortex and nuclei that migrate into this region give rise to the germ cell progenitors, or pole cells. How the germ plasm interacts with these nuclei for pole cell induction and is selectively incorporated into the forming pole cells is not known. Results Live imaging of two conserved germ plasm components, nanos mRNA and Vasa protein, revealed that germ plasm segregation is a dynamic process involving active transport of germ plasm RNA-protein complexes coordinated with nuclear migration. We show that centrosomes accompanying posterior nuclei induce release of germ plasm from the cortex and recruit these components by dynein-dependent transport on centrosome-nucleated microtubules. As nuclei divide, continued transport on astral microtubules partitions germ plasm to daughter nuclei, leading to its segregation into pole cells. Disruption of these transport events prevents incorporation of germ plasm into pole cells and impairs germ cell development. Conclusions Our results indicate that active transport of germ plasm is essential for its inheritance and ensures the production of a discrete population of germ cell progenitors endowed with requisite factors for germline development. Transport on astral microtubules may provide a general mechanism for the effective segregation of cell fate determinants. PMID:21376599

  11. Dissecting Germ Cell Metabolism through Network Modeling.

    PubMed

    Whitmore, Leanne S; Ye, Ping

    2015-01-01

    Metabolic pathways are increasingly postulated to be vital in programming cell fate, including stemness, differentiation, proliferation, and apoptosis. The commitment to meiosis is a critical fate decision for mammalian germ cells, and requires a metabolic derivative of vitamin A, retinoic acid (RA). Recent evidence showed that a pulse of RA is generated in the testis of male mice thereby triggering meiotic commitment. However, enzymes and reactions that regulate this RA pulse have yet to be identified. We developed a mouse germ cell-specific metabolic network with a curated vitamin A pathway. Using this network, we implemented flux balance analysis throughout the initial wave of spermatogenesis to elucidate important reactions and enzymes for the generation and degradation of RA. Our results indicate that primary RA sources in the germ cell include RA import from the extracellular region, release of RA from binding proteins, and metabolism of retinal to RA. Further, in silico knockouts of genes and reactions in the vitamin A pathway predict that deletion of Lipe, hormone-sensitive lipase, disrupts the RA pulse thereby causing spermatogenic defects. Examination of other metabolic pathways reveals that the citric acid cycle is the most active pathway. In addition, we discover that fatty acid synthesis/oxidation are the primary energy sources in the germ cell. In summary, this study predicts enzymes, reactions, and pathways important for germ cell commitment to meiosis. These findings enhance our understanding of the metabolic control of germ cell differentiation and will help guide future experiments to improve reproductive health.

  12. Attraction rules: germ cell migration in zebrafish.

    PubMed

    Raz, Erez; Reichman-Fried, Michal

    2006-08-01

    The migration of zebrafish primordial germ cell towards the region where the gonad develops is guided by the chemokine SDF-1a. Recent studies show that soon after their specification, the cells undergo a series of morphological alterations before they become motile and are able to respond to attractive cues. As migratory cells, primordial germ cells move towards their target while correcting their path upon exiting a cyclic phase in which morphological cell polarity is lost. In the following stages, the cells gather at specific locations and move as cell clusters towards their final target. In all of these stages, zebrafish germ cells respond as individual cells to alterations in the shape of the sdf-1a expression domain, by directed migration towards their target - the position where the gonad develops.

  13. Surgery for germ cell tumors.

    PubMed

    Sagae, S; Kudo, R

    2000-01-01

    We performed a review of the current modalities of surgical treatment of malignant ovarian germ cell tumors by clinical stages and histological types. Stage IA dysgerminoma is performed with a unilateral salpingo-oophorectomy (USO) without chemotherapy. However, for Stage IB or IC patients with dysgerminoma, USO plus chemotherapy as a primary treatment may or may not be followed with a second-look operation (SLO). For non-dysgerminomas, USO is indicated only for Stage IA immature teratoma grade 1. The treatment for Stage IA immature teratoma grade 2 or 3 and other histological types is USO plus chemotherapy. Patients with Stage IB, IC or higher with non-dysgerminoma are treated with USO plus chemotherapy or USO with contralateral partial ovariectomy plus chemotherapy. For patients who require non-conservative surgery, a total abdominal hysterectomy (TAH) and a bilateral salpingo-oophorectomy (BSO) plus chemotherapy are performed. For patients with Stage II of all histological types, conservative surgery consists of USO and a cytoreductive operation plus chemotherapy, followed by SLO or a second cytoreductive operation. For non-conservative surgery, TAH+BSO with or without a cytoreductive operation plus chemotherapy is followed by SLO. Conservative surgery for patients with Stage III and IV is USO and a cytoreductive operation plus chemotherapy followed by a second cytoreductive operation. Non-conservative surgery is TAH+BSO with a cytoreductive operation plus chemotherapy, followed by SLO or a second cytoreductive operation. However, primary or secondary cytoreductive surgery with or without lymphadenectomy and SLO are still controversial in terms of improving patient survival. Copyright 2000 Wiley-Liss, Inc.

  14. Emerging methods to generate artificial germ cells from stem cells.

    PubMed

    Zeng, Fanhui; Huang, Fajun; Guo, Jingjing; Hu, Xingchang; Liu, Changbai; Wang, Hu

    2015-04-01

    Germ cells are responsible for the transmission of genetic and epigenetic information across generations. At present, the number of infertile couples is increasing worldwide; these infertility problems can be traced to environmental pollutions, infectious diseases, cancer, psychological or work-related stress, and other factors, such as lifestyle and genetics. Notably, lack of germ cells and germ cell loss present real obstacles in infertility treatment. Recent research aimed at producing gametes through artificial germ cell generation from stem cells may offer great hope for affected couples to treat infertility in the future. Therefore, this rapidly emerging area of artificial germ cell generation from nongermline cells has gained considerable attention from basic and clinical research in the fields of stem cell biology, developmental biology, and reproductive biology. Here, we review the state of the art in artificial germ cell generation. © 2015 by the Society for the Study of Reproduction, Inc.

  15. Retinoic acid induces differentiation of buffalo (Bubalus bubalis) embryonic stem cells into germ cells.

    PubMed

    Shah, Syed Mohmad; Singla, Suresh Kumar; Palta, Prabhat; Manik, Radhey Sham; Chauhan, Manmohan Singh

    2017-10-05

    Development of precise and reproducible culture system for in vitro differentiation of embryonic stem (ES) cells into germ cells counts as a major leap forward for understanding not only the remarkable process of gametogenesis, otherwise obscured by limited availability of precursor primordial germ cells (PGCs), but in finally treating the catastrophic infertility. Taking into account the significant role of retinoic acid (RA) during in vivo gametogenesis, we designed the present study to investigate the effects of its stimulation on directing the differentiation of ES cells into germ cells. The effects of RA were analyzed across dose-and-time upon various stages of gametogenesis like PGC induction, meiosis initiation and completion, haploid cell formation and development of the final gamete (oocyte and spermatozoa). Out of the series of RA doses (2, 4, 8, 16, 20 and 30μM), 16μM RA for 8day culture interval was found to induce highest expression of PGC- and meiosis-associated genes like DAZL, VASA, SYCP3, MLH1, TNP1/2 and PRM2, while mature germ cell genes like BOULE and TEKT1 (Spermatocyte markers), GDF9 and ZP2 (Oocyte markers) showed higher expression at 2μM RA dose, suggesting functional concentration-gradient of RA activity. Immunocytochemistry revealed expression of germ lineage-specific markers like: c-KIT, DAZL and VASA (PGC-markers); SYCP3, MLH1 and PROTAMINE1 (Meiotic-markers); ACROSIN and HAPRIN (Spermatocyte-markers); and GDF9 and ZP4 (Oocyte-markers) in optimally differentiated embryoid bodies (EBs) and adherent cultures. We observed significantly reduced (p<0.05) concentration of 5-methyl-2-deoxycytidine in RA-differentiated EBs which is suggestive of the occurrence of methylation erasure. FACS analysis of optimally differentiated cultures detected 3.07% haploid cell population, indicating completion of meiosis. Oocyte-like structures (OLS) were obtained in adherent differentiated cultures. They had a big nucleus and a zona pellucida (ZP4) coat

  16. Retinoic acid induces differentiation of buffalo (Bubalus bubalis) embryonic stem cells into germ cells.

    PubMed

    Shah, Syed Mohmad; Singla, Suresh Kumar; Palta, Prabhat; Manik, Radhey Sham; Chauhan, Manmohan Singh

    2017-08-30

    Development of precise and reproducible culture system for in vitro differentiation of embryonic stem (ES) cells into germ cells counts as a major leap forward for understanding not only the remarkable process of gametogenesis, otherwise obscured by limited availability of precursor primordial germ cells (PGCs), but in finally treating the catastrophic infertility. Taking into account the significant role of retinoic acid (RA) during in vivo gametogenesis, we designed the present study to investigate the effects of its stimulation on directing the differentiation of ES cells into germ cells. The effects of RA were analyzed across dose-and-time upon various stages of gametogenesis like PGC induction, meiosis initiation and completion, haploid cell formation and development of the final gamete (oocyte and spermatozoa). Out of the series of RA doses (2, 4, 8, 16, 20 and 30μM), 16μM RA for 8day culture interval was found to induce highest expression of PGC- and meiosis-associated genes like DAZL, VASA, SYCP3, MLH1, TNP1/2 and PRM2, while mature germ cell genes like BOULE and TEKT1 (Spermatocyte markers), GDF9 and ZP2 (Oocyte markers) showed higher expression at 2μM RA dose, suggesting functional concentration-gradient of RA activity. Immunocytochemistry revealed expression of germ lineage-specific markers like: c-KIT, DAZL and VASA (PGC-markers); SYCP3, MLH1 and PROTAMINE1 (Meiotic-markers); ACROSIN and HAPRIN (Spermatocyte-markers); and GDF9 and ZP4 (Oocyte-markers) in optimally differentiated embryoid bodies (EBs) and adherent cultures. We observed significantly reduced (p<0.05) concentration of 5-methyl-2-deoxycytidine in RA-differentiated EBs which is suggestive of the occurrence of methylation erasure. FACS analysis of optimally differentiated cultures detected 3.07% haploid cell population, indicating completion of meiosis. Oocyte-like structures (OLS) were obtained in adherent differentiated cultures. They had a big nucleus and a zona pellucida (ZP4) coat

  17. [Germ cell membrane lipids in spermatogenesis].

    PubMed

    Wang, Ting; Shi, Xiao; Quan, Song

    2016-05-01

    Spermatogenesis is a complex developmental process in which a diploid progenitor germ cell transforms into highly specialized spermatozoa. During spermatogenesis, membrane remodeling takes place, and cell membrane permeability and liquidity undergo phase-specific changes, which are all associated with the alteration of membrane lipids. Lipids are important components of the germ cell membrane, whose volume and ratio fluctuate in different phases of spermatogenesis. Abnormal lipid metabolism can cause spermatogenic dysfunction and consequently male infertility. Germ cell membrane lipids are mainly composed of cholesterol, phospholipids and glycolipids, which play critical roles in cell adhesion and signal transduction during spermatogenesis. An insight into the correlation of membrane lipids with spermatogenesis helps us to better understand the mechanisms of spermatogenesis and provide new approaches to the diagnosis and treatment of male infertility.

  18. Genomic Landscape of Developing Male Germ Cells

    PubMed Central

    Lee, Tin-Lap; Pang, Alan Lap-Yin; Rennert, Owen M.; Chan, Wai-Yee

    2010-01-01

    Spermatogenesis is a highly orchestrated developmental process by which spermatogonia develop into mature spermatozoa. This process involves many testis- or male germ cell-specific gene products whose expressions are strictly regulated. In the past decade the advent of high-throughput gene expression analytical techniques has made functional genomic studies of this process, particularly in model animals such as mice and rats, feasible and practical. These studies have just begun to reveal the complexity of the genomic landscape of the developing male germ cells. Over 50% of the mouse and rat genome are expressed during testicular development. Among transcripts present in germ cells, 40% – 60% are uncharacterized. A number of genes, and consequently their associated biological pathways, are differentially expressed at different stages of spermatogenesis. Developing male germ cells present a rich repertoire of genetic processes. Tissue-specific as well as spermatogenesis stage-specific alternative splicing of genes exemplifies the complexity of genome expression. In addition to this layer of control, discoveries of abundant presence of antisense transcripts, expressed psuedogenes, non-coding RNAs (ncRNA) including long ncRNAs, microRNAs (miRNAs) and Piwi-interacting RNAs (piRNAs), and retrogenes all point to the presence of multiple layers of expression and functional regulation in male germ cells. It is anticipated that application of systems biology approaches will further our understanding of the regulatory mechanism of spermatogenesis.† PMID:19306351

  19. Cadmium increases human fetal germ cell apoptosis.

    PubMed

    Angenard, Gaëlle; Muczynski, Vincent; Coffigny, Hervé; Pairault, Catherine; Duquenne, Clotilde; Frydman, René; Habert, René; Rouiller-Fabre, Virginie; Livera, Gabriel

    2010-03-01

    Cadmium (Cd) is a common environmental pollutant and a major constituent of tobacco smoke. Adverse effects of this heavy metal on reproductive function have been identified in adults; however, no studies have examined its effects on human reproductive organs during development. Using our previously developed organ culture system, we investigated the effects of cadmium chloride on human gonads at the beginning of fetal life, a critical stage in the development of reproductive function. Human fetal gonads were recovered during the first trimester (711 weeks postconception) and cultured with or without Cd. We used different concentrations of Cd and compared results with those obtained with mouse fetal gonads at similar stages. Cd, at concentrations as low as 1 microM, significantly decreased the germ cell density in human fetal ovaries. This correlated with an increase in germ cell apoptosis, but there was no effect on proliferation. Similarly, in the human fetal testis, Cd (1 microM) reduced germ cell number without affecting testosterone secretion. In mouse fetal gonads, Cd increased only female germ cell apoptosis. This is the first experimental demonstration that Cd, at low concentrations, alters the survival of male and female germ cells in humans. Considering data demonstrating extensive human exposure, we believe that current environmental levels of Cd could be deleterious to early gametogenesis.

  20. Paediatric extracranial germ-cell tumours.

    PubMed

    Shaikh, Furqan; Murray, Matthew J; Amatruda, James F; Coleman, Nicholas; Nicholson, James C; Hale, Juliet P; Pashankar, Farzana; Stoneham, Sara J; Poynter, Jenny N; Olson, Thomas A; Billmire, Deborah F; Stark, Daniel; Rodriguez-Galindo, Carlos; Frazier, A Lindsay

    2016-04-01

    Management of paediatric extracranial germ-cell tumours carries a unique set of challenges. Germ-cell tumours are a heterogeneous group of neoplasms that present across a wide age range and vary in site, histology, and clinical behaviour. Patients with germ-cell tumours are managed by a diverse array of specialists. Thus, staging, risk stratification, and treatment approaches for germ-cell tumours have evolved disparately along several trajectories. Paediatric germ-cell tumours differ from the adolescent and adult disease in many ways, leading to complexities in applying age-appropriate, evidence-based care. Suboptimal outcomes remain for several groups of patients, including adolescents, and patients with extragonadal tumours, high tumour markers at diagnosis, or platinum-resistant disease. Survivors have significant long-term toxicities. The challenge moving forward will be to translate new insights from molecular studies and collaborative clinical data into improved patient outcomes. Future trials will be characterised by improved risk-stratification systems, biomarkers for response and toxic effects, rational reduction of therapy for low-risk patients and novel approaches for poor-risk patients, and improved international collaboration across paediatric and adult cooperative research groups. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Identification and Migration of Primordial Germ Cells in Atlantic Salmon, Salmo salar: Characterization of Vasa, Dead End, and Lymphocyte Antigen 75 Genes

    PubMed Central

    Nagasawa, Kazue; Fernandes, Jorge MO; Yoshizaki, Goro; Miwa, Misako; Babiak, Igor

    2013-01-01

    No information exists on the identification of primordial germ cells (PGCs) in the super-order Protacanthopterygii, which includes the Salmonidae family and Atlantic salmon (Salmo salar L.), one of the most commercially important aquatic animals worldwide. In order to identify salmon PGCs, we cloned the full-length cDNA of vasa, dead end (dnd), and lymphocyte antigen 75 (ly75/CD205) genes as germ cell marker candidates, and analyzed their expression patterns in both adult and embryonic stages of Atlantic salmon. Semi-quantitative RT-PCR results showed that salmon vasa and dnd were specifically expressed in testis and ovary, and vasa, dnd, and ly75 mRNA were maternally deposited in the egg. vasa mRNA was consistently detected throughout embryogenesis while dnd and ly75 mRNA were gradually degraded during cleavages. In situ analysis revealed the localization of vasa and dnd mRNA and Ly75 protein in PGCs of hatched larvae. Whole-mount in situ hybridization detected vasa mRNA during embryogenesis, showing a distribution pattern somewhat different to that of zebrafish; specifically, at mid-blastula stage, vasa-expressing cells were randomly distributed at the central part of blastodisc, and then they migrated to the presumptive region of embryonic shield. Therefore, the typical vasa localization pattern of four clusters during blastulation, as found in zebrafish, was not present in Atlantic salmon. In addition, salmon PGCs could be specifically labeled with a green fluorescence protein (GFP) using gfp-rt-vasa 3′-UTR RNA microinjection for further applications. These findings may assist in understanding PGC development not only in Atlantic salmon but also in other salmonids. PMID:23239145

  2. Surgery and Combination Chemotherapy in Treating Children With Extracranial Germ Cell Tumors

    ClinicalTrials.gov

    2016-05-06

    Childhood Embryonal Tumor; Childhood Extracranial Germ Cell Tumor; Childhood Extragonadal Germ Cell Tumor; Childhood Malignant Ovarian Germ Cell Tumor; Childhood Malignant Testicular Germ Cell Tumor; Childhood Teratoma; Ovarian Embryonal Carcinoma; Ovarian Yolk Sac Tumor; Stage II Malignant Testicular Germ Cell Tumor; Stage IIA Ovarian Germ Cell Tumor; Stage IIB Ovarian Germ Cell Tumor; Stage IIC Ovarian Germ Cell Tumor; Stage III Malignant Testicular Germ Cell Tumor; Stage IIIA Ovarian Germ Cell Tumor; Stage IIIB Ovarian Germ Cell Tumor; Stage IIIC Ovarian Germ Cell Tumor; Testicular Choriocarcinoma and Yolk Sac Tumor; Testicular Embryonal Carcinoma

  3. The neural stem cell lineage reveals novel relationships among spermatogonial germ stem cells and other pluripotent stem cells.

    PubMed

    Teichert, Anouk-Martine; Pereira, Schreiber; Coles, Brenda; Chaddah, Radha; Runciman, Susan; Brokhman, Irina; van der Kooy, Derek

    2014-04-01

    The embryonic stem cell (ESC) derived from the inner cell mass is viewed as the core pluripotent cell (PC) type from which all other cell types emanate. This familiar perspective derives from an embryological time line in which PCs are ordered according to their time of appearance. However, this schema does not take into account their potential for interconversion, thereby excluding this critical quality of PCs. The persistence of bona fide pluripotent adult stem cells has garnered increasing attention in recent years. Adult pluripotent spermatogonial germ stem cells (aSGSCs) arise from primordial germ cells (pGCs) that emerge from the epiblast during gastrulation. Adult definitive neural stem cells (dNSCs) arise clonally from pluripotent embryonic primitive neural stem cells (pNSCs), which can also be derived clonally from ESCs. To test for stem cell-type convertibility, we employed differentiation in the clonal lineage from ESCs to pNSCs to dNSCs, and revealed the relationships and lineage positioning among various PC populations, including spermatogonial germ cells (aSGSCs), epiblast-derived stem cells (Epi-SCs) and the bFGF, Activin, and BIO-derived stem cell (FAB-SC). Adult, murine aSGSCs assumed a 'pseudo-ESC' state in vitro, and then differentiated into dNSCs, but not pNSCs. Similarly, Epi-SCs and FAB-SCs only gave rise to dNSCs and not to pNSCs. The results of these experiments suggest a new pluripotency lineage model describing the relationship(s) among PCs that better reflects the transitions between these cell types in vitro.

  4. Intracardiac metastasis from germ cell testicular tumor.

    PubMed

    Jonjev, Z S; Rajić, J; Majin, M; Donat, D

    2012-09-01

    Intracardiac metastases of germ cell testicular tumors are not commonly seen in clinical practice. The clinical presentation of right-sided heart metastases ranges widely. Depending upon its size and intracardiac location, it could be highly symptomatic, leading to a congestive heart failure, pulmonary embolism, and death, or completely asymptomatic. Improved imaging techniques and treatment strategies demonstrate that right-sided heart metastasis should be considered a potentially dangerous but treatable disease. Presented is the case of a 24-year-old man with a testicular nonseminomatous germ cell tumor, which after metastasizing in the right atrium differentiated into a teratoma and resulted in an inflow obstruction of the right ventricle.

  5. Childhood Central Nervous System Germ Cell Tumors Treatment

    MedlinePlus

    ... Ependymoma Treatment Research Childhood Central Nervous System Germ Cell Tumors Treatment (PDQ®)–Patient Version General Information About Childhood Central Nervous System (CNS) Germ Cell Tumors Go to Health Professional Version Key Points ...

  6. Treatment Options By Stage (Ovarian Germ Cell Tumors)

    MedlinePlus

    ... Tube, & Primary Peritoneal Cancer Screening Research Ovarian Germ Cell Tumors Treatment (PDQ®)–Patient Version General Information About Ovarian Germ Cell Tumors Go to Health Professional Version Key Points ...

  7. Multispecies Purification of Testicular Germ Cells.

    PubMed

    Lima, Ana C; Jung, Min; Rusch, Jannette; Usmani, Abul; Lopes, Alexandra; Conrad, Donald F

    2016-08-24

    Advanced methods of cellular purification are required to apply genome technology to the study of spermatogenesis. One approach, based on flow cytometry of murine testicular cells stained with Hoechst-33342 (Ho-FACS), has been extensively optimized and currently allows the isolation of 9 germ cell types. This staining technique is straightforward to implement, highly effective at purifying specific germ cell types and yields sufficient cell numbers for high throughput studies. Ho-FACS is a technique that does not require species-specific markers, but whose applicability to other species is largely unexplored. We hypothesized that, due to the similar cell physiology of spermatogenesis across mammals, Ho-FACS could be used to produce highly purified subpopulations of germ cells in mammals other than mouse. To test this hypothesis, we applied Ho-FACS to 4 mammalian species that are widely used in testis research - Rattus norvegicus, Cavia porcellus, Canis familiaris and Sus scrofa domesticus We successfully isolated 4 germ cell populations from these species with average purity of 79% for spermatocytes, and 90% for spermatids and 66% for spermatogonia. Additionally, we compare the performance of mechanical and chemical dissociation for each species, and propose an optimized gating strategy to better discriminate round and elongating spermatids in the mouse, which can potentially be applied to other species. Our work indicates that spermatogenesis may be uniquely accessible among mammalian developmental systems, as a single set of reagents may be sufficient to isolate germ cell populations from many different mammalian species, opening new avenues in the fields of development and male reproductive biology.

  8. Multispecies Purification of Testicular Germ Cells1

    PubMed Central

    Lima, Ana C.; Jung, Min; Rusch, Jannette; Usmani, Abul; Lopes, Alexandra M.; Conrad, Donald F.

    2016-01-01

    Advanced methods of cellular purification are required to apply genome technology to the study of spermatogenesis. One approach, based on flow cytometry of murine testicular cells stained with Hoechst-33342 (Ho-FACS), has been extensively optimized and currently allows the isolation of nine germ cell types. This staining technique is straightforward to implement, is highly effective at purifying specific germ cell types, and yields sufficient cell numbers for high-throughput studies. Ho-FACS is a technique that does not require species-specific markers, but whose applicability to other species is largely unexplored. We hypothesized that, because of the similar cell physiology of spermatogenesis across mammals, Ho-FACS could be used to produce highly purified subpopulations of germ cells in mammals other than mouse. To test this hypothesis, we applied Ho-FACS to four mammalian species that are widely used in testis research: Rattus norvegicus, Cavia porcellus, Canis familiaris, and Sus scrofa domesticus. We successfully isolated four germ cell populations from these species with average purity of 79% for spermatocytes, 90% for spermatids, and 66% for spermatogonia. Additionally, we compare the performance of mechanical and chemical dissociation for each species, and propose an optimized gating strategy to better discriminate round and elongating spermatids in the mouse, which can potentially be applied to other species. Our work indicates that spermatogenesis may be uniquely accessible among mammalian developmental systems, as a single set of reagents may be sufficient to isolate germ cell populations from many different mammalian species, opening new avenues in the fields of development and male reproductive biology. PMID:27557646

  9. Development of a pheasant interspecies primordial germ cell transfer to chicken embryo: effect of donor cell sex on chimeric semen production.

    PubMed

    Kang, S J; Choi, J W; Park, K J; Lee, Y M; Kim, T M; Sohn, S H; Lim, J M; Han, J Y

    2009-09-01

    This study was conducted to evaluate whether the sex of donor primordial germ cells (PGCs) influences production of chimeric semen from recipient hatchlings produced by interspecies transfer between pheasant (Phasianus colchicus) and chicken (Gallus gallus). Pheasant PGCs were retrieved from 7-d-old embryos and subsequently transferred into circulatory blood of 2.5-d-old (Stage 17) embryos. The sex of embryos was discerned 3 to 6 days after laying, and in preliminary study, overall rate of embryo survival after sexing was 74.6% with male-to-female ratio of 0.49 to 0.51. In Experiment 1, magnetic-activated cell sorting (MACS) using QCR1 antibody was effective for enriching the population of male and female PGCs in gonadal cells (9.2- to 12.5-fold and 10.8- to 19.5-fold increase, respectively). In Experiment 2, an increase in the number of hatchlings producing chimeric semen was detected after the homosexual transfer of male-to-male compared with that after the heterosexual transfer of female-to-male (68% to 88%). Significant increase was found in the frequency of chimeric semen production (0.96 to 1.68 times); production of pheasant progenies by artificial insemination using chimeric semen was also increased in the homosexual transfer (0 to 3 cases). In conclusion, the homosexual PGC transfer of male-to-male yielded better rate of generating pheasant progenies after test cross-reproduction than that of the heterosexual transfer of female-to-male, which could improve the efficiency of interspecies germ cell transfer system.

  10. Histopathology of pineal germ cell tumors.

    PubMed

    Vasiljevic, A; Szathmari, A; Champier, J; Fèvre-Montange, M; Jouvet, A

    2015-01-01

    Germ cell tumors (GCTs) classically occur in gonads. However, they are the most frequent neoplasms in the pineal region. The pineal location of GCTs may be caused by the neoplastic transformation of a primordial germ cell that has mismigrated. The World Health Organization (WHO) recognizes 5 histological types of intracranial GCTs: germinoma and non-germinomatous tumors including embryonal carcinoma, yolk sac tumor, choriocarcinoma and mature or immature teratoma. Germinomas and teratomas are frequently encountered as pure tumors whereas the other types are mostly part of mixed GCTs. In this situation, the neuropathologist has to be able to identify each component of a GCT. When diagnosis is difficult, use of recent immunohistochemical markers such as OCT(octamer-binding transcription factor)3/4, Glypican 3, SALL(sal-like protein)4 may be required. OCT3/4 is helpful in the diagnosis of germinomas, Glypican 3 in the diagnosis of yolk sac tumors and SALL4 in the diagnosis of the germ cell nature of an intracranial tumor. When the germ cell nature of a pineal tumor is doubtful, the finding of an isochromosome 12p suggests the diagnosis of GCT. The final pathological report should always be confronted with the clinical data, especially the serum or cerebrospinal fluid levels of β-human chorionic gonadotropin (HCG) and alpha-fetoprotein.

  11. Regulation of germ line stem cell homeostasis

    PubMed Central

    Garcia, T.X.; Hofmann, M.C.

    2015-01-01

    Mammalian spermatogenesis is a complex process in which spermatogonial stem cells of the testis (SSCs) develop to ultimately form spermatozoa. In the seminiferous epithelium, SSCs self-renew to maintain the pool of stem cells throughout life, or they differentiate to generate a large number of germ cells. A balance between SSC self-renewal and differentiation is therefore essential to maintain normal spermatogenesis and fertility. Stem cell homeostasis is tightly regulated by signals from the surrounding microenvironment, or SSC niche. By physically supporting the SSCs and providing them with these extrinsic molecules, the Sertoli cell is the main component of the niche. Earlier studies have demonstrated that GDNF and CYP26B1, produced by Sertoli cells, are crucial for self-renewal of the SSC pool and maintenance of the undifferentiated state. Down-regulating the production of these molecules is therefore equally important to allow germ cell differentiation. We propose that NOTCH signaling in Sertoli cells is a crucial regulator of germ cell fate by counteracting these stimulatory factors to maintain stem cell homeostasis. Dysregulation of this essential niche component can lead by itself to sterility or facilitate testicular cancer development.

  12. Production of functional gametes from cryopreserved primordial germ cells of the Japanese quail.

    PubMed

    Nakamura, Yoshiaki; Tasai, Mariko; Takeda, Kumiko; Nirasawa, Keijiro; Tagami, Takahiro

    2013-12-17

    The Japanese quail (Coturnix japonica) is a valuable bird as both an experimental animal, for a wide range of scientific disciplines, and an agricultural animal, for the production of eggs and meat. Cryopreservation of PGCs would be a feasible strategy for the conservation of both male and female fertility cells in Japanese quail. However, the effects of freeze-thaw treatment on viability, migration ability and germline transmission ability of quail PGCs still remain unclear. In the present study, male and female PGCs were isolated from the blood of 2-day-old embryos, which were cooled by slow freezing and then cryopreserved at -196 C for 77-185 days, respectively. The average recovery rate of PGCs after freeze-thawing was 47.0%. The viability of PGCs in the frozen group was significantly lower than that of the control group (P<0.05) (85.5% vs. 95.1%). Both fresh and Frozen-thawed PGCs that were intravascularly transplanted into recipient embryos migrated toward and were incorporated into recipient gonads, although the number of PGCs settled in the gonads was 48.5% lower in the frozen group than in the unfrozen control group (P<0.05). Genetic cross analysis revealed that one female and two male recipients produced live progeny derived from the frozen-thawed PGCs. The frequency of donor-derived offspring was slightly lower than that of unfrozen controls, but the difference was not significant (4.0 vs. 14.0%). These results revealed that freeze-thaw treatment causes a decrease in viability, migration ability and germline transmission ability of PGCs in quail.

  13. Embryonic stem cells: testing the germ-cell theory.

    PubMed

    Hochedlinger, Konrad

    2011-10-25

    The exact cellular origin of embryonic stem cells remains elusive. Now a new study provides compelling evidence that embryonic stem cells, established under conventional culture conditions, originate from a transient germ-cell state.

  14. Standard-Dose Combination Chemotherapy or High-Dose Combination Chemotherapy and Stem Cell Transplant in Treating Patients With Relapsed or Refractory Germ Cell Tumors

    ClinicalTrials.gov

    2017-08-15

    Germ Cell Tumor; Teratoma; Choriocarcinoma; Germinoma; Mixed Germ Cell Tumor; Yolk Sac Tumor; Childhood Teratoma; Malignant Germ Cell Neoplasm; Extragonadal Seminoma; Non-seminomatous Germ Cell Tumor; Seminoma

  15. Refuting the hypothesis that the acquisition of germ plasm accelerates animal evolution

    PubMed Central

    Whittle, Carrie A.; Extavour, Cassandra G.

    2016-01-01

    Primordial germ cells (PGCs) give rise to the germ line in animals. PGCs are specified during embryogenesis either by an ancestral mechanism of cell–cell signalling (induction) or by a derived mechanism of maternally provided germ plasm (preformation). Recently, a hypothesis was set forth purporting that germ plasm liberates selective constraint and accelerates an organism's protein sequence evolution, especially for genes from early developmental stages, thereby leading to animal species radiations; empirical validation has been claimed in vertebrates. Here we present findings from global rates of protein evolution in vertebrates and invertebrates refuting this hypothesis. Contrary to assertions of the hypothesis, we find no effect of preformation on protein sequence evolution, the evolutionary rates of early-stage developmental genes, or on species diversification. We conclude that the hypothesis is mechanistically implausible, and our multi-faceted analysis shows no empirical support for any of its predictions. PMID:27577604

  16. Inducible Sterilization of Zebrafish by Disruption of Primordial Germ Cell Migration

    PubMed Central

    Wong, Ten-Tsao; Collodi, Paul

    2013-01-01

    During zebrafish development, a gradient of stromal-derived factor 1a (Sdf1a) provides the directional cue that guides the migration of the primordial germ cells (PGCs) to the gonadal tissue. Here we describe a method to produce large numbers of infertile fish by inducing ubiquitous expression of Sdf1a in zebrafish embryos resulting in disruption of the normal PGC migration pattern. A transgenic line of zebrafish, Tg(hsp70:sdf1a-nanos3, EGFP), was generated that expresses Sdf1a under the control of the heat-shock protein 70 (hsp70) promoter and nanos3 3?UTR. To better visualize the PGCs, the Tg(hsp70:sdf1a-nanos3, EGFP) fish were crossed with another transgenic line, Tg(kop:DsRed-nanos3), that expresses DsRed driven by the PGC-specific kop promoter. Heat treatment of the transgenic embryos caused an induction of Sdf1a expression throughout the embryo resulting in the disruption of their normal migration. Optimal embryo survival and disruption of PGC migration was achieved when transgenic embryos at the 4- to 8-cell stage were incubated at 34.5°C for 18 hours. Under these conditions, disruption of PGC migration was observed in 100% of the embryos. Sixty-four adult fish were developed from three separate batches of heat-treated embryos and all were found to be infertile males. When each male was paired with a wild-type female, only unfertilized eggs were produced and histological examination revealed that each of the adult male fish possessed severely under-developed gonads that lacked gametes. The results demonstrate that inducible Sdf1a expression is an efficient and reliable strategy to produce infertile fish. This approach makes it convenient to generate large numbers of infertile adult fish while also providing the capability to maintain a fertile brood stock. PMID:23826390

  17. Human second trimester amniotic fluid cells are able to create embryoid body-like structures in vitro and to show typical expression profiles of embryonic and primordial germ cells.

    PubMed

    Antonucci, Ivana; Di Pietro, Roberta; Alfonsi, Melissa; Centurione, Maria Antonietta; Centurione, Lucia; Sancilio, Silvia; Pelagatti, Francesca; D'Amico, Maria Angela; Di Baldassarre, Angela; Piattelli, Adriano; Tetè, Stefano; Palka, Giandomenico; Borlongan, Cesar V; Stuppia, Liborio

    2014-01-01

    Human amniotic fluid-derived stem cells (AFSCs) represent a novel class of broadly multipotent stem cells sharing characteristics of both embryonic and adult stem cells. However, both the origin of these cells and their actual properties in terms of pluripotent differentiation potential are still debated. In order to verify the presence of features of pluripotency in human second trimester AFSCs, we have investigated the ability of these cells to form in vitro three-dimensional aggregates, known as embryoid bodies (EBs), and to express specific genes of embryonic stem cells (ESCs) and primordial germ cells (PGCs). EBs were obtained after 5 days of AFSC culture in suspension and showed positivity for alkaline phosphatase (AP) staining and for specific markers of pluripotency (OCT4 and SOX2). Moreover, EB-derived cells showed the expression of specific transcripts of the three germ layers. RT-PCR analysis, carried out at different culture times (second, third, fourth, fifth, and eighth passages), revealed the presence of specific markers of ESCs (such as FGF4 and DAPPA4), as well as of markers typical of PGCs and, in particular, genes involved in early stages of germ cell development (Fragilis, Stella, Vasa, c-Kit, Rnf17). Finally, the expression of genes related to the control of DNA methylation (DNMT3A, DNMT3b1, DNMT1, DNMT3L, MBD1, MBD2, MBD3, MDB4, MeCP2), as well as the lack of inactivation of the X-chromosome in female samples, was also demonstrated. Taken together, these data provide further evidence for the presence of common features among human AFSCs, PGCs, and ESCs.

  18. Dnd knockout ablates germ cells and demonstrates germ cell independent sex differentiation in Atlantic salmon

    PubMed Central

    Wargelius, Anna; Leininger, Sven; Skaftnesmo, Kai Ove; Kleppe, Lene; Andersson, Eva; Taranger, Geir Lasse; Schulz, Rüdiger W; Edvardsen, Rolf B

    2016-01-01

    Introgression of farmed salmon escapees into wild stocks is a major threat to the genetic integrity of wild populations. Using germ cell-free fish in aquaculture may mitigate this problem. Our study investigated whether it is possible to produce germ cell-free salmon in F0 by using CRISPR-Cas9 to knock out dnd, a factor required for germ cell survival in vertebrates. To avoid studying mosaic animals, sgRNA targeting alb was simultaneously used as a visual tracer since the phenotype of alb KO is complete loss of pigmentation. Induced mutations for the tracer (alb) and the target (dnd) genes were highly correlated and produced germ cell-less fish lacking pigmentation, underlining the suitability of alb KO to serve as tracer for targeted double allelic mutations in F0 animals in species with prohibitively long generation times. This is also the first report describing dnd knockout in any fish species. Analyzing gene expression and histology of dnd KO fish revealed that sex differentiation of the somatic compartment does not depend on the presence of germ cells. However, the organization of the ovarian somatic compartment seems compromised in mutant fish. PMID:26888627

  19. Dnd knockout ablates germ cells and demonstrates germ cell independent sex differentiation in Atlantic salmon.

    PubMed

    Wargelius, Anna; Leininger, Sven; Skaftnesmo, Kai Ove; Kleppe, Lene; Andersson, Eva; Taranger, Geir Lasse; Schulz, Rüdiger W; Edvardsen, Rolf B

    2016-02-18

    Introgression of farmed salmon escapees into wild stocks is a major threat to the genetic integrity of wild populations. Using germ cell-free fish in aquaculture may mitigate this problem. Our study investigated whether it is possible to produce germ cell-free salmon in F0 by using CRISPR-Cas9 to knock out dnd, a factor required for germ cell survival in vertebrates. To avoid studying mosaic animals, sgRNA targeting alb was simultaneously used as a visual tracer since the phenotype of alb KO is complete loss of pigmentation. Induced mutations for the tracer (alb) and the target (dnd) genes were highly correlated and produced germ cell-less fish lacking pigmentation, underlining the suitability of alb KO to serve as tracer for targeted double allelic mutations in F0 animals in species with prohibitively long generation times. This is also the first report describing dnd knockout in any fish species. Analyzing gene expression and histology of dnd KO fish revealed that sex differentiation of the somatic compartment does not depend on the presence of germ cells. However, the organization of the ovarian somatic compartment seems compromised in mutant fish.

  20. Human primordial germ cell formation is diminished by exposure to environmental toxicants acting through the AHR signaling pathway.

    PubMed

    Kee, Kehkooi; Flores, Martha; Cedars, Marcelle I; Reijo Pera, Renee A

    2010-09-01

    Historically, effects of environmental toxicants on human development have been deduced via epidemiological studies because direct experimental analysis has not been possible. However, in recent years, the derivation of human pluripotent stem cells has provided a potential experimental system to directly probe human development. Here, we used human embryonic stem cells (hESCs) to study the effect of environmental toxicants on human germ cell development, with a focus on differentiation of the founding population of primordial germ cells (PGCs), which will go on to form the oocytes of the adult. We demonstrate that human PGC numbers are specifically reduced by exposure to polycyclic aromatic hydrocarbons (PAHs), a group of toxicants common in air pollutants released from gasoline combustion or tobacco smoke. Further, we demonstrate that the adverse effects of PAH exposure are mediated through the aromatic hydrocarbon receptor (AHR) and BAX pathway. This study demonstrates the utility of hESCs as a model system for direct examination of the molecular and genetic pathways of environmental toxicants on human germ cell development.

  1. Cancer testis antigen expression in testicular germ cell tumorigenesis.

    PubMed

    Bode, Peter K; Thielken, Andrea; Brandt, Simone; Barghorn, André; Lohe, Bernd; Knuth, Alexander; Moch, Holger

    2014-06-01

    Cancer testis antigens are encoded by germ line-associated genes that are present in normal germ cells of testis and ovary but not in differentiated tissues. Their expression in various human cancer types has been interpreted as 're-expression' or as intratumoral progenitor cell signature. Cancer testis antigen expression patterns have not yet been studied in germ cell tumorigenesis with specific emphasis on intratubular germ cell neoplasia unclassified as a precursor lesion for testicular germ cell tumors. Immunohistochemistry was used to study MAGEA3, MAGEA4, MAGEC1, GAGE1 and CTAG1B expression in 325 primary testicular germ cell tumors, including 94 mixed germ cell tumors. Seminomatous and non-seminomatous components were separately arranged and evaluated on tissue microarrays. Spermatogonia in the normal testis were positive, whereas intratubular germ cell neoplasia unclassified was negative for all five CT antigens. Cancer testis antigen expression was only found in 3% (CTAG1B), 10% (GAGE1, MAGEA4), 33% (MAGEA3) and 40% (MAGEC1) of classic seminoma but not in non-seminomatous testicular germ cell tumors. In contrast, all spermatocytic seminomas were positive for cancer testis antigens. These data are consistent with a different cell origin in spermatocytic seminoma compared with classic seminoma and support a progression model with loss of cancer testis antigens in early tumorigenesis of testicular germ cell tumors and later re-expression in a subset of seminomas.

  2. Molecular biology of testicular germ cell tumors.

    PubMed

    Gonzalez-Exposito, R; Merino, M; Aguayo, C

    2016-06-01

    Testicular germ cell tumors (TGCTs) are the most common solid tumors in young adult men. They constitute a unique pathology because of their embryonic and germ origin and their special behavior. Genetic predisposition, environmental factors involved in their development and genetic aberrations have been under study in many works throughout the last years trying to explain the susceptibility and the transformation mechanism of TGCTs. Despite the high rate of cure in this type of tumors because its particular sensitivity to cisplatin, there are tumors resistant to chemotherapy for which it is needed to find new therapies. In the present work, it has been carried out a literature review on the most important molecular aspects involved in the onset and development of such tumors, as well as a review of the major developments regarding prognostic factors, new prognostic biomarkers and the possibility of new targeted therapies.

  3. Sex Specification and Heterogeneity of Primordial Germ Cells in Mice.

    PubMed

    Sakashita, Akihiko; Kawabata, Yukiko; Jincho, Yuko; Tajima, Shiun; Kumamoto, Soichiro; Kobayashi, Hisato; Matsui, Yasuhisa; Kono, Tomohiro

    2015-01-01

    In mice, primordial germ cells migrate into the genital ridges by embryonic day 13.5 (E13.5), where they are then subjected to a sex-specific fate with female and male primordial germ cells undergoing mitotic arrest and meiosis, respectively. However, the sex-specific basis of primordial germ cell differentiation is poorly understood. The aim of this study was to investigate the sex-specific features of mouse primordial germ cells. We performed RNA-sequencing (seq) of E13.5 female and male mouse primordial germ cells using next-generation sequencing. We identified 651 and 428 differentially expressed transcripts (>2-fold, P < 0.05) in female and male primordial germ cells, respectively. Of these, many transcription factors were identified. Gene ontology and network analysis revealed differing functions of the identified female- and male-specific genes that were associated with primordial germ cell acquisition of sex-specific properties required for differentiation into germ cells. Furthermore, DNA methylation and ChIP-seq analysis of histone modifications showed that hypomethylated gene promoter regions were bound with H3K4me3 and H3K27me3. Our global transcriptome data showed that in mice, primordial germ cells are decisively assigned to a sex-specific differentiation program by E13.5, which is necessary for the development of vital germ cells.

  4. On the development of extragonadal and gonadal human germ cells.

    PubMed

    Heeren, A Marijne; He, Nannan; de Souza, Aline F; Goercharn-Ramlal, Angelique; van Iperen, Liesbeth; Roost, Matthias S; Gomes Fernandes, Maria M; van der Westerlaken, Lucette A J; Chuva de Sousa Lopes, Susana M

    2016-02-01

    Human germ cells originate in an extragonadal location and have to migrate to colonize the gonadal primordia at around seven weeks of gestation (W7, or five weeks post conception). Many germ cells are lost along the way and should enter apoptosis, but some escape and can give rise to extragonadal germ cell tumors. Due to the common somatic origin of gonads and adrenal cortex, we investigated whether ectopic germ cells were present in the human adrenals. Germ cells expressing DDX4 and/or POU5F1 were present in male and female human adrenals in the first and second trimester. However, in contrast to what has been described in mice, where 'adrenal' and 'ovarian' germ cells seem to enter meiosis in synchrony, we were unable to observe meiotic entry in human 'adrenal' germ cells until W22. By contrast, 'ovarian' germ cells at W22 showed a pronounced asynchronous meiotic entry. Interestingly, we observed that immature POU5F1+ germ cells in both first and second trimester ovaries still expressed the neural crest marker TUBB3, reminiscent of their migratory phase. Our findings highlight species-specific differences in early gametogenesis between mice and humans. We report the presence of a population of ectopic germ cells in the human adrenals during development. © 2016. Published by The Company of Biologists Ltd.

  5. On the development of extragonadal and gonadal human germ cells

    PubMed Central

    Heeren, A. Marijne; He, Nannan; de Souza, Aline F.; Goercharn-Ramlal, Angelique; van Iperen, Liesbeth; Roost, Matthias S.; Gomes Fernandes, Maria M.; van der Westerlaken, Lucette A. J.; Chuva de Sousa Lopes, Susana M.

    2016-01-01

    ABSTRACT Human germ cells originate in an extragonadal location and have to migrate to colonize the gonadal primordia at around seven weeks of gestation (W7, or five weeks post conception). Many germ cells are lost along the way and should enter apoptosis, but some escape and can give rise to extragonadal germ cell tumors. Due to the common somatic origin of gonads and adrenal cortex, we investigated whether ectopic germ cells were present in the human adrenals. Germ cells expressing DDX4 and/or POU5F1 were present in male and female human adrenals in the first and second trimester. However, in contrast to what has been described in mice, where ‘adrenal’ and ‘ovarian’ germ cells seem to enter meiosis in synchrony, we were unable to observe meiotic entry in human ‘adrenal’ germ cells until W22. By contrast, ‘ovarian’ germ cells at W22 showed a pronounced asynchronous meiotic entry. Interestingly, we observed that immature POU5F1+ germ cells in both first and second trimester ovaries still expressed the neural crest marker TUBB3, reminiscent of their migratory phase. Our findings highlight species-specific differences in early gametogenesis between mice and humans. We report the presence of a population of ectopic germ cells in the human adrenals during development. PMID:26834021

  6. Spindle assembly checkpoint gene mdf-1 regulates germ cell proliferation in response to nutrition signals in C. elegans.

    PubMed

    Watanabe, Sonoko; Yamamoto, Takaharu G; Kitagawa, Risa

    2008-04-09

    When newly hatched Caenorhabditis elegans larvae are starved, their primordial germ cells (PGCs) arrest in the post-S phase. This starvation-induced PGC arrest is mediated by the DAF-18/PTEN-AKT-1/PKB nutrient-sensing pathway. Here, we report that the conserved spindle assembly checkpoint (SAC) component MDF-1/MAD1 is required for the PGC arrest. We identified 2 Akt kinase phosphorylation sites on MDF-1. Expression of a non-phosphorylatable mutant MDF-1 partially suppressed the defect in the starvation-induced PGC arrest in L1 larvae lacking DAF-18, suggesting that MDF-1 regulates germ cell proliferation as a downstream target of AKT-1, thereby demonstrating a functional link between cell-cycle regulation by the SAC components and nutrient sensing by DAF-18-AKT-1 during post-embryonic development. The phosphorylation status of MDF-1 affects its binding to another SAC component, MDF-2/MAD2. The loss of MDF-2 or another SAC component also caused inappropriate germ cell proliferation, but the defect was less severe than that caused by mdf-1 hemizygosity, suggesting that MDF-1 causes the PGC arrest by two mechanisms, one involving MDF-2 and another that is independent of other SAC components.

  7. Spindle assembly checkpoint gene mdf-1 regulates germ cell proliferation in response to nutrition signals in C. elegans

    PubMed Central

    Watanabe, Sonoko; Yamamoto, Takaharu G; Kitagawa, Risa

    2008-01-01

    When newly hatched Caenorhabditis elegans larvae are starved, their primordial germ cells (PGCs) arrest in the post-S phase. This starvation-induced PGC arrest is mediated by the DAF-18/PTEN–AKT-1/PKB nutrient-sensing pathway. Here, we report that the conserved spindle assembly checkpoint (SAC) component MDF-1/MAD1 is required for the PGC arrest. We identified 2 Akt kinase phosphorylation sites on MDF-1. Expression of a non-phosphorylatable mutant MDF-1 partially suppressed the defect in the starvation-induced PGC arrest in L1 larvae lacking DAF-18, suggesting that MDF-1 regulates germ cell proliferation as a downstream target of AKT-1, thereby demonstrating a functional link between cell-cycle regulation by the SAC components and nutrient sensing by DAF-18–AKT-1 during post-embryonic development. The phosphorylation status of MDF-1 affects its binding to another SAC component, MDF-2/MAD2. The loss of MDF-2 or another SAC component also caused inappropriate germ cell proliferation, but the defect was less severe than that caused by mdf-1 hemizygosity, suggesting that MDF-1 causes the PGC arrest by two mechanisms, one involving MDF-2 and another that is independent of other SAC components. PMID:18309291

  8. Combination Chemotherapy in Treating Young Patients With Recurrent or Resistant Malignant Germ Cell Tumors

    ClinicalTrials.gov

    2017-02-07

    Childhood Extracranial Germ Cell Tumor; Childhood Extragonadal Germ Cell Tumor; Childhood Malignant Ovarian Germ Cell Tumor; Childhood Malignant Testicular Germ Cell Tumor; Ovarian Choriocarcinoma; Ovarian Embryonal Carcinoma; Ovarian Yolk Sac Tumor; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Malignant Testicular Germ Cell Tumor; Recurrent Ovarian Germ Cell Tumor; Testicular Choriocarcinoma; Testicular Choriocarcinoma and Embryonal Carcinoma; Testicular Choriocarcinoma and Yolk Sac Tumor; Testicular Embryonal Carcinoma; Testicular Embryonal Carcinoma and Yolk Sac Tumor; Testicular Yolk Sac Tumor

  9. Regulation of germ cell meiosis in the fetal ovary.

    PubMed

    Spiller, Cassy M; Bowles, Josephine; Koopman, Peter

    2012-01-01

    Fertility depends on correct regulation of meiosis, the special form of cell division that gives rise to haploid gametes. In female mammals, germ cells enter meiosis during fetal ovarian development, while germ cells in males avoid entering meiosis until puberty. Decades of research have shown that meiotic entry, and germ cell sex determination, are not initiated intrinsically within the germ cells. Instead, meiosis is induced by signals produced by the surrounding somatic cells. More recently, retinoic acid (RA), the active derivative of vitamin A, has been implicated in meiotic induction during fetal XX and postnatal XY germ cell development. Evidence for an intricate system of RA synthesis and degradation in the fetal ovary and testis has emerged, explaining past observations of infertility in vitamin A-deficient rodents. Here we review how meiosis is triggered in fetal ovarian germ cells, paying special attention to the role of RA in this process.

  10. Mitotic Arrest in Teratoma Susceptible Fetal Male Germ Cells

    PubMed Central

    Western, Patrick S.; Ralli, Rachael A.; Wakeling, Stephanie I.; Lo, Camden; van den Bergen, Jocelyn A.; Miles, Denise C.; Sinclair, Andrew H.

    2011-01-01

    Formation of germ cell derived teratomas occurs in mice of the 129/SvJ strain, but not in C57Bl/6 inbred or CD1 outbred mice. Despite this, there have been few comparative studies aimed at determining the similarities and differences between teratoma susceptible and non-susceptible mouse strains. This study examines the entry of fetal germ cells into the male pathway and mitotic arrest in 129T2/SvJ mice. We find that although the entry of fetal germ cells into mitotic arrest is similar between 129T2/SvJ, C57Bl/6 and CD1 mice, there were significant differences in the size and germ cell content of the testis cords in these strains. In 129T2/SvJ mice germ cell mitotic arrest involves upregulation of p27KIP1, p15INK4B, activation of RB, the expression of male germ cell differentiation markers NANOS2, DNMT3L and MILI and repression of the pluripotency network. The germ-line markers DPPA2 and DPPA4 show reciprocal repression and upregulation, respectively, while FGFR3 is substantially enriched in the nucleus of differentiating male germ cells. Further understanding of fetal male germ cell differentiation promises to provide insight into disorders of the testis and germ cell lineage, such as testis tumour formation and infertility. PMID:21674058

  11. Finding their way: themes in germ cell migration

    PubMed Central

    Barton, Lacy J.; LeBlanc, Michelle G.; Lehmann, Ruth

    2016-01-01

    Embryonic germ cell migration is a vital component of the germline lifecycle. The translocation of germ cells from the place of origin to the developing somatic gonad involves several processes including passive movements with underlying tissues, transepithelial migration, cell adhesion dynamics, the establishment of environmental guidance cues and the ability to sustain directed migration. How germ cells accomplish these feats in established model organisms will be discussed in this review, with a focus on recent discoveries and themes conserved across species. PMID:27484857

  12. Setdb1 is required for germline development and silencing of H3K9me3-marked endogenous retroviruses in primordial germ cells

    PubMed Central

    Liu, Sheng; Brind’Amour, Julie; Karimi, Mohammad M.; Shirane, Kenjiro; Bogutz, Aaron; Lefebvre, Louis; Sasaki, Hiroyuki; Shinkai, Yoichi

    2014-01-01

    Transcription of endogenous retroviruses (ERVs) is inhibited by de novo DNA methylation during gametogenesis, a process initiated after birth in oocytes and at approximately embryonic day 15.5 (E15.5) in prospermatogonia. Earlier in germline development, the genome, including most retrotransposons, is progressively demethylated. Young ERVK and ERV1 elements, however, retain intermediate methylation levels. As DNA methylation reaches a low point in E13.5 primordial germ cells (PGCs) of both sexes, we determined whether retrotransposons are marked by H3K9me3 and H3K27me3 using a recently developed low-input ChIP-seq (chromatin immunoprecipitation [ChIP] combined with deep sequencing) method. Although these repressive histone modifications are found predominantly on distinct genomic regions in E13.5 PGCs, they concurrently mark partially methylated long terminal repeats (LTRs) and LINE1 elements. Germline-specific conditional knockout of the H3K9 methyltransferase SETDB1 yields a decrease of both marks and DNA methylation at H3K9me3-enriched retrotransposon families. Strikingly, Setdb1 knockout E13.5 PGCs show concomitant derepression of many marked ERVs, including intracisternal A particle (IAP), ETn, and ERVK10C elements, and ERV-proximal genes, a subset in a sex-dependent manner. Furthermore, Setdb1 deficiency is associated with a reduced number of male E13.5 PGCs and postnatal hypogonadism in both sexes. Taken together, these observations reveal that SETDB1 is an essential guardian against proviral expression prior to the onset of de novo DNA methylation in the germline. PMID:25228647

  13. Molecular mechanisms of male germ cell differentiation.

    PubMed

    Hecht, N B

    1998-07-01

    During spermatogenesis, diploid stem cells differentiate, undergo meiosis, and transform into haploid spermatozoa. As this precisely timed series of events proceeds, chromosomal ploidy is reduced and the nucleosomes of the chromatin are replaced by a transcriptionally quiescent protamine-containing nucleus. The premature termination of transcription during the haploid phase of spermatogenesis necessitates an especially prominent role for posttranscriptional regulation in the temporal and spatial expression of many testis-specific proteins and isozymes. In this review article, discussion will focus on novel mechanisms regulating gene expression in mammalian male germ cells from genome to protein.

  14. Primordial Germ Cell-Mediated Chimera Technology Produces Viable Pure-Line Houbara Bustard Offspring: Potential for Repopulating an Endangered Species

    PubMed Central

    Wernery, Ulrich; Liu, Chunhai; Baskar, Vijay; Guerineche, Zhor; Khazanehdari, Kamal A.; Saleem, Shazia; Kinne, Jörg; Wernery, Renate

    2010-01-01

    Background The Houbara bustard (Chlamydotis undulata) is a wild seasonal breeding bird populating arid sandy semi-desert habitats in North Africa and the Middle East. Its population has declined drastically during the last two decades and it is classified as vulnerable. Captive breeding programmes have, hitherto, been unsuccessful in reviving population numbers and thus radical technological solutions are essential for the long term survival of this species. The purpose of this study was to investigate the use of primordial germ cell-mediated chimera technology to produce viable Houbara bustard offspring. Methodology/Principal Findings Embryonic gonadal tissue was dissected from Houbara bustard embryos at eight days post-incubation. Subsequently, Houbara tissue containing gonadal primordial germ cells (gPGCs) was injected into White Leghorn chicken (Gallus gallus domesticus) embryos, producing 83/138 surviving male chimeric embryos, of which 35 chimeric roosters reached sexual maturity after 5 months. The incorporation and differentiation of Houbara gPGCs in chimeric chicken testis were assessed by PCR with Houbara-specific primers and 31.3% (5/16) gonads collected from the injected chicken embryos showed the presence of donor Houbara cells. A total of 302 semen samples from 34 chimeric roosters were analyzed and eight were confirmed as germline chimeras. Semen samples from these eight roosters were used to artificially inseminate three female Houbara bustards. Subsequently, 45 Houbara eggs were obtained and incubated, two of which were fertile. One egg hatched as a male live born Houbara; the other was female but died before hatching. Genotyping confirmed that the male chick was a pure-line Houbara derived from a chimeric rooster. Conclusion This study demonstrates for the first time that Houbara gPGCs can migrate, differentiate and eventually give rise to functional sperm in the chimeric chicken testis. This approach may provide a promising tool for propagation

  15. Lin28a regulates germ cell pool size and fertility

    PubMed Central

    Shinoda, Gen; de Soysa, T. Yvanka; Seligson, Marc T.; Yabuuchi, Akiko; Fujiwara, Yuko; Huang, Pei Yi; Hagan, John P.; Gregory, Richard I.; Moss, Eric G.; Daley, George Q.

    2013-01-01

    Overexpression of LIN28A is associated with human germ cell tumors and promotes primordial germ cell (PGC) development from embryonic stem cells in vitro and in chimeric mice. Knockdown of Lin28a inhibits PGC development in vitro, but how constitutional Lin28a deficiency affects the mammalian reproductive system in vivo remains unknown. Here, we generated Lin28a knockout (KO) mice and found that Lin28a deficiency compromises the size of the germ cell pool in both males and females by affecting PGC proliferation during embryogenesis. Interestingly however, in Lin28a KO males the germ cell pool partially recovers during postnatal expansion, while fertility remains impaired in both males and females mated to wild type mice. Embryonic overexpression of let-7, a microRNA negatively regulated by Lin28a, reduces the germ cell pool, corroborating the role of the Lin28a/let-7 axis in regulating the germ lineage. PMID:23378032

  16. Differentiation of germ cells and gametes from stem cells.

    PubMed

    Marques-Mari, A I; Lacham-Kaplan, O; Medrano, J V; Pellicer, A; Simón, C

    2009-01-01

    Advances in stem cell research have opened new perspectives for regenerative and reproductive medicine. Stem cells (SC) can differentiate under appropriate in vitro and in vivo conditions into different cell types. Several groups have reported their ability to differentiate SCs into germline cells, and some of them have been successful in obtaining male and female gamete-like cells by using different methodologies. This review summarizes the current knowledge in this field and emphasizes significant embryological, genetic and epigenetic aspects of germ cells and gametes in vitro differentiation in humans and other species, highlighting major obstacles that need to be overcome for successful gametogenesis in culture: studies reporting development of germ cell-like cells from murine and human embryonic (ESC) and somatic SCs are critically reviewed. Published studies indicate that germ cells can be consistently differentiated from mouse and human ESC. However, further differentiation of germ cells through gametogenesis still has important genetic and epigenetic obstacles to be efficient. Differentiation of germ cells from SCs has the potential of becoming a future source of gametes for research use, although further investigation is needed to understand and develop the appropriate niches and culture conditions. Additionally, if genetic and epigenetic methodological limitations could be solved, therapeutic opportunities could be also considered.

  17. Black carp vasa identifies embryonic and gonadal germ cells.

    PubMed

    Xue, Ting; Yu, Miao; Pan, Qihua; Wang, Yizhou; Fang, Jian; Li, Lingyu; Deng, Yu; Chen, Kai; Wang, Qian; Chen, Tiansheng

    2017-07-01

    Identification of molecular markers is an essential step in the study of germ cells. Vasa is an RNA helicase and a well-known germ cell marker that plays a crucial role in germ cell development. Here, we identified the Vasa homolog termed Mpvasa as the first germ cell marker in black carp (Mylopharyngodon piceus). First, a 2819-bp full-length Mpvasa complementary DNA (cDNA) was cloned by PCR using degenerated primers of conserved sequences and gene-specific primers. The Mpvasa cDNA sequence encodes a 637-amino acid protein that contains eight conserved characteristic motifs of the DEAD box protein family, and shares high identity to grass carp (81%) and zebrafish (74%) vasa homologs. Second, Mpvasa expression was restricted to the gonad in adulthood by RT-PCR and Western blot analysis. The dynamic patterns of temporal-spatial expression of Mpvasa during gametogenesis were examined by in situ hybridization, and Mpvasa transcripts were strictly detected in gonadal germ cells throughout oogenesis, predominantly in immature oocytes (stage I, II, and III oocytes). Third, Mpvasa transcripts were highly detected in unfertilized eggs and early embryos, and the signal indicated a dynamic migration of the primordial germ cells during embryogenesis, suggesting that Mpvasa transcripts were maternally inherited and specifically distributed in germ cells. Taken together, these results demonstrated that Mpvasa is an applicable molecular marker for identification of gonadal and embryonic germ cells, which facilitates the isolation and utilization of germ cells in black carp.

  18. Primordial Germ Cells: Current Knowledge and Perspectives

    PubMed Central

    Nikolic, Aleksandar; Volarevic, Vladislav; Armstrong, Lyle; Lako, Majlinda; Stojkovic, Miodrag

    2016-01-01

    Infertility is a condition that occurs very frequently and understanding what defines normal fertility is crucial to helping patients. Causes of infertility are numerous and the treatment often does not lead to desired pregnancy especially when there is a lack of functional gametes. In humans, the primordial germ cell (PGC) is the primary undifferentiated stem cell type that will differentiate towards gametes: spermatozoa or oocytes. With the development of stem cell biology and differentiation protocols, PGC can be obtained from pluripotent stem cells providing a new therapeutic possibility to treat infertile couples. Recent studies demonstrated that viable mouse pups could be obtained from in vitro differentiated stem cells suggesting that translation of these results to human is closer. Therefore, the aim of this review is to summarize current knowledge about PGC indicating the perspective of their use in both research and medical application for the treatment of infertility. PMID:26635880

  19. Why do primordial germ cells migrate through an embryo and what does it mean for biological evolution?

    PubMed

    Olovnikov, A M

    2013-10-01

    An explanation of the role of primordial germ cell (PGC) migration during embryogenesis is proposed. According to the hypothesis, various PGCs during their migrations through an early embryo are contacting with anlagen of organs and acquiring nonidentical organ specificities. An individual PGC gets such an organ specificity, which corresponds to specificity of the first anlage with which this PGC has the first contact. As a result, the cellular descendants of PGCs (oocytes or spermatocytes) will express nonidentical organ-specific receptors, hence becoming functionally heterogeneous. Therefore, each clone of germ cells becomes capable of recognizing specifically the molecular signals that correspond only to "its" organ of the body. Such signals are produced by the body's organ when it functions in an extreme mode. Signals from the "exercising" organ of the body are delivered to the gonad only via the brain retransmitter, which is composed of neurons grouped as virtual organs of a homunculus. Homunculi are so-called somatotopic maps of the skeletomotor and other parts of the body represented in the brain. Signals, as complexes of regulatory RNAs and proteins, are transported from the "exercising" organ of the body to the corresponding virtual organ of the homunculus where they are processed and then forwarded to the gonad. The organ-specific signal will be selectively recognized by certain gametocytes according to their organ specificity, and then it will initiate the directed epimutation in the gametocyte genome. The nonrandomness of the gene order in chromosomes, that is the synteny and genetic map, is controlled by the so-called creatron that consolidates the soma and germline into a united system, providing the possibility of evolutionary responses of an organism to environmental influences.

  20. Intracranial germ cell tumor mimicking anorexia nervosa.

    PubMed

    Andreu Martínez, F J; Martínez Mateu, J M

    2006-12-01

    We report on a case of a 23 year-old female diagnosed as having a germ-cell tumour located in the sellar region. The patient referred anorexia, psychic disorders, weight loss of 15 kilograms and secondary amenorrhea during the previous three years. This is the reason why the patient was diagnosed as having anorexia nervosa. Subsequently, the patient presented some endocrine dysfunction. MRI revealed the existence of a lesion located in suprasellar and hypothalamic regions. This case shows that the presence of intracranial tumours next to the hypothalamus must be borne in mind as a rare but real possibility in cases of anorexia nervosa, specially in those non-typical cases.

  1. Germ cell migration across Sertoli cell tight junctions.

    PubMed

    Smith, Benjamin E; Braun, Robert E

    2012-11-09

    The blood-testis barrier includes strands of tight junctions between somatic Sertoli cells that restricts solutes from crossing the paracellular space, creating a microenvironment within seminiferous tubules and providing immune privilege to meiotic and postmeiotic cells. Large cysts of germ cells transit the Sertoli cell tight junctions (SCTJs) without compromising their integrity. We used confocal microscopy to visualize SCTJ components during germ cell cyst migration across the SCTJs. Cysts become enclosed within a network of transient compartments fully bounded by old and new tight junctions. Dissolution of the old tight junctions releases the germ cells into the adluminal compartment, thus completing transit across the blood-testis barrier. Claudin 3, a tight junction protein, is transiently incorporated into new tight junctions and then replaced by claudin 11.

  2. Induction of Germ Cell-like Cells from Porcine Induced Pluripotent Stem Cells

    PubMed Central

    Wang, Hanning; Xiang, Jinzhu; Zhang, Wei; Li, Junhong; Wei, Qingqing; Zhong, Liang; Ouyang, Hongsheng; Han, Jianyong

    2016-01-01

    The ability to generate germ cells from pluripotent stem cells (PSCs) is valuable for human regenerative medicine and animal breeding. Germ cell-like cells (GCLCs) have been differentiated from mouse and human PSCs, but not from porcine PSCs, which are considered an ideal model for stem cell applications. Here, we developed a defined culture system for the induction of primordial germ cell-like cells (PGCLCs) from porcine induced PSCs (piPSCs). The identity of the PGCLCs was characterized by observing cell morphology, detecting germ cell marker gene expression and evaluating epigenetic properties. PGCLCs could further differentiate into spermatogonial stem cell-like cells (SSCLCs) in vitro. Importantly, meiosis occurred during SSCLC induction. Xenotransplantation of GCLCs into seminiferous tubules of infertile immunodeficient mice resulted in immunohistochemically identifiable germ cells in vivo. Overall, our study provides a feasible strategy for directing piPSCs to the germ cell fate and lays a foundation for exploring germ cell development mechanisms. PMID:27264660

  3. Isolation and transplantation of sturgeon early-stage germ cells.

    PubMed

    Pšenička, Martin; Saito, Taiju; Linhartová, Zuzana; Gazo, Ievgeniia

    2015-04-01

    We report, for the first time, a series of baseline techniques comprising isolation and transplantation of female and male early-stage germ cells in sturgeon to generate a germline chimera as a potential tool for surrogate reproduction and gene banking. Cells were dissociated from testis, characterized by mostly spermatogonia, and from ovary, exclusively comprising oogonia and previtellogenic oocytes, of Acipenser baerii, using 0.3% trypsin (2 hours, 23 °C) dissolved in PBS, isotonic with blood plasma. The dissociated germ cells were sorted by Percoll gradient centrifugation followed by immunolabeling with germ cell-specific vasa antibody DDX4, while 10% to 30% Percoll solution contained 79.4% and 70.8% labeled testicular and ovarian cells. Sorted germ cells were transplanted into a cavity close to a presumptive genital ridge of newly hatched heterospecific Acipenser ruthenus larvae with fluorescein isothiocyanate-labeled endogenous primordial germ cells. The transplanted germ cells were randomly distributed in the body cavity through 30-day posttransplantation (dpt). Subsequently, the cells were organized into genital ridges 50 dpt and proliferated 90 dpt. The number of both transplanted and endogenous germ cells significantly increased from 18.1, 22.2, and 29.1 (30 dpt) to 108.5, 90.8, and 118.5 (90 dpt) in ovarian, testicular, and endogenous germ cells, respectively (P < 0.05). The efficiency of transplantation was 60% (counted 90 dpt). Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Environmentally Induced Transgenerational Epigenetic Reprogramming of Primordial Germ Cells and the Subsequent Germ Line

    PubMed Central

    Skinner, Michael K.; Haque, Carlos Guerrero-Bosagna M.; Nilsson, Eric; Bhandari, Ramji; McCarrey, John R.

    2013-01-01

    A number of environmental factors (e.g. toxicants) have been shown to promote the epigenetic transgenerational inheritance of disease and phenotypic variation. Transgenerational inheritance requires the germline transmission of altered epigenetic information between generations in the absence of direct environmental exposures. The primary periods for epigenetic programming of the germ line are those associated with primordial germ cell development and subsequent fetal germline development. The current study examined the actions of an agricultural fungicide vinclozolin on gestating female (F0 generation) progeny in regards to the primordial germ cell (PGC) epigenetic reprogramming of the F3 generation (i.e. great-grandchildren). The F3 generation germline transcriptome and epigenome (DNA methylation) were altered transgenerationally. Interestingly, disruptions in DNA methylation patterns and altered transcriptomes were distinct between germ cells at the onset of gonadal sex determination at embryonic day 13 (E13) and after cord formation in the testis at embryonic day 16 (E16). A larger number of DNA methylation abnormalities (epimutations) and transcriptional alterations were observed in the E13 germ cells than in the E16 germ cells. These observations indicate that altered transgenerational epigenetic reprogramming and function of the male germline is a component of vinclozolin induced epigenetic transgenerational inheritance of disease. Insights into the molecular control of germline transmitted epigenetic inheritance are provided. PMID:23869203

  5. Environmentally induced transgenerational epigenetic reprogramming of primordial germ cells and the subsequent germ line.

    PubMed

    Skinner, Michael K; Guerrero-Bosagna, Carlos; Haque, M; Nilsson, Eric; Bhandari, Ramji; McCarrey, John R

    2013-01-01

    A number of environmental factors (e.g. toxicants) have been shown to promote the epigenetic transgenerational inheritance of disease and phenotypic variation. Transgenerational inheritance requires the germline transmission of altered epigenetic information between generations in the absence of direct environmental exposures. The primary periods for epigenetic programming of the germ line are those associated with primordial germ cell development and subsequent fetal germline development. The current study examined the actions of an agricultural fungicide vinclozolin on gestating female (F0 generation) progeny in regards to the primordial germ cell (PGC) epigenetic reprogramming of the F3 generation (i.e. great-grandchildren). The F3 generation germline transcriptome and epigenome (DNA methylation) were altered transgenerationally. Interestingly, disruptions in DNA methylation patterns and altered transcriptomes were distinct between germ cells at the onset of gonadal sex determination at embryonic day 13 (E13) and after cord formation in the testis at embryonic day 16 (E16). A larger number of DNA methylation abnormalities (epimutations) and transcriptional alterations were observed in the E13 germ cells than in the E16 germ cells. These observations indicate that altered transgenerational epigenetic reprogramming and function of the male germline is a component of vinclozolin induced epigenetic transgenerational inheritance of disease. Insights into the molecular control of germline transmitted epigenetic inheritance are provided.

  6. Translational Control of Germ Cell Decisions.

    PubMed

    Pushpa, Kumari; Kumar, Ganga Anil; Subramaniam, Kuppuswamy

    2017-01-01

    Germline poses unique challenges to gene expression control at the transcriptional level. While the embryonic germline maintains a global hold on new mRNA transcription, the female adult germline produces transcripts that are not translated into proteins until embryogenesis of subsequent generation. As a consequence, translational control plays a central role in governing various germ cell decisions including the formation of primordial germ cells, self-renewal/differentiation decisions in the adult germline, onset of gametogenesis and oocyte maturation. Mechanistically, several common themes such as asymmetric localization of mRNAs, conserved RNA-binding proteins that control translation by 3' UTR binding, translational activation by the cytoplasmic elongation of the polyA tail and the assembly of mRNA-protein complexes called mRNPs have emerged from the studies on Caenorhabditis elegans, Xenopus and Drosophila. How mRNPs assemble, what influences their dynamics, and how a particular 3' UTR-binding protein turns on the translation of certain mRNAs while turning off other mRNAs at the same time and space are key challenges for future work.

  7. Expression of the apoptosis inducer gene head involution defective in primordial germ cells of the Drosophila embryo requires eiger, p53, and loki function.

    PubMed

    Maezawa, Takanobu; Arita, Kayo; Shigenobu, Shuji; Kobayashi, Satoru

    2009-05-01

    Nanos (Nos) is an evolutionarily conserved protein essential for the maintenance of primordial germ cells (PGCs). In Drosophila, the PGCs or pole cells express head involution defective (hid), which is required for caspase activation, but its translation is repressed by maternal Nos. In the absence of Nos activity, translation of hid mRNA into protein induces apoptosis in pole cells. However, it remains unclear how hid mRNA is regulated in pole cells. Here, we report that hid expression requires eiger (egr), a tumor necrosis factor ligand (TNF) homologue, which is induced in pole cells by decapentaplegic (dpp). In addition, we demonstrate that p53 and loki (lok), a damage-activated kinase known to be required for p53 phosphorylation, are both required for hid expression in pole cells. Since maternal lok mRNA is enriched in pole cells, it is possible that ubiquitously distributed p53 is activated in pole cells by maternal Lok. We propose that hid expression is activated in a pole cell-specific manner by loki/p53 and dpp/egr during embryogenesis.

  8. The Biology of the Germ line in Echinoderms

    PubMed Central

    Wessel, Gary M.; Brayboy, Lynae; Fresques, Tara; Gustafson, Eric A.; Oulhen, Nathalie; Ramos, Isabela; Reich, Adrian; Swartz, S. Zachary; Yajima, Mamiko; Zazueta, Vanessa

    2014-01-01

    SUMMARY The formation of the germ line in an embryo marks a fresh round of reproductive potential. The developmental stage and location within the embryo where the primordial germ cells (PGCs) form, however, differs markedly among species. In many animals, the germ line is formed by an inherited mechanism, in which molecules made and selectively partitioned within the oocyte drive the early development of cells that acquire this material to a germ-line fate. In contrast, the germ line of other animals is fated by an inductive mechanism that involves signaling between cells that directs this specialized fate. In this review, we explore the mechanisms of germ-line determination in echinoderms, an early-branching sister group to the chordates. One member of the phylum, sea urchins, appears to use an inherited mechanism of germ-line formation, whereas their relatives, the sea stars, appear to use an inductive mechanism. We first integrate the experimental results currently available for germ line determination in the sea urchin, for which considerable new information is available, and then broaden the investigation to the lesser-known mechanisms in sea stars and other echinoderms. Even with this limited insight, it appears that sea stars, and perhaps the majority of the echinoderm taxon, rely on inductive mechanisms for germ-line fate determination. This enables a strongly contrasted picture for germ-line determination in this phylum, but one for which transitions between different modes of germ-line determination might now be experimentally addressed. PMID:23900765

  9. The biology of the germ line in echinoderms.

    PubMed

    Wessel, Gary M; Brayboy, Lynae; Fresques, Tara; Gustafson, Eric A; Oulhen, Nathalie; Ramos, Isabela; Reich, Adrian; Swartz, S Zachary; Yajima, Mamiko; Zazueta, Vanessa

    2014-08-01

    The formation of the germ line in an embryo marks a fresh round of reproductive potential. The developmental stage and location within the embryo where the primordial germ cells (PGCs) form, however, differs markedly among species. In many animals, the germ line is formed by an inherited mechanism, in which molecules made and selectively partitioned within the oocyte drive the early development of cells that acquire this material to a germ-line fate. In contrast, the germ line of other animals is fated by an inductive mechanism that involves signaling between cells that directs this specialized fate. In this review, we explore the mechanisms of germ-line determination in echinoderms, an early-branching sister group to the chordates. One member of the phylum, sea urchins, appears to use an inherited mechanism of germ-line formation, whereas their relatives, the sea stars, appear to use an inductive mechanism. We first integrate the experimental results currently available for germ-line determination in the sea urchin, for which considerable new information is available, and then broaden the investigation to the lesser-known mechanisms in sea stars and other echinoderms. Even with this limited insight, it appears that sea stars, and perhaps the majority of the echinoderm taxon, rely on inductive mechanisms for germ-line fate determination. This enables a strongly contrasted picture for germ-line determination in this phylum, but one for which transitions between different modes of germ-line determination might now be experimentally addressed.

  10. The Formation of Germ Cell for Organizational Learning

    ERIC Educational Resources Information Center

    Ivaldi, Silvia; Scaratti, Giuseppe

    2016-01-01

    Purpose: The aim of the paper is to analyze the process of "germ cell" formation by framing it as an opportunity for promoting organizational learning and transformation. The paper aims to specifically answer two research questions: Why does the "germ cell" have a pivotal role in organization's transformation? and Which…

  11. Poland syndrome with intracranial germ cell tumor in a child.

    PubMed

    Elli, Murat; Oğur, Gönül; Dağdemir, Ayhan; Pinarli, Güçlü; Ceyhan, Meltem; Dağçinar, Adnan

    2009-01-01

    Poland syndrome is an uncommon unilateral deformity of chest wall and upper extremity with variable manifestations. Although numerous case reports of Poland syndrome associated with malignancies have been published, intracranial germ cell tumor in Poland syndrome has not been previously reported. The authors describe a 15-year-old male patient with intracranial germ cell tumor and Poland syndrome.

  12. Is Tobacco Smoke a Germ-Cell Mutagen?

    EPA Science Inventory

    Although no international organization exists to declare whether an agent is a germ-cell mutagen, tobacco smoke may be a human germ-cell mutagen. In the mouse, tobacco smoke induces a significant increase in the mutation frequency at an expanded simple tandem repeat (ESTR) locus....

  13. The Formation of Germ Cell for Organizational Learning

    ERIC Educational Resources Information Center

    Ivaldi, Silvia; Scaratti, Giuseppe

    2016-01-01

    Purpose: The aim of the paper is to analyze the process of "germ cell" formation by framing it as an opportunity for promoting organizational learning and transformation. The paper aims to specifically answer two research questions: Why does the "germ cell" have a pivotal role in organization's transformation? and Which…

  14. Is Tobacco Smoke a Germ-Cell Mutagen?

    EPA Science Inventory

    Although no international organization exists to declare whether an agent is a germ-cell mutagen, tobacco smoke may be a human germ-cell mutagen. In the mouse, tobacco smoke induces a significant increase in the mutation frequency at an expanded simple tandem repeat (ESTR) locus....

  15. Germ tube-specific antigens of Candida albicans cell walls

    SciTech Connect

    Sundstrom, P.R.

    1986-01-01

    Studies were performed to characterize the surface differences between blastospores and germ tubes of the pathogenic, dimorphic yeast, Candida albicans, and to identify components of yeast cells responsible for these differences. Investigation of surfaces differences of the two growth forms was facilitated by the production of rabbit antiserum prepared against Formalin-treated yeast possessing germ tubes. To prepare antiserum specific for germ tubes, this serum was adsorbed with stationary phase blastospores. Whereas the unadsorbed antiserum reacted with both blastospore and germ tube forms by immunofluorescence and Enzyme-Linked Immunosorbent Assay, the adsorbed antiserum did not react with blastospores but detected germ tube-specific antigens in hyphal forms. The differences between blastospores and germ tubes of Candida albicans, were further studied by comparing enzymatic digests of cell walls of both growth forms in radiolabeled organisms. Organisms were labeled either on the surface with /sup 125/I, or metabolically with (/sup 35/S) methionine or (/sup 3/H) mannose. Three-surface-located components (as shown by antibody adsorption and elution experiments) were precipitated from Zymolase digests. All three components were mannoproteins as shown by their ability to bind Concanavalin A, and to be labeled in protein labeling procedures, and two of these (200,000 and 155,000 molecular weight) were germ tube specific, as shown by their ability to be precipitated by germ tube-specific antiserum. Monoclonal antibodies were prepared to C. albicans, using blastospores bearing germ tubes as immunogen.

  16. Hedgehog does not guide migrating Drosophila germ cells

    PubMed Central

    Renault, Andrew D.; Ricardo, Sara; Kunwar, Prabhat S.; Santos, Ana; Starz-Gaiano, Michelle; Stein, Jennifer; Lehmann, Ruth

    2009-01-01

    In many species, the germ cells, precursors of sperm and egg, migrate during embryogenesis. The signals that regulate this migration are thus essential for fertility. In flies, lipid signals have been shown to affect germ cell guidance. In particular, the synthesis of geranylgeranyl pyrophosphate through the 3-hydroxy-3-methyl-glutaryl coenzyme A reductase (Hmgcr) pathway is critical for attracting germ cells to their target tissue. In a genetic analysis of signaling pathways known to affect cell migration of other migratory cells, we failed to find a role for the Hedgehog (Hh) pathway in germ cell migration. However, previous reports had implicated Hh as a germ cell attractant in flies and suggested that Hh signaling is enhanced through the action of the Hmgcr pathway. We therefore repeated several critical experiments and carried out further experiments to test specifically whether Hh is a germ cell attractant in flies. In contrast to previously reported findings and consistent with findings in zebrafish our data do not support the notion that Hh has a direct role in the guidance of migrating germ cells in flies. PMID:19389345

  17. Meiosis and retrotransposon silencing during germ cell development in mice.

    PubMed

    Ollinger, Rupert; Reichmann, Judith; Adams, Ian R

    2010-03-01

    In mammals, germ cells derive from the pluripotent cells that are present early in embryogenesis, and then differentiate into male sperm or female eggs as development proceeds. Fusion between an egg and a sperm at fertilization allows genetic information from both parents to be transmitted to the next generation, and produces a pluripotent zygote to initiate the next round of embryogenesis. Meiosis is a central event in this self-perpetuating cycle that creates genetic diversity by generating new combinations of existing genetic alleles, and halves the number of chromosomes in the developing male and female germ cells to allow chromosome number to be maintained through successive generations. The developing germ cells also help to maintain genetic and chromosomal stability through the generations by protecting the genome from excessive de novo mutation. Several mouse mutants have recently been characterised whose germ cells exhibit defects in silencing the potentially mutagenic endogenous retroviruses and other retrotransposons that are prevalent in mammalian genomes, and these germ cells also exhibit defects in progression through meiosis. Here we review how mouse germ cells develop and proceed through meiosis, how mouse germ cells silence endogenous retroviruses and other retrotransposons, and discuss why silencing of endogenous retroviruses and other retrotransposons may be required for meiotic progression in mice.

  18. Alvocidib and Oxaliplatin With or Without Fluorouracil and Leucovorin Calcium in Treating Patients With Relapsed or Refractory Germ Cell Tumors

    ClinicalTrials.gov

    2017-01-20

    Recurrent Extragonadal Seminoma; Recurrent Malignant Extragonadal Germ Cell Tumor; Recurrent Malignant Extragonadal Non-Seminomatous Germ Cell Tumor; Recurrent Malignant Testicular Germ Cell Tumor; Recurrent Ovarian Germ Cell Tumor; Stage III Testicular Cancer; Stage IV Extragonadal Non-Seminomatous Germ Cell Tumor; Stage IV Extragonadal Seminoma; Stage IV Ovarian Germ Cell Tumor

  19. Global Landscape and Regulatory Principles of DNA Methylation Reprogramming for Germ Cell Specification by Mouse Pluripotent Stem Cells.

    PubMed

    Shirane, Kenjiro; Kurimoto, Kazuki; Yabuta, Yukihiro; Yamaji, Masashi; Satoh, Junko; Ito, Shinji; Watanabe, Akira; Hayashi, Katsuhiko; Saitou, Mitinori; Sasaki, Hiroyuki

    2016-10-10

    Specification of primordial germ cells (PGCs) activates epigenetic reprogramming for totipotency, the elucidation of which remains a fundamental challenge. Here, we uncover regulatory principles for DNA methylation reprogramming during in vitro PGC specification, in which mouse embryonic stem cells (ESCs) are induced into epiblast-like cells (EpiLCs) and then PGC-like cells (PGCLCs). While ESCs reorganize their methylome to form EpiLCs, PGCLCs essentially dilute the EpiLC methylome at constant, yet different, rates between unique sequence regions and repeats. ESCs form hypomethylated domains around pluripotency regulators for their activation, whereas PGCLCs create demethylation-sensitive domains around developmental regulators by accumulating abundant H3K27me3 for their repression. Loss of PRDM14 globally upregulates methylation and diminishes the hypomethylated domains, but it preserves demethylation-sensitive domains. Notably, female ESCs form hypomethylated lamina-associated domains, while female PGCLCs effectively reverse such states into a more normal configuration. Our findings illuminate the unique orchestration of DNA methylation and histone modification reprogramming during PGC specification. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Efficient genetic modification and germ-line transmission of primordial germ cells using piggyBac and Tol2 transposons.

    PubMed

    Macdonald, Joni; Taylor, Lorna; Sherman, Adrian; Kawakami, Koichi; Takahashi, Yoshiko; Sang, Helen M; McGrew, Michael J

    2012-06-05

    The derivation of germ-line competent avian primordial germ cells establishes a cell-based model system for the investigation of germ cell differentiation and the production of genetically modified animals. Current methods to modify primordial germ cells using DNA or retroviral vectors are inefficient and prone to epigenetic silencing. Here, we validate the use of transposable elements for the genetic manipulation of primordial germ cells. We demonstrate that chicken primordial germ cells can be modified in vitro using transposable elements. Both piggyBac and Tol2 transposons efficiently transpose primordial germ cells. Tol2 transposon integration sites were spread throughout both the macro- and microchromosomes of the chicken genome and were more prevalent in gene transcriptional units and intronic regions, consistent with transposon integrations observed in other species. We determined that the presence of insulator elements was not required for reporter gene expression from the integrated transposon. We further demonstrate that a gene-trap cassette carried in the Tol2 transposon can trap and mutate endogenous transcripts in primordial germ cells. Finally, we observed that modified primordial germ cells form functional gametes as demonstrated by the generation of transgenic offspring that correctly expressed a reporter gene carried in the transposon. Transposable elements are therefore efficient vectors for the genetic manipulation of primordial germ cells and the chicken genome.

  1. Testicular germ cell tumors: pathogenesis, diagnosis and treatment.

    PubMed

    Winter, Christian; Albers, Peter

    2011-01-01

    Testicular germ cell tumors represent the most common solid malignancy of young men aged 15-40 years. Histopathologically, testicular germ cell tumors are divided into two major groups: pure seminoma and nonseminoma. The pathogenesis of testicular germ cell tumors remains unknown; however, cryptorchidism is the main risk factor, and molecular studies have shown strong evidence of an association between genetic alterations and testicular germ cell tumors. In cases of suspicion for testicular germ cell tumor, a surgical exploration with orchiectomy is obligatory. After completion of diagnostic procedures, levels of serum tumor markers and the clinical stage based on the International Union Against Cancer tumor-node-metastasis classification should be defined. Patients with early-stage testicular germ cell tumors are treated by individualized risk stratification within a multidisciplinary approach. The individual management (surveillance, chemotherapy or radiotherapy) has to be balanced according to clinical features and the risk of short-term and long-term toxic effects. Treatment for metastatic tumors is based on risk stratification according to International Germ Cell Cancer Collaborative Group classification and is performed with cisplatin-based chemotherapy and residual tumor resection in cases of residual tumor lesion. High-dose chemotherapy represents a curative option for patients with second or subsequent relapses.

  2. Use of Stirred Suspension Bioreactors for Male Germ Cell Enrichment

    PubMed Central

    Sakib, Sadman; Dores, Camila; Rancourt, Derrick

    2016-01-01

    Spermatogenesis is a stem cell based system. Both therapeutic and biomedical research applications of spermatogonial stem cells require a large number of cells. However, there are only few germ line stem cells in the testis, contained in the fraction of undifferentiated spermatogonia. The lack of specific markers makes it difficult to isolate these cells. The long term maintenance and proliferation of nonrodent germ cells in culture has so far been met with limited success, partially due to the lack of highly enriched starting populations. Differential plating, which depends on the differential adhesion properties of testicular somatic and germ cells to tissue culture dishes, has been the method of choice for germ cell enrichment, especially for nonrodent germ cells. However, for large animals, this process becomes labor intensive and increases variability due to the need for extensive handling. Here, we describe the use of stirred suspension bioreactors, as a novel system for enriching undifferentiated germ cells from 1-week-old pigs. This method capitalizes on the adherent properties of somatic cells within a controlled environment, thus promoting the enrichment of progenitor cells with minimal handling and variability. PMID:27066790

  3. Evidence against a germ plasm in the milkweed bug Oncopeltus fasciatus, a hemimetabolous insect

    PubMed Central

    Ewen-Campen, Ben; Jones, Tamsin E. M.; Extavour, Cassandra G.

    2013-01-01

    Summary Primordial germ cell (PGC) formation in holometabolous insects like Drosophila melanogaster relies on maternally synthesised germ cell determinants that are asymmetrically localised to the oocyte posterior cortex. Embryonic nuclei that inherit this “germ plasm” acquire PGC fate. In contrast, historical studies of basally branching insects (Hemimetabola) suggest that a maternal requirement for germ line genes in PGC specification may be a derived character confined principally to Holometabola. However, there have been remarkably few investigations of germ line gene expression and function in hemimetabolous insects. Here we characterise PGC formation in the milkweed bug Oncopeltus fasciatus, a member of the sister group to Holometabola, thus providing an important evolutionary comparison to members of this clade. We examine the transcript distribution of orthologues of 19 Drosophila germ cell and/or germ plasm marker genes, and show that none of them localise asymmetrically within Oncopeltus oocytes or early embryos. Using multiple molecular and cytological criteria, we provide evidence that PGCs form after cellularisation at the site of gastrulation. Functional studies of vasa and tudor reveal that these genes are not required for germ cell formation, but that vasa is required in adult males for spermatogenesis. Taken together, our results provide evidence that Oncopeltus germ cells may form in the absence of germ plasm, consistent with the hypothesis that germ plasm is a derived strategy of germ cell specification in insects. PMID:23789106

  4. Evidence against a germ plasm in the milkweed bug Oncopeltus fasciatus, a hemimetabolous insect.

    PubMed

    Ewen-Campen, Ben; Jones, Tamsin E M; Extavour, Cassandra G

    2013-06-15

    Primordial germ cell (PGC) formation in holometabolous insects like Drosophila melanogaster relies on maternally synthesised germ cell determinants that are asymmetrically localised to the oocyte posterior cortex. Embryonic nuclei that inherit this "germ plasm" acquire PGC fate. In contrast, historical studies of basally branching insects (Hemimetabola) suggest that a maternal requirement for germ line genes in PGC specification may be a derived character confined principally to Holometabola. However, there have been remarkably few investigations of germ line gene expression and function in hemimetabolous insects. Here we characterise PGC formation in the milkweed bug Oncopeltus fasciatus, a member of the sister group to Holometabola, thus providing an important evolutionary comparison to members of this clade. We examine the transcript distribution of orthologues of 19 Drosophila germ cell and/or germ plasm marker genes, and show that none of them localise asymmetrically within Oncopeltus oocytes or early embryos. Using multiple molecular and cytological criteria, we provide evidence that PGCs form after cellularisation at the site of gastrulation. Functional studies of vasa and tudor reveal that these genes are not required for germ cell formation, but that vasa is required in adult males for spermatogenesis. Taken together, our results provide evidence that Oncopeltus germ cells may form in the absence of germ plasm, consistent with the hypothesis that germ plasm is a derived strategy of germ cell specification in insects.

  5. Epigenetic transitions in germ cell development and meiosis.

    PubMed

    Kota, Satya K; Feil, Robert

    2010-11-16

    Germ cell development is controlled by unique gene expression programs and involves epigenetic reprogramming of histone modifications and DNA methylation. The central event is meiosis, during which homologous chromosomes pair and recombine, processes that involve histone alterations. At unpaired regions, chromatin is repressed by meiotic silencing. After meiosis, male germ cells undergo chromatin remodeling, including histone-to-protamine replacement. Male and female germ cells are also differentially marked by parental imprints, which contribute to sex determination in insects and mediate genomic imprinting in mammals. Here, we review epigenetic transitions during gametogenesis and discuss novel insights from animal and human studies.

  6. Retinoic acid, meiosis and germ cell fate in mammals.

    PubMed

    Bowles, Josephine; Koopman, Peter

    2007-10-01

    Although mammalian sex is determined genetically, the sex-specific development of germ cells as sperm or oocytes is initiated by cues provided by the gonadal environment. During embryogenesis, germ cells in an ovary enter meiosis, thereby committing to oogenesis. By contrast, germ cells in a testicular environment do not enter meiosis until puberty. Recent findings indicate that the key to this sex-specific timing of meiosis entry is the presence or absence of the signaling molecule retinoic acid. Although this knowledge clarifies a long-standing mystery in reproductive biology, it also poses many new questions, which we discuss in this review.

  7. An Evolutionarily Conserved Plant RKD Factor Controls Germ Cell Differentiation.

    PubMed

    Koi, Satoshi; Hisanaga, Tetsuya; Sato, Katsutoshi; Shimamura, Masaki; Yamato, Katsuyuki T; Ishizaki, Kimitsune; Kohchi, Takayuki; Nakajima, Keiji

    2016-07-11

    In contrast to animals, in which the germ cell lineage is established during embryogenesis, plant germ cells are generated in reproductive organs via reprogramming of somatic cells. The factors that control germ cell differentiation and reprogramming in plants are poorly understood. Members of the RKD subfamily of plant-specific RWP-RK transcription factors have been implicated in egg cell formation in Arabidopsis based on their expression patterns and ability to cause an egg-like transcriptome upon ectopic expression [1]; however, genetic evidence of their involvement is lacking, due to possible genetic redundancy, haploid lethality, and the technical difficulty of analyzing egg cell differentiation in angiosperms. Here we analyzed the factors that govern germ cell formation in the liverwort Marchantia polymorpha. This recently revived model bryophyte has several characteristics that make it ideal for studies of germ cell formation, such as low levels of genetic redundancy, readily accessible germ cells, and the ability to propagate asexually via gemma formation [2, 3]. Our analyses revealed that MpRKD, a single RWP-RK factor closely related to angiosperm RKDs, is preferentially expressed in developing eggs and sperm precursors in M. polymorpha. Targeted disruption of MpRKD had no effect on the gross morphology of the vegetative and reproductive organs but led to striking defects in egg and sperm cell differentiation, demonstrating that MpRKD is an essential regulator of germ cell differentiation. Together with previous findings [1, 4-6], our results suggest that RKD factors are evolutionarily conserved regulators of germ cell differentiation in land plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Tritium effects on germ cells and fertility

    SciTech Connect

    Dobson, R.L.; Kwan, T.C.; Straume, T.

    1982-11-19

    Primordial oocytes in juvenile mice show acute gamma-ray LD/sub 50/ as low as 6 rad. This provides opportunities for determining dose-response relations at low doses and chronic exposure in the intact animal - conditions of particular interest for hazard evaluation. Examined in this way, /sup 3/HOH in body water is found to kill murine oocytes exponentially with dose, the LD/sub 50/ level for chronic exposure being only 2..mu..Ci/ml (delivering 0.4 rad/day). At very low doses and dose rates, where comparisons between tritium and other radiations are of special significance for radiological protection, the RBE of tritium compared with /sup 60/Co gamma radiation reaches approximately 3. Effects on murine fertility from tritium-induced oocyte loss have been quantified by reproductive capacity measurements. Chronic low-level exposure has been examined also in three primate species - squirrel, rhesus, and bonnet monkeys. In squirrel monkeys the ovarian germ-cell supply is 99% destroyed by the time of birth from prenatal exposure to body-water levels of /sup 3/HOH (administered in maternal drinking water) of only 3 ..mu..Ci/ml, the LD/sub 50/ level being 0.5 ..mu..Ci/ml (giving 0.1 rad/day), one fourth that in mice. Though not completely ruled out, similar high sensitivity of female germ cells has not been found in macaques; and it probably does not occur in man. The exquisite radiosensitivity of primordial oocytes in mice is apparently due to vulnerability of the plasma membrane (or something of similar geometry and location), not DNA. Evidence for this comes from tritium data as well as neutron studies. Tritium administered as /sup 3/HOH, and therefore generally distributed, is much more effective in killing murine oocytes than is tritium administered as /sup 3/H-TdR, localized in the nucleus. This situation in the mouse may have implications for estimating radiation genetic risk in the human female.

  9. Current Management of Refractory Germ Cell Tumors and Future Directions.

    PubMed

    Allen, J Clayton; Kirschner, Austin; Scarpato, Kristen R; Morgans, Alicia K

    2017-02-01

    We review current management strategies for patients with relapsed and refractory germ cell tumors (GCTs), defined as relapsed or persistent disease following at least one line of cisplatin-based chemotherapy. Additionally, we discuss future directions in the management of these patients. Recent studies involving targeted therapies have been disappointing. Nevertheless, studies of the management of refractory germ cell cancer are ongoing, with a focus on optimal utilization of high-dose chemotherapy and autologous stem cell transplant, as well as the role of immune checkpoint inhibitors in refractory germ cell tumors. Studies aiming to identify those patients who may benefit from more intensive treatment up front to prevent the development of refractory disease are also in progress. Testicular germ cell tumors are among the most curable of all solid tumor malignancies, with cure being possible even in the refractory, metastatic setting. Treatment of refractory disease remains a challenging clinical scenario, but potentially practice changing studies are ongoing.

  10. Epigenetics: a way to understand the origin and biology of testicular germ cell tumors.

    PubMed

    Okamoto, Keisei

    2012-06-01

    Testicular germ cell tumors are neoplasms carrying two unique features. First, testicular germ cell tumors have a pluripotential nature and show protean histology ranging from that of germ cells to embryonal and differentiated somatic cells. Therefore, testicular germ cell tumors are interesting resources positioned at a crossroad in developmental and neoplastic processes. The second unique feature of testicular germ cell tumors is their exquisite sensitivity to cisplatin-based chemotherapy. This review summarizes recent research progress in the epigenetics of testicular germ cell tumors in an attempt to explain the abovementioned biological and clinical characteristics of testicular germ cell tumors.

  11. Transgenic rodent assay for quantifying male germ cell mutant frequency.

    PubMed

    O'Brien, Jason M; Beal, Marc A; Gingerich, John D; Soper, Lynda; Douglas, George R; Yauk, Carole L; Marchetti, Francesco

    2014-08-06

    De novo mutations arise mostly in the male germline and may contribute to adverse health outcomes in subsequent generations. Traditional methods for assessing the induction of germ cell mutations require the use of large numbers of animals, making them impractical. As such, germ cell mutagenicity is rarely assessed during chemical testing and risk assessment. Herein, we describe an in vivo male germ cell mutation assay using a transgenic rodent model that is based on a recently approved Organisation for Economic Co-operation and Development (OECD) test guideline. This method uses an in vitro positive selection assay to measure in vivo mutations induced in a transgenic λgt10 vector bearing a reporter gene directly in the germ cells of exposed males. We further describe how the detection of mutations in the transgene recovered from germ cells can be used to characterize the stage-specific sensitivity of the various spermatogenic cell types to mutagen exposure by controlling three experimental parameters: the duration of exposure (administration time), the time between exposure and sample collection (sampling time), and the cell population collected for analysis. Because a large number of germ cells can be assayed from a single male, this method has superior sensitivity compared with traditional methods, requires fewer animals and therefore much less time and resources.

  12. Transgenic Rodent Assay for Quantifying Male Germ Cell Mutant Frequency

    PubMed Central

    O'Brien, Jason M.; Beal, Marc A.; Gingerich, John D.; Soper, Lynda; Douglas, George R.; Yauk, Carole L.; Marchetti, Francesco

    2014-01-01

    De novo mutations arise mostly in the male germline and may contribute to adverse health outcomes in subsequent generations. Traditional methods for assessing the induction of germ cell mutations require the use of large numbers of animals, making them impractical. As such, germ cell mutagenicity is rarely assessed during chemical testing and risk assessment. Herein, we describe an in vivo male germ cell mutation assay using a transgenic rodent model that is based on a recently approved Organisation for Economic Co-operation and Development (OECD) test guideline. This method uses an in vitro positive selection assay to measure in vivo mutations induced in a transgenic λgt10 vector bearing a reporter gene directly in the germ cells of exposed males. We further describe how the detection of mutations in the transgene recovered from germ cells can be used to characterize the stage-specific sensitivity of the various spermatogenic cell types to mutagen exposure by controlling three experimental parameters: the duration of exposure (administration time), the time between exposure and sample collection (sampling time), and the cell population collected for analysis. Because a large number of germ cells can be assayed from a single male, this method has superior sensitivity compared with traditional methods, requires fewer animals and therefore much less time and resources. PMID:25145276

  13. Female germ cell loss from radiation and chemical exposures

    SciTech Connect

    Dobson, R.L.; Felton, J.S.

    1983-01-01

    Female germ cells in some mammals are extremely sensitive to killing by ionizing radiation, especially during development. Primordial oocytes in juvenile mice have an LD50 of only 6-7 rad, and the germ cell pool in squirrel monkeys is destroyed by prenatal exposure of 0.7 rad/day. Sensitivity varies greatly with species and germ cell stage. Unusually high sensitivity has not been found in macaques and may not occur in man, but this has not been established for all developmental stages. The exquisite oocyte radiosensitivity in mice apparently reflects vulnerability of the plasma membrane, not DNA, which may have implications for estimating human genetic risks. Germ cells can be killed also by chemicals. Such oocyte loss, with similarities to radiation effects, is under increasing study, including chemotherapy observations in women. More than 75 compounds have been tested in mice, with in vivo toxicity quantified by oocyte loss; certain chemicals apparently act on the membrane.

  14. Lipid phosphate phosphatase activity regulates dispersal and bilateral sorting of embryonic germ cells in Drosophila

    PubMed Central

    Renault, Andrew D.; Kunwar, Prabhat S.; Lehmann, Ruth

    2010-01-01

    In Drosophila, germ cell survival and directionality of migration are controlled by two lipid phosphate phosphatases (LPP), wunen (wun) and wunen-2 (wun2). wun wun2 double mutant analysis reveals that the two genes, hereafter collectively called wunens, act redundantly in primordial germ cells. We find that wunens mediate germ cell-germ cell repulsion and that this repulsion is necessary for germ cell dispersal and proper transepithelial migration at the onset of migration and for the equal sorting of the germ cells between the two embryonic gonads during their migration. We propose that this dispersal function optimizes adult fecundity by assuring maximal germ cell occupancy of both gonads. Furthermore, we find that the requirement for wunens in germ cell survival can be eliminated by blocking germ cell migration. We suggest that this essential function of Wunen is needed to maintain cell integrity in actively migrating germ cells. PMID:20431117

  15. Baldness, acne and testicular germ cell tumors

    PubMed Central

    Trabert, Britton; Sigurdson, Alice J.; Sweeney, Anne M.; Amato, Robert J.; Strom, Sara S.; McGlynn, Katherine A.

    2013-01-01

    Androgen levels during critical periods of testicular development may be involved in the etiology of testicular germ cell tumors (TGCT). We evaluated the roles of adolescent and early adult life correlates of androgen exposure and TGCT in a hospital-based case control study. TGCT cases (n=187) and controls (n=148), matched on age, race and state of residence, participated in the study. Unconditional logistic regression was used to estimate associations between TGCT and male pattern baldness, severe acne, markers of puberty onset and body size. Cases were significantly less likely to report hair loss than controls (OR, 0.6; 95% CI, 0.4, 1.0). Amount of hair loss, increasing age at onset and increasing rate of loss were all inversely associated with TGCT (rate of hair loss: p-trend=0.03; age at onset: p-trend=0.03; amount of hair loss: p-trend=0.01). History of severe acne was inversely associated with TGCT (OR, 0.5; 95% CI, 0.3, 0.9) and height was positively associated with TGCT (p-trend=0.02). Increased endogenous androgen levels during puberty and early adulthood may be associated with decreased risk of TGCT. Additional studies of endogenous hormone levels during puberty and early adult life are warranted, especially studies evaluating the role of androgen synthesis, metabolism and uptake. PMID:21128977

  16. FGF control of E-cadherin targeting in the Drosophila midgut impacts on primordial germ cell motility.

    PubMed

    Parés, Guillem; Ricardo, Sara

    2016-01-15

    Embryo formation requires tight regulation and coordination of adhesion in multiple cell types. By undertaking imaging, three-dimensional (3D) reconstructions and genetic analysis during posterior midgut morphogenesis in Drosophila, we find a new requirement for the conserved fibroblast growth factor (FGF) signaling pathway in the maintenance of epithelial cell adhesion through FGF modulation of zygotic E-cadherin. During Drosophila gastrulation, primordial germ cells (PGCs) are transported with the posterior midgut while it undergoes dynamic cell shape changes. In embryos mutant for the FGF signaling pathway components Branchless and Breathless, zygotic E-cadherin is not targeted to adherens junctions, causing midgut pocket collapse, which impacts on PGC movement. We find that the ventral midline also requires FGF signaling to maintain cell-cell adhesion. We show that FGF signaling regulates the distribution of zygotic E-cadherin during early embryonic development to maintain cell-cell adhesion in the posterior midgut and the ventral midline, a role that is likely crucial in other tissues undergoing active cell shape changes with higher adhesive needs.

  17. Lin28a regulates germ cell pool size and fertility.

    PubMed

    Shinoda, Gen; De Soysa, T Yvanka; Seligson, Marc T; Yabuuchi, Akiko; Fujiwara, Yuko; Huang, Pei Yi; Hagan, John P; Gregory, Richard I; Moss, Eric G; Daley, George Q

    2013-05-01

    Overexpression of LIN28A is associated with human germ cell tumors and promotes primordial germ cell (PGC) development from embryonic stem cells in vitro and in chimeric mice. Knockdown of Lin28a inhibits PGC development in vitro, but how constitutional Lin28a deficiency affects the mammalian reproductive system in vivo remains unknown. Here, we generated Lin28a knockout (KO) mice and found that Lin28a deficiency compromises the size of the germ cell pool in both males and females by affecting PGC proliferation during embryogenesis. Interestingly however, in Lin28a KO males, the germ cell pool partially recovers during postnatal expansion, while fertility remains impaired in both males and females mated to wild-type mice. Embryonic overexpression of let-7, a microRNA negatively regulated by Lin28a, reduces the germ cell pool, corroborating the role of the Lin28a/let-7 axis in regulating the germ lineage. Copyright © 2013 AlphaMed Press.

  18. CYP1A1 based on metabolism of xenobiotics by cytochrome P450 regulates chicken male germ cell differentiation.

    PubMed

    Li, Dong; Wang, Man; Cheng, Shaoze; Zhang, Chen; Wang, Yilin; Zhang, Wenhui; Zhao, Ruifeng; Sun, Changhua; Zhang, Yani; Li, Bichun

    2017-04-01

    This study aimed to explore the regulatory mechanism of metabolism of xenobiotics by cytochrome P450 during the differentiation process of chicken embryonic stem cells (ESCs) into spermatogonial stem cells (SSCs) and consummate the induction differentiation system of chicken embryonic stem cells (cESCs) into SSCs in vitro. We performed RNA-Seq in highly purified male ESCs, male primordial germ cells (PGCs), and SSCs that are associated with the male germ cell differentiation. Thereinto, the metabolism of xenobiotics by cytochrome P450 was selected and analyzed with Venny among male ESC vs male PGC, male PGC vs SSC, and male ESC vs SSC groups and several candidates differentially expressed genes (DEGs) were excavated. Finally, quantitative real-time PCR (qRT-PCR) detected related DEGs under the condition of retinoic acid (RA) induction in vitro, and the expressions were compared with RNA-Seq. By knocking down CYP1A1, we detected the effect of CYP1A1-mediated metabolism of xenobiotics by cytochrome P450 on male germ cell differentiation by qRT-PCR and immunocytochemistry. Results showed that 17,742 DEGs were found during differentiation of ESCs into SSCs and enriched in 72 differently significant pathways. Thereinto, the metabolism of xenobiotics by cytochrome P450 was involved in the whole differentiation process of ESCs into SSCs and several candidate DEGs: CYP1A1, CYP3A4, CYP2D6, ALDH3B1, and ALDH1A3 were expressed with the same trend with RNA-Seq. Knockdown of CYP1A1 caused male germ cell differentiation under restrictions. Our findings showed that the metabolism of xenobiotics by cytochrome P450 was significantly different during the process of male germ cell differentiation and was persistently activated when we induced cESCs to differentiate into SSCs with RA in vitro, which illustrated that the metabolism of xenobiotics by cytochrome P450 played a crucial role in the differentiation process of ESCs into SSCs.

  19. The crucial role of Activin A on the formation of primordial germ cell-like cells from skin-derived stem cells in vitro.

    PubMed

    Sun, Rui; Sun, Yuan-Chao; Ge, Wei; Tan, Hui; Cheng, Shun-Feng; Yin, Shen; Sun, Xiao-Feng; Li, Lan; Dyce, Paul; Li, Julang; Yang, Xiao; Shi, Qing-Hua; Shen, Wei

    2015-01-01

    Primordial germ cells (PGCs) are founder cells of the germ cell lineage, and can be differentiated from stem cells in an induced system in vitro. However, the induction conditions need to be optimized in order to improve the differentiation efficiency. Activin A (ActA) is a member of the TGF-β super family and plays an important role in oogenesis and folliculogenesis. In the present study, we found that ActA promoted PGC-like cells (PGCLCs) formation from mouse skin-derived stem cells (SDSCs) in both embryoid body-like structure (EBLS) differentiation and the co-culture stage in a dose dependent manner. ActA treatment (100 ng/ml) during EBLS differentiation stage and further co-cultured for 6 days without ActA significantly increased PGCLCs from 53.2% to 82.8%, and as well as EBLS differentiation without ActA followed by co-cultured with 100 ng/ml ActA for 4 to 12 days with the percentage of PGCLCs increasing markedly in vitro. Moreover, mice treated with ActA at 100 ng/kg body weight from embryonic day (E) 5.5-12.5 led to more PGCs formation. However, the stimulating effects of ActA were interrupted by Smad3 RNAi, and in an in vitro cultured Smad3(-/-) mouse skin cells scenario. SMAD3 is thus likely a key effecter molecule in the ActA signaling pathway. In addition, we found that the expression of some epiblast cell markers, Fgf5, Dnmt3a, Dnmt3b and Wnt3, was increased in EBLSs cultured for 4 days or PGCLCs co-cultured for 12 days with ActA treatment. Interestingly, at 16 days of differentiation, the percentage of PGCLCs was decreased in the presence of ActA, but the expression of meiosis-relative genes, such as Stra8, Dmc1, Sycp3 and Sycp1, was increased. In conclusion, our data here demonstrated that ActA can promote PGCLC formation from SDSCs in vitro, at early stages of differentiation, and affect meiotic initiation of PGCLCs in later stages.

  20. Control of male germ-cell development in flowering plants.

    PubMed

    Singh, Mohan B; Bhalla, Prem L

    2007-11-01

    Plant reproduction is vital for species survival, and is also central to the production of food for human consumption. Seeds result from the successful fertilization of male and female gametes, but our understanding of the development, differentiation of gamete lineages and fertilization processes in higher plants is limited. Germ cells in animals diverge from somatic cells early in embryo development, whereas plants have distinct vegetative and reproductive phases in which gametes are formed from somatic cells after the plant has made the transition to flowering and the formation of the reproductive organs. Recently, novel insights into the molecular mechanisms underlying male germ-line initiation and male gamete development in plants have been obtained. Transcriptional repression of male germ-line genes in non-male germ-line cells have been identified as a key mechanism for spatial and temporal control of male germ-line development. This review focuses on molecular events controlling male germ-line development especially, on the nature and regulation of gene expression programs operating in male gametes of flowering plants.

  1. Hormonal control of germ cell development and spermatogenesis.

    PubMed

    O'Shaughnessy, Peter J

    2014-05-01

    Spermatogenesis is completely dependent on the pituitary hormone follicle-stimulating hormone (FSH) and androgens locally produced in response to luteinising hormone (LH). This dual control has been known since the 1930s and 1940s but more recent work, particularly using transgenic mice, has allowed us to determine which parts of the spermatogenic pathway are regulated by each hormone. During the first spermatogenic cycle after puberty both FSH and androgen act to limit the massive wave of germ cell apoptosis which occurs at this time. The established role of FSH in all cycles is to increase spermatogonial and subsequent spermatocyte numbers with a likely effect also on spermiation. Mice lacking FSH or its receptor are fertile, albeit with reduced germ cell numbers, and so this hormone is not an essential regulator of spermatogenesis but acts to optimise germ cell production Androgens also appear to regulate spermatogonial proliferation but, crucially, they are also required to allow spermatocytes to complete meiosis and form spermatids. Animals lacking androgen receptors fail to generate post-meiotic germ cells, therefore, and are infertile. There is also strong evidence that androgens act to ensure appropriate spermiation of mature spermatids. Androgen regulation of spermatogenesis is dependent upon action on the Sertoli cell but recent studies have shown that androgenic stimulation of the peritubular myoid cells is also essential for normal germ cells development. While FSH or androgen alone will both stimulate germ cell development, together they act synergistically to maximise germ cell number. The other hormones/local factors which can regulate spermatogenesis include activins and estrogens although their role in normal physiological regulation of this process needs to be more clearly established. Regulation of spermatogenesis in primates appears to be similar to that in rodents although the role of FSH may be greater. While our knowledge of hormone function

  2. On the formation of germ cells: The good, the bad and the ugly.

    PubMed

    Chuva de Sousa Lopes, Susana M; Roelen, Bernard A J

    2010-03-01

    Mammalian germ cells are powerful cells, the only ones that transmit information to the next generation ensuring the continuation of the species. But "with great power, comes great responsibility", meaning that germ cells are only a few steps away from turning carcinogenic. Despite recent advances little is known about germ cell formation in mammals, predominantly because of the inaccessibility of these cells. Moreover, it is difficult to pin down what in essence is characteristic of a germ cell, as germ cells keep changing place, morphology, expression markers and epigenetic identity. Formation of (primordial) germ cells in primate ES cell cultures would therefore be helpful to identify molecular signalling pathways associated with germ cell differentiation and to study epigenetic changes in germ cells. In addition, the in vitro derivation of functional germ cells from ES cells could be used in combination with therapeutic cloning to generate patient-specific ES cell lines, and can have applications in animal breeding. In this review we present the state-of-the-art on how mouse and human germ cells are formed in vivo (the good), we discuss the link between germ cells, pluripotency and germ cell tumours (the bad) and show that despite continuous progress in trying to differentiate germ cells in vitro (the ugly) the generation of functional germ cells is still a real challenge.

  3. Mechanisms and chemical induction of aneuploidy in rodent germ cells

    SciTech Connect

    Mailhes, J B; Marchetti, F

    2004-10-15

    The objective of this review is to suggest that the advances being made in our understanding of the molecular events surrounding chromosome segregation in non-mammalian and somatic cell models be considered when designing experiments for studying aneuploidy in mammalian germ cells. Accurate chromosome segregation requires the temporal control and unique interactions among a vast array of proteins and cellular organelles. Abnormal function and temporal disarray among these, and others to be inidentified, biochemical reactions and cellular organelles have the potential for predisposing cells to aneuploidy. Although numerous studies have demonstrated that certain chemicals (mainly those that alter microtubule function) can induce aneuploidy in mammalian germ cells, it seems relevant to point out that such data can be influenced by gender, meiotic stage, and time of cell-fixation post-treatment. Additionally, a consensus has not been reached regarding which of several germ cell aneuploidy assays most accurately reflects the human condition. More recent studies have shown that certain kinase, phosphatase, proteasome, and topoisomerase inhibitors can also induce aneuploidy in rodent germ cells. We suggest that molecular approaches be prudently incorporated into mammalian germ cell aneuploidy research in order to eventually understand the causes and mechanisms of human aneuploidy. Such an enormous undertaking would benefit from collaboration among scientists representing several disciplines.

  4. gone early, a novel germline factor, ensures the proper size of the stem cell precursor pool in the Drosophila ovary.

    PubMed

    Matsuoka, Shinya; Gupta, Swati; Suzuki, Emiko; Hiromi, Yasushi; Asaoka, Miho

    2014-01-01

    In order to sustain lifelong production of gametes, many animals have evolved a stem cell-based gametogenic program. In the Drosophila ovary, germline stem cells (GSCs) arise from a pool of primordial germ cells (PGCs) that remain undifferentiated even after gametogenesis has initiated. The decision of PGCs to differentiate or remain undifferentiated is regulated by somatic stromal cells: specifically, epidermal growth factor receptor (EGFR) signaling activated in the stromal cells determines the fraction of germ cells that remain undifferentiated by shaping a Decapentaplegic (Dpp) gradient that represses PGC differentiation. However, little is known about the contribution of germ cells to this process. Here we show that a novel germline factor, Gone early (Goe), limits the fraction of PGCs that initiate gametogenesis. goe encodes a non-peptidase homologue of the Neprilysin family metalloendopeptidases. At the onset of gametogenesis, Goe was localized on the germ cell membrane in the ovary, suggesting that it functions in a peptidase-independent manner in cell-cell communication at the cell surface. Overexpression of Goe in the germline decreased the number of PGCs that enter the gametogenic pathway, thereby increasing the proportion of undifferentiated PGCs. Inversely, depletion of Goe increased the number of PGCs initiating differentiation. Excess PGC differentiation in the goe mutant was augmented by halving the dose of argos, a somatically expressed inhibitor of EGFR signaling. This increase in PGC differentiation resulted in a massive decrease in the number of undifferentiated PGCs, and ultimately led to insufficient formation of GSCs. Thus, acting cooperatively with a somatic regulator of EGFR signaling, the germline factor goe plays a critical role in securing the proper size of the GSC precursor pool. Because goe can suppress EGFR signaling activity and is expressed in EGF-producing cells in various tissues, goe may function by attenuating EGFR signaling

  5. Enhanced Genetic Integrity in Mouse Germ Cells1

    PubMed Central

    Murphey, Patricia; McLean, Derek J.; McMahan, C. Alex; Walter, Christi A.; McCarrey, John R.

    2012-01-01

    ABSTRACT Genetically based diseases constitute a major human health burden, and de novo germline mutations represent a source of heritable genetic alterations that can cause such disorders in offspring. The availability of transgenic rodent systems with recoverable, mutation reporter genes has been used to assess the occurrence of spontaneous point mutations in germline cells. Previous studies using the lacI mutation reporter transgenic mouse system showed that the frequency of spontaneous mutations is significantly lower in advanced male germ cells than in somatic cell types from the same individuals. Here we used this same mutation reporter transgene system to show that female germ cells also display a mutation frequency that is lower than that in corresponding somatic cells and similar to that seen in male germ cells, indicating this is a common feature of germ cells in both sexes. In addition, we showed that statistically significant differences in mutation frequencies are evident between germ cells and somatic cells in both sexes as early as mid-fetal stages in the mouse. Finally, a comparison of the mutation frequency in a general population of early type A spermatogonia with that in a population enriched for Thy-1-positive spermatogonia suggests there is heterogeneity among the early spermatogonial population such that a subset of these cells are predestined to form true spermatogonial stem cells. Taken together, these results support the disposable soma theory, which posits that genetic integrity is normally maintained more stringently in the germ line than in the soma and suggests that this is achieved by minimizing the initial occurrence of mutations in early germline cells and their subsequent gametogenic progeny relative to that in somatic cells. PMID:23153565

  6. Introduction to Germ Cell Development in C. elegans

    PubMed Central

    Pazdernik, Nanette; Schedl, Tim

    2013-01-01

    A central feature of the continuum of life in sexually reproducing metazoans is the cycle of the germline from one generation to the next. This volume describes the cycle of the germline for Caenorhabditis elegans, through chapters that are focused on distinct aspects or processes in germ cell development. Topics include sequential and dependent processes such as specification of germ cells as distinct from somatic cells, sex determination, stem cell proliferative fate versus meiotic development decision, recombination/ progression through meiotic prophase, contemporaneous processes such as gametogenesis, meiotic development and apoptosis, and continuing the cycle into the next generation through fertilization and the oocyte-to-embryo-transition. Throughout germ cell development, translational control and epigenetic mechanisms play prominent roles. These different aspects of germ cell development are seamlessly integrated under optimal conditions and are modified in the different reproductive strategies that are employed by C. elegans under harsh environmental conditions. In this chapter we set the stage by providing a brief background on the C. elegans system and germ cell development, indicating processes in the cycle of the germline that are covered in each chapter. PMID:22872472

  7. gone early, a Novel Germline Factor, Ensures the Proper Size of the Stem Cell Precursor Pool in the Drosophila Ovary

    PubMed Central

    Matsuoka, Shinya; Gupta, Swati; Suzuki, Emiko; Hiromi, Yasushi; Asaoka, Miho

    2014-01-01

    In order to sustain lifelong production of gametes, many animals have evolved a stem cell–based gametogenic program. In the Drosophila ovary, germline stem cells (GSCs) arise from a pool of primordial germ cells (PGCs) that remain undifferentiated even after gametogenesis has initiated. The decision of PGCs to differentiate or remain undifferentiated is regulated by somatic stromal cells: specifically, epidermal growth factor receptor (EGFR) signaling activated in the stromal cells determines the fraction of germ cells that remain undifferentiated by shaping a Decapentaplegic (Dpp) gradient that represses PGC differentiation. However, little is known about the contribution of germ cells to this process. Here we show that a novel germline factor, Gone early (Goe), limits the fraction of PGCs that initiate gametogenesis. goe encodes a non-peptidase homologue of the Neprilysin family metalloendopeptidases. At the onset of gametogenesis, Goe was localized on the germ cell membrane in the ovary, suggesting that it functions in a peptidase-independent manner in cell–cell communication at the cell surface. Overexpression of Goe in the germline decreased the number of PGCs that enter the gametogenic pathway, thereby increasing the proportion of undifferentiated PGCs. Inversely, depletion of Goe increased the number of PGCs initiating differentiation. Excess PGC differentiation in the goe mutant was augmented by halving the dose of argos, a somatically expressed inhibitor of EGFR signaling. This increase in PGC differentiation resulted in a massive decrease in the number of undifferentiated PGCs, and ultimately led to insufficient formation of GSCs. Thus, acting cooperatively with a somatic regulator of EGFR signaling, the germline factor goe plays a critical role in securing the proper size of the GSC precursor pool. Because goe can suppress EGFR signaling activity and is expressed in EGF-producing cells in various tissues, goe may function by attenuating EGFR

  8. Etoposide damages female germ cells in the developing ovary.

    PubMed

    Stefansdottir, Agnes; Johnston, Zoe C; Powles-Glover, Nicola; Anderson, Richard A; Adams, Ian R; Spears, Norah

    2016-08-11

    As with many anti-cancer drugs, the topoisomerase II inhibitor etoposide is considered safe for administration to women in the second and third trimesters of pregnancy, but assessment of effects on the developing fetus have been limited. The purpose of this research was to examine the effect of etoposide on germ cells in the developing ovary. Mouse ovary tissue culture was used as the experimental model, thus allowing us to examine effects of etoposide on all stages of germ cell development in the same way, in vitro. Fetal ovaries from embryonic day 13.5 CD1 mice or neonatal ovaries from postnatal day 0 CD1 mice were cultured with 50-150 ng ml(-1) or 50-200 ng ml(-1) etoposide respectively, concentrations that are low relative to that in patient serum. When fetal ovaries were treated prior to follicle formation, etoposide resulted in dose-dependent damage, with 150 ng ml(-1) inducing a near-complete absence of healthy follicles. In contrast, treatment of neonatal ovaries, after follicle formation, had no effect on follicle numbers and only a minor effect on follicle health, even at 200 ng ml(-1). The sensitivity of female germ cells to etoposide coincided with topoisomerase IIα expression: in the developing ovary of both mouse and human, topoisomerase IIα was expressed in germ cells only prior to follicle formation. Exposure of pre-follicular ovaries, in which topoisomerase IIα expression was germ cell-specific, resulted in a near-complete elimination of germ cells prior to follicle formation, with the remaining germ cells going on to form unhealthy follicles by the end of culture. In contrast, exposure to follicle-enclosed oocytes, which no longer expressed topoisomerase IIα in the germ cells, had no effect on total follicle numbers or health, the only effect seen specific to transitional follicles. Results indicate the potential for adverse effects on fetal ovarian development if etoposide is administered to pregnant women when germ cells are not yet

  9. [Human Primordial Germ Cell Specification--Breakthrough In Culture and Hopes for Therapeutic Utilization].

    PubMed

    Magnúsdóttir, Erna

    2015-10-01

    Germ cells are the precursors to the gametes that carry genetic and epigenetic information between human generations and generate a new individual. Because germ cells are specified early during embryogenesis, at the time of embryo implantation, they are inaccessible for research. Our understanding of their biology has therefore developed slowly since their identification over one hundred years ago. As a result of research into the properties of human and mouse embryonic stem cells and primordial germ cells, scientists have now succeeded in efficiently generating human primordial germ cells in culture by embryonic stem cell and induced pluripotent stem cell culture. In this review we will discuss the state of our knowledge of human primordial germ cells and how research into the pluripotent properties of human and mouse embryonic germ cells has led to this breakthrough. In addition we will discuss the possible utilization of a cell culture system of human primordial germ cells for research into and treatment of germ cell related abnormalities.

  10. Development of a new approach for targeted gene editing in primordial germ cells using TALENs in Xenopus

    PubMed Central

    Nakajima, Keisuke; Yaoita, Yoshio

    2015-01-01

    ABSTRACT A gene of interest can be efficiently modified using transcription activator-like effector nucleases (TALENs) (Christian et al., 2010;Li et al., 2011). However, if a target gene is essential for development, growth and fertility, use of TALENs with high mutagenic activity in F0 frogs could result in developmental disorders or sterility, which would reduce the number of F1 progeny and make F1 phenotypical analysis difficult. We used the 3′ untranslated region of DEADSouth gene (DS-3′) of Xenopus tropicalis to solve this problem, because the addition of the DS-3′ to mRNA is known to induce primordial germ cell (PGC)-specific expression and reduce the stability in somatic cells of mRNA in Xenopus laevis. At first, we inserted the X. tropicalis DS-3′ downstream of the EGFP termination codon and confirmed that the EGFP expression was specifically detected in PGCs for three weeks. Therefore, we inserted the DS-3′ downstream of the termination codon of the TALEN coding sequence. The tyrosinase gene was selected as the target gene for TALEN because the bi-allelic mutation of this gene is easily discernible by the albino phenotype. When fertilized eggs were microinjected with TALEN mRNAs fused to the DS-3′, their sperm and oocytes had a high rate (84–100%) of target-gene modification in contrast to the lower rate (0–45%) of nucleotide alteration observed in somatic cells. PMID:25661867

  11. Development of a new approach for targeted gene editing in primordial germ cells using TALENs in Xenopus.

    PubMed

    Nakajima, Keisuke; Yaoita, Yoshio

    2015-02-06

    A gene of interest can be efficiently modified using transcription activator-like effector nucleases (TALENs) (Christian et al., 2010;Li et al., 2011). However, if a target gene is essential for development, growth and fertility, use of TALENs with high mutagenic activity in F0 frogs could result in developmental disorders or sterility, which would reduce the number of F1 progeny and make F1 phenotypical analysis difficult. We used the 3' untranslated region of DEADSouth gene (DS-3') of Xenopus tropicalis to solve this problem, because the addition of the DS-3' to mRNA is known to induce primordial germ cell (PGC)-specific expression and reduce the stability in somatic cells of mRNA in Xenopus laevis. At first, we inserted the X. tropicalis DS-3' downstream of the EGFP termination codon and confirmed that the EGFP expression was specifically detected in PGCs for three weeks. Therefore, we inserted the DS-3' downstream of the termination codon of the TALEN coding sequence. The tyrosinase gene was selected as the target gene for TALEN because the bi-allelic mutation of this gene is easily discernible by the albino phenotype. When fertilized eggs were microinjected with TALEN mRNAs fused to the DS-3', their sperm and oocytes had a high rate (84-100%) of target-gene modification in contrast to the lower rate (0-45%) of nucleotide alteration observed in somatic cells.

  12. Germ cell tumors of the testicle among aircraft repairmen.

    PubMed

    Ducatman, A M; Conwill, D E; Crawl, J

    1986-10-01

    A cluster of testicular germ cell tumors occurred among 3 of 153 white men who worked in a shop engaged in repair of exterior surfaces and electrical components of the airframes of F4 Phantom Jet aircraft. Evaluation of an occupationally identical shop at a second F4 rework facility at which there had been no previous reports of excess neoplasms revealed 4 additional men with a history of testicular germ cell tumors (p less than 0.01, Poisson, compared to the expected number of cases based on national incidence rates). Our investigation raises but does not prove a hypothesis of association between subsequent development of testicular germ cell cancer and history of extensive exposure to a mixture containing dimethylformamide, which had been used in F4 repair work at these facilities in the 1960s and 1970s. This represents the first report of 2 corresponding mini-epidemics of testicular tumors among workers in occupationally identical industrial settings.

  13. Giant Mediastinal Germ Cell Tumour: An Enigma of Surgical Consideration

    PubMed Central

    Ali, Nurayub Mohd; Azizan, Nornazirah; Zakaria, Andee Dzulkarnaen; Rahman, Mohd Ramzisham Abdul

    2016-01-01

    We present a case of 16-year-old male, who was referred from private centre for dyspnoea, fatigue, and orthopnea. The chest radiograph revealed complete opacification of left chest which was confirmed by computed tomography as a large left mediastinal mass measuring 14 × 15 × 18 cm. The diagnostic needle core biopsy revealed mixed germ cell tumour with possible combination of embryonal carcinoma, yolk sac, and teratoma. After 4 cycles of neoadjuvant BEP regime, there was initial response of tumour markers but not tumour bulk. Instead of classic median sternotomy or clamshell incision, posterolateral approach with piecemeal manner was chosen. Histology confirmed mixed germ cell tumour with residual teratomatous component without yolk sac or embryonal carcinoma component. Weighing 3.5 kg, it is one of the largest mediastinal germ cell tumours ever reported. We describe this rare and gigantic intrathoracic tumour and discuss the spectrum of surgical approach and treatment of this exceptional tumour. PMID:27807495

  14. A functional genomic screen in planarians identifies novel regulators of germ cell development.

    PubMed

    Wang, Yuying; Stary, Joel M; Wilhelm, James E; Newmark, Phillip A

    2010-09-15

    Germ cells serve as intriguing examples of differentiated cells that retain the capacity to generate all cell types of an organism. Here we used functional genomic approaches in planarians to identify genes required for proper germ cell development. We conducted microarray analyses and in situ hybridization to discover and validate germ cell-enriched transcripts, and then used RNAi to screen for genes required for discrete stages of germ cell development. The majority of genes we identified encode conserved RNA-binding proteins, several of which have not been implicated previously in germ cell development. We also show that a germ cell-specific subunit of the conserved transcription factor CCAAT-binding protein/nuclear factor-Y is required for maintaining spermatogonial stem cells. Our results demonstrate that conserved transcriptional and post-transcriptional mechanisms regulate germ cell development in planarians. These findings suggest that studies of planarians will inform our understanding of germ cell biology in higher organisms.

  15. A functional genomic screen in planarians identifies novel regulators of germ cell development

    PubMed Central

    Wang, Yuying; Stary, Joel M.; Wilhelm, James E.; Newmark, Phillip A.

    2010-01-01

    Germ cells serve as intriguing examples of differentiated cells that retain the capacity to generate all cell types of an organism. Here we used functional genomic approaches in planarians to identify genes required for proper germ cell development. We conducted microarray analyses and in situ hybridization to discover and validate germ cell-enriched transcripts, and then used RNAi to screen for genes required for discrete stages of germ cell development. The majority of genes we identified encode conserved RNA-binding proteins, several of which have not been implicated previously in germ cell development. We also show that a germ cell-specific subunit of the conserved transcription factor CCAAT-binding protein/nuclear factor-Y is required for maintaining spermatogonial stem cells. Our results demonstrate that conserved transcriptional and post-transcriptional mechanisms regulate germ cell development in planarians. These findings suggest that studies of planarians will inform our understanding of germ cell biology in higher organisms. PMID:20844018

  16. Klinefelter Syndrome with Poor Risk Extragonadal Germ Cell Tumor.

    PubMed

    Konheim, Jeremy A; Israel, Jonathan A; Delacroix, Scott E

    2017-01-01

    Germ cell tumors are the most common malignancy in men aged 15-35 years old, with a small percentage presenting in an extragonadal location. These tumors are seldom identified in the gastrointestinal tract. There is increased risk of extragonadal germ cell tumors (EGCT) in men with Klinefelter syndrome (KS). We report a rare case of a 37-year-old male with KS and EGCT discovered in the duodenum and pelvis. After treatment with Bleomycin-Etoposide-Cisplatin (BEP), he developed growing teratoma syndrome (GTS) and myelodysplasia. Despite surgical excision of the pelvic growing teratoma, he unfortunately died secondary to complications of severe bone marrow suppression.

  17. Sertoli cell condition medium can induce germ like cells from bone marrow derived mesenchymal stem cells.

    PubMed

    Monfared, Mahdieh Hajian; Minaee, Bagher; Rastegar, Tayebeh; Khrazinejad, Ebrahim; Barbarestani, Mohammad

    2016-11-01

    Although many researchers have confirmed induction of germ cells from bone marrow mesenchymal stem cells (BMMSCs), there are no reports that confirm spontaneous differentiation of germ cells from BMMSCs. In this study, we have evaluated the effect of adult Sertoli cell condition medium (SCCM) as a mutative factor in the induction of germ cells from BMMSCs. BMMSCs were collected from the bone marrow of 6-8-week old NMRI mice and their mesenchymal entities were proven using superficial markers (expression of CD44 and CD73 and non-expresion of CD45 and CD11b) by fow cytometry. Their multi-potential entities were proved with differentiation to osteogenic and adipogenic cells for 21 days. Also isolated Sertoli cells were enriched using lectin coated plates and Sertoli cell condition medium (SCCM) was collected. Sertoli cells were identified by immunocytochemistry and Vimentin marker. The cells were then differentiated into germ cells with SCCM for 2 weeks. Finally induced cells were evaluated by RT-PCR and immunocytochemistry. Differentiation of mesenchymal stem cells to osteoblast and adipocyte showed their multi-potential property. Expression of CD44 and CD73 and non-expression of CD45 and CD11b confirmed mesenchyme cells. Immunocytochemistry and RT-PCR results showed expression of germ cells specific marker (Mvh). This study confirmed the effect of SCCM as a motivational factor that can used for differentiation of germ cells from BMMSCs.

  18. Sertoli cell condition medium can induce germ like cells from bone marrow derived mesenchymal stem cells

    PubMed Central

    Monfared, Mahdieh Hajian; Minaee, Bagher; Rastegar, Tayebeh; Khrazinejad, Ebrahim; Barbarestani, Mohammad

    2016-01-01

    Objective(s): Although many researchers have confirmed induction of germ cells from bone marrow mesenchymal stem cells (BMMSCs), there are no reports that confirm spontaneous differentiation of germ cells from BMMSCs. In this study, we have evaluated the effect of adult Sertoli cell condition medium (SCCM) as a mutative factor in the induction of germ cells from BMMSCs. Materials and Methods: BMMSCs were collected from the bone marrow of 6-8-week old NMRI mice and their mesenchymal entities were proven using superficial markers (expression of CD44 and CD73 and non-expresion of CD45 and CD11b) by fow cytometry. Their multi-potential entities were proved with differentiation to osteogenic and adipogenic cells for 21 days. Also isolated Sertoli cells were enriched using lectin coated plates and Sertoli cell condition medium (SCCM) was collected. Sertoli cells were identified by immunocytochemistry and Vimentin marker. The cells were then differentiated into germ cells with SCCM for 2 weeks. Finally induced cells were evaluated by RT-PCR and immunocytochemistry. Results: Differentiation of mesenchymal stem cells to osteoblast and adipocyte showed their multi-potential property. Expression of CD44 and CD73 and non-expression of CD45 and CD11b confirmed mesenchyme cells. Immunocytochemistry and RT-PCR results showed expression of germ cells specific marker (Mvh). Conclusion: This study confirmed the effect of SCCM as a motivational factor that can used for differentiation of germ cells from BMMSCs. PMID:27917274

  19. Germ cell DNA quantification shortly after IR laser radiation.

    PubMed

    Bermúdez, D; Carrasco, F; Diaz, F; Perez-de-Vargas, I

    1991-01-01

    The immediate effect of IR laser radiation on rat germ cells was studied by cytophotometric quantification of the nuclear DNA content in testicular sections. Two different levels of radiation were studied: one according to clinical application (28.05 J/cm2) and another known to increase the germ cell number (46.80 J/cm2). The laser beam induced changes in the germ cell DNA content depending on the cell type, the cell cycle phase and the doses of radiation energy applied. Following irradiation at both doses the percentage of spermatogonia showing a 4c DNA content was increased, while the percentage of these with a 2c DNA content was decreased. Likewise, the percentages of primary spermatocytes with a DNA content equal to 4c (at 28.05 J/cm2), between 2c and 4c (at 46.80 J/cm2) and higher than 4c (at both doses) were increased. No change in the mean spermatid DNA content was observed. Nevertheless, at 46.80 J/cm2 the percentages of elongated spermatids with a c or 2c DNA content differed from the controls. Data show that, even at laser radiation doses used in therapy, the germ cell DNA content is increased shortly after IR laser radiation.

  20. Cell cycle analysis of fetal germ cells during sex differentiation in mice

    PubMed Central

    Spiller, Cassy; Wilhelm, Dagmar; Koopman, Peter

    2009-01-01

    Background information. Primordial germ cells in developing male and female gonads are responsive to somatic cell cues that direct their sex-specific differentiation into functional gametes. The first divergence of the male and female pathways is a change in cell cycle state observed from 12.5 dpc (days post coitum) in mice. At this time XY and XX germ cells cease mitotic division and enter G1/G0 arrest and meiosis prophase I respectively. Aberrant cell cycle regulation at this time can lead to disrupted ovarian development, germ cell apoptosis, reduced fertility and/or the formation of germ cell tumours. Results. In order to unravel the mechanisms utilized by germ cells to achieve and maintain the correct cell cycle states, we analysed the expression of a large number of cell cycle genes in purified germ cells across the crucial time of sex differentiation. Our results revealed common signalling for both XX and XY germ cell survival involving calcium signalling. A robust mechanism for apoptosis and checkpoint control was observed in XY germ cells, characterized by p53 and Atm (ataxia telangiectasia mutated) expression. Additionally, a member of the retinoblastoma family and p21 were identified, linking these factors to XY germ cell G1/G0 arrest. Lastly, in XX germ cells we observed a down-regulation of genes involved in both G1- and G2-phases of the cell cycle consistent with their entry into meiosis. Conclusion. The present study has provided a detailed analysis of cell cycle gene expression during fetal germ cell development and identified candidate factors warranting further investigation in order to understand cases of aberrant cell cycle control in these specialized cells. PMID:19419345

  1. Childhood Central Nervous System Germ Cell Tumors Treatment (PDQ®)—Patient Version

    Cancer.gov

    Childhood central nervous system (CNS) germ cell tumors form from germ cells (a type of cell that forms as a fetus develops and later becomes sperm in the testicles or eggs in the ovaries). Learn about the signs, tests to diagnose, and treatment of pediatric germ cell tumors in the brain in this expert-reviewed summary.

  2. [Effects of formaldehyde on germ cells of male mice].

    PubMed

    Tang, Mingde; Xie, Ying; Yi, Yizhen; Wang, Wei

    2003-11-01

    General toxicity and genetic materials damage of formaldehyde on germ cells in different stages was studied. In order to discover the toxicity mechanism of formaldehyde on germ cells and the biomarkers of effect after the presence of damage in germ cells and the estimation index, the relationships between the damage of germ cells and the MDA, SDH activity and Cu and Zn. in testicle tissue were investigated. Male mice exposed to formaldehyde by i.p. for 5 days. Formaldehyde doses were: 0.20 mg/kg, 2.00 mg/kg, 20.00 mg/kg. Mice were killed at the 6th day and the 14th day. HE staining was used to study the pathological changes happened in testicle tissue. In order to study the changes in sperm, the sperms and the abnormality of the sperm's heads were observed. In order to study the damage of the genetic material in the germ cells, the frequencies of sister chromosome exchanges and the frequencies of MN cells were studied. MDA was measured by MDA diagnosis box. Copper and zinc were determined by FAAS. US was used to determine the SDH activity in serum and testicle tissue. The results showed that: The main pathological changes in testicle tissue of formaldehyde groups were degeneration; The sperm quantity was decreased and the sperm heads deformation ratio was increased in all formaldehyde groups; There were a significant increase of MN ratio in early spermatogenic cells and SCE ratio in medial and high dose groups; The MDA in testicle tissue significant increased in high dose group. The SDH activity in testicle tissue was declined in all formaldehyde groups; There were a significant decline of copper and zinc in testicle tissue in high dose group. It is suggested that: Formaldehyde could induce genetic materials in spermatogone, primary spermatocyte and caused degeneration and necrosis in secondary spermatocyte, spermatogenic cell, sperm; The damage of LPO, decline of copper and zinc and SDH activity in mice's testicle tissue could be caused by formaldehyde; The effect

  3. Functional analysis of the Drosophila embryonic germ cell transcriptome by RNA interference.

    PubMed

    Jankovics, Ferenc; Henn, László; Bujna, Ágnes; Vilmos, Péter; Spirohn, Kerstin; Boutros, Michael; Erdélyi, Miklós

    2014-01-01

    In Drosophila melanogaster, primordial germ cells are specified at the posterior pole of the very early embryo. This process is regulated by the posterior localized germ plasm that contains a large number of RNAs of maternal origin. Transcription in the primordial germ cells is actively down-regulated until germ cell fate is established. Bulk expression of the zygotic genes commences concomitantly with the degradation of the maternal transcripts. Thus, during embryogenesis, maternally provided and zygotically transcribed mRNAs determine germ cell development collectively. In an effort to identify novel genes involved in the regulation of germ cell behavior, we carried out a large-scale RNAi screen targeting both maternal and zygotic components of the embryonic germ line transcriptome. We identified 48 genes necessary for distinct stages in germ cell development. We found pebble and fascetto to be essential for germ cell migration and germ cell division, respectively. Our data uncover a previously unanticipated role of mei-P26 in maintenance of embryonic germ cell fate. We also performed systematic co-RNAi experiments, through which we found a low rate of functional redundancy among homologous gene pairs. As our data indicate a high degree of evolutionary conservation in genetic regulation of germ cell development, they are likely to provide valuable insights into the biology of the germ line in general.

  4. Functional Analysis of the Drosophila Embryonic Germ Cell Transcriptome by RNA Interference

    PubMed Central

    Bujna, Ágnes; Vilmos, Péter; Spirohn, Kerstin; Boutros, Michael; Erdélyi, Miklós

    2014-01-01

    In Drosophila melanogaster, primordial germ cells are specified at the posterior pole of the very early embryo. This process is regulated by the posterior localized germ plasm that contains a large number of RNAs of maternal origin. Transcription in the primordial germ cells is actively down-regulated until germ cell fate is established. Bulk expression of the zygotic genes commences concomitantly with the degradation of the maternal transcripts. Thus, during embryogenesis, maternally provided and zygotically transcribed mRNAs determine germ cell development collectively. In an effort to identify novel genes involved in the regulation of germ cell behavior, we carried out a large-scale RNAi screen targeting both maternal and zygotic components of the embryonic germ line transcriptome. We identified 48 genes necessary for distinct stages in germ cell development. We found pebble and fascetto to be essential for germ cell migration and germ cell division, respectively. Our data uncover a previously unanticipated role of mei-P26 in maintenance of embryonic germ cell fate. We also performed systematic co-RNAi experiments, through which we found a low rate of functional redundancy among homologous gene pairs. As our data indicate a high degree of evolutionary conservation in genetic regulation of germ cell development, they are likely to provide valuable insights into the biology of the germ line in general. PMID:24896584

  5. Stem cells and germ cells: microRNA and gene expression signatures.

    PubMed

    Dyce, Paul William; Toms, Derek; Li, Julang

    2010-04-01

    The study of primordial germ cell development in vivo is hampered by their low numbers and inaccessibility. Recent research has shown the ability of embryonic and adult stem cells to differentiate into primordial germ cells and more mature gametes and this generation of germ cells in vitro may be an attractive model for their study. One of the biggest challenges facing in vitro differentiation of stem cells into primordial germ cells is the lack of markers to clearly distinguish the two. As both cell types originate early in embryonic development they share many pluripotent markers such as OCT4, VASA, FRAGILIS, and NANOG. Genome wide microarray profiling has been used to identify transcriptome patterns unique to primordial germ cells. A more thorough analysis of the temporal and quantitative expression of a panel of genes may be more robust in distinguishing these two cell populations. MicroRNAs, short RNA molecules that have been shown to regulate translation through interactions with mRNA transcripts, have also recently come under investigation for the role they may play in pluripotency. Attempts to elucidate key microRNAs responsible for both stem cell and primordial germ cell characteristics have recently been undertaken. Unique microRNAs, either individually or as global profiles, may also help to distinguish differentiated primordial germ cells from stem cells in vitro. This review will examine gene expression and microRNA signatures in stem cells and germ cells as ways to distinguish these closely related cell types.

  6. HMG-CoA reductase guides migrating primordial germ cells.

    PubMed

    Van Doren, M; Broihier, H T; Moore, L A; Lehmann, R

    1998-12-03

    The enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase is best known for catalysing a rate-limiting step in cholesterol biosynthesis, but it also participates in the production of a wide variety of other compounds. Some clinical benefits attributed to inhibitors of HMG-CoA reductase are now thought to be independent of any serum cholesterol-lowering effect. Here we describe a new cholesterol-independent role for HMG-CoA reductase, in regulating a developmental process: primordial germ cell migration. We show that in Drosophila this enzyme is highly expressed in the somatic gonad and that it is necessary for primordial germ cells to migrate to this tissue. Misexpression of HMG-CoA reductase is sufficient to attract primordial germ cells to tissues other than the gonadal mesoderm. We conclude that the regulated expression of HMG-CoA reductase has a critical developmental function in providing spatial information to guide migrating primordial germ cells.

  7. Curing metastatic cancer: lessons from testicular germ-cell tumours.

    PubMed

    Masters, John R W; Köberle, Beate

    2003-07-01

    Most metastatic cancers are fatal. More than 80% of patients with metastatic testicular germ-cell tumours (TGCTs), however, can be cured using cisplatin-based combination chemotherapy. Why are TGCTs more sensitive to chemotherapeutics than most other tumour types? Answers to this question could lead to new treatments for metastatic cancers.

  8. Declaring the Existence of Human Germ-Cell Mutagens

    EPA Science Inventory

    After more than 80 years of searching for human germ-cell mutagens, I think that sufficient evidence already exists for a number of agents to be so considered, and definitive confirmation seems imminent due to the application ofrecently developed genomic techniques. In preparatio...

  9. Declaring the Existence of Human Germ-Cell Mutagens

    EPA Science Inventory

    After more than 80 years of searching for human germ-cell mutagens, I think that sufficient evidence already exists for a number of agents to be so considered, and definitive confirmation seems imminent due to the application ofrecently developed genomic techniques. In preparatio...

  10. Delayed BMP4 exposure increases germ cell differentiation in mouse embryonic stem cells.

    PubMed

    Talaei-Khozani, Tahereh; Zarei Fard, Nehleh; Bahmanpour, Soghra; Jaberipour, Mansoureh; Hosseini, Ahmah; Esmaeilpour, Tahereh

    2014-01-01

    Fate mapping studies have revealed that bone morphogenetic protein 4 (BMP4) signaling has a key role in segregation of primordial germ cells from proximal epiblast. Adding BMP4 to the culture media of embryonic stem (ES) cells could induce expression of germ cell markers; however, to provide a desired number of germ cells has remained a challenge. In the current study, we intended to establish an in vitro system to obtain reliable germ cells derived from ES cells. Differentiation was induced in ES cells via embryoid body (EB) and monolayer culture system. Cells were cultured with BMP4 from the beginning (++BMP4) or after 48 hours (+BMP4) of culturing for five days. The cultures were assessed for alkaline phosphatase (ALP) activity, expression of Oct4, Mvh and c-kit. In EB culture protocol, the expression of Mvh, Oct4 and ALP activity significantly increased in +BMP4 culture condition, but a significant down-regulation in the expression of germ cell markers was shown in ++BMP4 condition compared with the control group. Parallel differentiation experiments using monolayer culture system indicated the number of putative germ cells did not change. In the current study, we compared two differentiation methods (EB and monolayer) to achieve an optimal germ cell production. The EBs with a short exposure time period to BMP4, showing typical characteristics of germ cells. Therefore, our approach provides a strategy for the production of germline cells from ES cells.

  11. The pathology of late recurrence of testicular germ cell tumors.

    PubMed

    Michael, H; Lucia, J; Foster, R S; Ulbright, T M

    2000-02-01

    A total of 91 men had histologically documented late recurrences of testicular germ cell tumors characterized by a complete response to treatment with a subsequent disease-free interval of at least 2 years and no evidence of a second primary lesion. Ninety percent of the patients for whom information was available received chemotherapy shortly after their initial diagnosis of testicular germ cell tumors; most of the other patients were known to have stage I disease initially. Overall, 60% of patients had teratoma in their late recurrences, including 20 patients (22%) in whom teratoma was the only element. Thus, teratoma was the most common type of neoplasm in late recurrences. Excluding teratoma coexisting with other types of neoplasms, yolk sac tumor was the most frequent type of tumor in patients with late recurrence. It occurred in 47% of patients, either alone or with teratoma, another nonteratomatous germ cell tumor type, or a "nongerm cell malignant tumor." Unusual types of yolk sac tumor, including glandular, parietal, clear cell, and pleomorphic patterns, were seen frequently in late recurrences and often raised differential diagnostic problems with "nongerm cell" carcinomas. A smaller number of late recurrences consisted of other types of neoplasms. Twenty percent of patients with late recurrence had a nonteratomatous germ cell tumor other than yolk sac tumor, either alone, with yolk sac tumor, or with a "nongerm cell malignant tumor." Most of these nonteratomatous germ cell tumors other than yolk sac tumor were embryonal carcinoma, although rarely seminoma and choriocarcinoma were encountered. "Nongerm cell malignant tumors," including both sarcomas and carcinomas of various types, occurred in 23% of late-recurrence patients, either alone or with a nonteratomatous germ cell tumor. Late recurrences were seen in many different sites in these patients, including the retroperitoneum, abdomen, pelvis, liver, mediastinum, lung, bone (femur, vertebra, and rib

  12. DNA Analysis in Samples From Younger Patients With Germ Cell Tumors and Their Parents or Siblings

    ClinicalTrials.gov

    2016-10-05

    Childhood Malignant Ovarian Germ Cell Tumor; Childhood Malignant Testicular Germ Cell Tumor; Ovarian Choriocarcinoma; Ovarian Embryonal Carcinoma; Ovarian Mixed Germ Cell Tumor; Ovarian Teratoma; Ovarian Yolk Sac Tumor; Testicular Choriocarcinoma; Testicular Embryonal Carcinoma; Testicular Seminoma; Testicular Teratoma; Testicular Yolk Sac Tumor

  13. Germ cells influence cord formation and Leydig cell gene expression during mouse testis development.

    PubMed

    Rios-Rojas, Clarissa; Spiller, Cassy; Bowles, Josephine; Koopman, Peter

    2016-04-01

    It is widely accepted that, during the development of testes in the mammalian embryo, male germ cells are influenced by signals from the surrounding somatic cells, but not vice versa, so that germ cells are dispensable for the formation of testes. We now demonstrate that development of the mouse fetal testis is compromised in the absence of germ cells. Using two- and three-dimensional imaging techniques, we reveal that W(e)/W(e) mutant testes devoid of germ cells have misshapen and poorly organized cords. We also found that mutant gonads have fewer Sertoli cells than normal and that the Leydig cells express key markers at higher than normal levels. These observations point to the existence of germ cell-derived signals that directly or indirectly affect the Sertoli and Leydig cell populations, and provide a new paradigm for the organogenesis of the mammalian testes. © 2015 Wiley Periodicals, Inc.

  14. Generation of male differentiated germ cells from various types of stem cells.

    PubMed

    Hou, Jingmei; Yang, Shi; Yang, Hao; Liu, Yang; Liu, Yun; Hai, Yanan; Chen, Zheng; Guo, Ying; Gong, Yuehua; Gao, Wei-Qiang; Li, Zheng; He, Zuping

    2014-06-01

    Infertility is a major and largely incurable disease caused by disruption and loss of germ cells. It affects 10-15% of couples, and male factor accounts for half of the cases. To obtain human male germ cells 'especially functional spermatids' is essential for treating male infertility. Currently, much progress has been made on generating male germ cells, including spermatogonia, spermatocytes, and spermatids, from various types of stem cells. These germ cells can also be used in investigation of the pathology of male infertility. In this review, we focused on advances on obtaining male differentiated germ cells from different kinds of stem cells, with an emphasis on the embryonic stem (ES) cells, the induced pluripotent stem (iPS) cells, and spermatogonial stem cells (SSCs). We illustrated the generation of male differentiated germ cells from ES cells, iPS cells and SSCs, and we summarized the phenotype for these stem cells, spermatocytes and spermatids. Moreover, we address the differentiation potentials of ES cells, iPS cells and SSCs. We also highlight the advantages, disadvantages and concerns on derivation of the differentiated male germ cells from several types of stem cells. The ability of generating mature and functional male gametes from stem cells could enable us to understand the precise etiology of male infertility and offer an invaluable source of autologous male gametes for treating male infertility of azoospermia patients. © 2014 Society for Reproduction and Fertility.

  15. Regulative germ cell specification in axolotl embryos: a primitive trait conserved in the mammalian lineage.

    PubMed Central

    Johnson, Andrew D; Crother, Brian; White, Mary E; Patient, Roger; Bachvarova, Rosemary F; Drum, Matthew; Masi, Thomas

    2003-01-01

    How germ cells are specified in the embryos of animals has been a mystery for decades. Unlike most developmental processes, which are highly conserved, embryos specify germ cells in very different ways. Curiously, in mouse embryos germ cells are specified by extracellular signals; they are not autonomously specified by maternal germ cell determinants (germ plasm), as are the germ cells in most animal model systems. We have developed the axolotl (Ambystoma mexicanum), a salamander, as an experimental system, because classic experiments have shown that the germ cells in this species are induced by extracellular signals in the absence of germ plasm. Here, we provide evidence that the germ cells in axolotls arise from naive mesoderm in response to simple inducing agents. In addition, by analysing the sequences of axolotl germ-cell-specific genes, we provide evidence that mice and urodele amphibians share a common mechanism of germ cell development that is ancestral to tetrapods. Our results imply that germ plasm, as found in species such as frogs and teleosts, is the result of convergent evolution. We discuss the evolutionary implications of our findings. PMID:14511484

  16. Unique Aspects of Transcription Regulation in Male Germ Cells

    PubMed Central

    White-Cooper, Helen; Davidson, Irwin

    2011-01-01

    Spermatogenesis is a complex and ordered differentiation process in which the spermatogonial stem cell population gives rise to primary spermatocytes that undergo two successive meiotic divisions followed by a major biochemical and structural reorganization of the haploid cells to generate mature elongate spermatids. The transcriptional regulatory programs that orchestrate this process have been intensively studied in model organisms such as Drosophila melanogaster and mouse. Genetic and biochemical approaches have identified the factors involved and revealed mechanisms of action that are unique to male germ cells. In a well-studied example, cofactors and pathways distinct from those used in somatic tissues mediate the action of CREM in male germ cells. But perhaps the most striking feature concerns the paralogs of somatically expressed transcription factors and of components of the general transcription machinery that act in distinct regulatory mechanisms in both Drosophila and murine spermatogenesis. PMID:21555408

  17. Adeno-associated virus (AAV)-mediated transduction of male germ line stem cells results in transgene transmission after germ cell transplantation.

    PubMed

    Honaramooz, Ali; Megee, Susan; Zeng, Wenxian; Destrempes, Margret M; Overton, Susan A; Luo, Jinping; Galantino-Homer, Hannah; Modelski, Mark; Chen, Fangping; Blash, Stephen; Melican, David T; Gavin, William G; Ayres, Sandra; Yang, Fang; Wang, P Jeremy; Echelard, Yann; Dobrinski, Ina

    2008-02-01

    We explored whether exposure of mammalian germ line stem cells to adeno-associated virus (AAV), a gene therapy vector, would lead to stable transduction and transgene transmission. Mouse germ cells harvested from experimentally induced cryptorchid donor testes were exposed in vitro to AAV vectors carrying a GFP transgene and transplanted to germ cell-depleted syngeneic recipient testes, resulting in colonization of the recipient testes by transgenic donor cells. Mating of recipient males to wild-type females yielded 10% transgenic offspring. To broaden the approach to nonrodent species, AAV-transduced germ cells from goats were transplanted to recipient males in which endogenous germ cells had been depleted by fractionated testicular irradiation. Transgenic germ cells colonized recipient testes and produced transgenic sperm. When semen was used for in vitro fertilization (IVF), 10% of embryos were transgenic. Here, we report for the first time that AAV-mediated transduction of mammalian germ cells leads to transmission of the transgene through the male germ line. Equally important, this is also the first report of transgenesis via germ cell transplantation in a nonrodent species, a promising approach to generate transgenic large animal models for biomedical research.

  18. Wheat germ systems for cell-free protein expression.

    PubMed

    Harbers, Matthias

    2014-08-25

    Cell-free protein expression plays an important role in biochemical research. However, only recent developments led to new methods to rapidly synthesize preparative amounts of protein that make cell-free protein expression an attractive alternative to cell-based methods. In particular the wheat germ system provides the highest translation efficiency among eukaryotic cell-free protein expression approaches and has a very high success rate for the expression of soluble proteins of good quality. As an open in vitro method, the wheat germ system is a preferable choice for many applications in protein research including options for protein labeling and the expression of difficult-to-express proteins like membrane proteins and multiple protein complexes. Here I describe wheat germ cell-free protein expression systems and give examples how they have been used in genome-wide expression studies, preparation of labeled proteins for structural genomics and protein mass spectroscopy, automated protein synthesis, and screening of enzymatic activities. Future directions for the use of cell-free expression methods are discussed.

  19. Very Small Embryonic-Like Stem Cells: A Potential Developmental Link Between Germinal Lineage and Hematopoiesis in Humans.

    PubMed

    Virant-Klun, Irma

    2016-01-15

    It has been suggested that hematopoietic stem/progenitor cells (HSPCs) could become specified from a population of migrating primordial germ cells (PGCs), precursors of gametes, during embryogenesis. Some recent experimental data demonstrated that the cell population that is usually considered to be PGCs, moving toward the gonadal ridges of an embryo, contains a subset of cells coexpressing several germ cell and hematopoietic markers and possessing hematopoietic activity. Experimental data showed that bone morphogenetic protein 4 (BMP4) generates PGCs from mouse bone marrow-derived pluripotent stem cells. Interestingly, functional reproductive hormone receptors have been identified in HSPCs, thus indicating their potential role in reproductive function. Several reports have demonstrated fertility restoration and germ cell generation after bone marrow transplantation in both animal models and humans. A potential link between HSPCs and germinal lineage might be represented by very small embryonic-like stem cells (VSELs), which have been found in adult human bone marrow, peripheral blood, and umbilical cord blood, express a specific pattern of pluripotency, germinal lineage, and hematopoiesis, and are proposed to persist in adult tissues and organs from the embryonic period of life. Stem cell populations, similar to VSELs, expressing several genes related to pluripotency and germinal lineage, especially to PGCs, have been discovered in adult human reproductive organs, ovaries and testicles, and were related to primitive germ cell-like cell development in vitro, thus supporting the idea of VSELs as a potential link between germinal lineage and hematopoiesis.

  20. Porcine reproductive and respiratory syndrome virus replicates in testicular germ cells, alters spermatogenesis, and induces germ cell death by apoptosis.

    PubMed Central

    Sur, J H; Doster, A R; Christian, J S; Galeota, J A; Wills, R W; Zimmerman, J J; Osorio, F A

    1997-01-01

    Like other arteriviruses, porcine reproductive and respiratory syndrome virus (PRRSV) is shed in semen, a feature that is critical for the venereal transmission of this group of viruses. In spite of its epidemiological importance, little is known of the association of PRRSV or other arteriviruses with gonadal tissues. We experimentally infected a group of boars with PRRSV 12068-96, a virulent field strain. By combined use of in situ hybridization and immunohistochemistry, we detected infection by PRRSV in the testes of these boars. The PRRSV testicular replication in testis centers on two types of cells: (i) epithelial germ cells of the seminiferous tubules, primarily spermatids and spermatocytes, and (ii) macrophages, which are located in the interstitium of the testis. Histopathologically, hypospermatogenesis, formation of multinucleated giant cells (MGCs), and abundant germ cell depletion and death were observed. We obtained evidence that such germ cell death occurs by apoptosis, as determined by a characteristic histologic pattern and evidence of massive DNA fragmentation detected in situ (TUNEL [terminal deoxynucleotidyltransferase-mediated digoxigenin-UTP nick end labeling] assay). Simultaneously with these testicular alterations, we observed that there is a significant increase in the number of immature sperm cells (mainly MGCs, spermatids, and spermatocytes) in the ejaculates of the PRRSV-inoculated boars and that these cells are infected with PRRSV. Our results indicate that PRRSV may infect target cells other than macrophages, that these infected cells can be primarily responsible for the excretion of infectious PRRSV in semen, and that PRRSV induces apoptosis in these germ cells in vivo. PMID:9371575

  1. Prmt5 is required for germ cell survival during spermatogenesis in mice

    PubMed Central

    Wang, Yanbo; Zhu, Tianxiang; Li, Qiuling; Liu, Chunyi; Han, Feng; Chen, Min; Zhang, Lianjun; Cui, Xiuhong; Qin, Yan; Bao, Shilai; Gao, Fei

    2015-01-01

    During germ cell development, epigenetic modifications undergo extensive remodeling. Abnormal epigenetic modifications usually result in germ cell loss and reproductive defect. Prmt5 (Protein arginine methyltransferase 5) encodes a protein arginine methyltransferase which has been demonstrated to play important roles in germ cell development during embryonic stages. In the present study, we found that Prmt5 was also abundantly expressed in male germ cells after birth. Inactivation of this gene by crossing with Stra8-Cre transgenic mice resulted in germ cell loss during spermatogenesis. Further study revealed that the germ cell development was grossly normal before P10. However, most of the germ cells in Prmt5Δ/f; Stra8-Cre mice were blocked at meiotic stage. The expression of meiosis associated genes was reduced in Prmt5Δ/f; Stra8-Cre testes compared to control testes at P10. γH2AX was detected in sex body of control germ cells at P12, whereas multiple foci were observed in Prmt5-deficient germ cells. Further study revealed that H4R3me2s was virtually absent in germ cells after Prmt5 inactivation. The results of this study indicate that Prmt5 also plays important roles in germ cell development during spermatogenesis. PMID:26072710

  2. Chlorambucil effectively induces deletion mutations in mouse germ cells.

    PubMed Central

    Russell, L B; Hunsicker, P R; Cacheiro, N L; Bangham, J W; Russell, W L; Shelby, M D

    1989-01-01

    The chemotherapeutic agent chlorambucil was found to be more effective than x-rays or any chemical investigated to date in inducing high yields of mouse germ-line mutations that appear to be deletions or other structural changes. Induction of mutations involving seven specific loci was studied after exposures of various male germ-cell stages to chlorambucil at 10-25 mg/kg. A total of 60,750 offspring was scored. Mutation rates in spermatogonial stem cells were not significantly increased over control values; this negative result is not attributable to selective elimination of mutant cells. Mutations were, however, clearly induced in treated post-stem-cell stages, among which marked variations in mutational response were found. Maximum yield occurred after exposure of early spermatids, with approximately 1% of all offspring carrying a specific-locus mutation in the 10 mg/kg group. The stage-response pattern for chlorambucil differs from that of all other chemicals investigated to date in the specific-locus test. Thus far, all but one of the tested mutations induced by chlorambucil in post-stem-cell stages have been proved deletions or other structural changes by genetic, cytogenetic, and/or molecular criteria. Deletion mutations have recently been useful for molecular mapping and for structure-function correlations of genomic regions. For generating presumed large-lesion germ-line mutations at highest frequencies, chlorambucil may be the mutagen of choice. Images PMID:2726748

  3. Intraperitoneal germ cell transplantation in the Nile tilapia Oreochromis niloticus.

    PubMed

    Farlora, Rodolfo; Hattori-Ihara, Shoko; Takeuchi, Yukata; Hayashi, Makoto; Octavera, Anna; Alimuddin; Yoshizaki, Goro

    2014-06-01

    Germ cell transplantation offers promising applications in finfish aquaculture and the preservation of endangered species. Here, we describe an intraperitoneal spermatogonia transplantation procedure in the Nile tilapia Oreochromis niloticus. Through histological analysis of early gonad development, we first determined the best suitable stage at which exogenous germ cells should be transplanted into the recipients. For the transplantation procedure, donor testes from a transgenic Nile tilapia strain carrying the medaka β-actin/enhanced green fluorescent protein (EGFP) gene were subjected to enzymatic dissociation. These testicular cells were then stained with PKH26 and microinjected into the peritoneal cavity of the recipient fish. To confirm colonization of the donor-derived germ cells, the recipient gonads were examined by fluorescent and confocal microscopy. PKH26-labeled cells exhibiting typical spermatogonial morphology were incorporated into the recipient gonads and were not rejected within 22 days posttransplantation. Long-term survival of transgenic donor-derived germ cells was then verified in the gonads of 5-month-old recipients and in the milt and vitelogenic oocytes of 1-year-old recipients, by means of PCR using EGFP-specific primers. EGFP-positive milt from adult male recipients was used to fertilize non-transgenic oocytes and produced transgenic offspring expressing the donor-derived phenotype. These results imply that long-term survival, proliferation, and differentiation of the donor-derived spermatogonia into vitelogenic oocytes and functional spermatozoa are all possible. Upon further improvements in the transplantation efficiency, this intraperitoneal transplantation system could become a valuable tool in the conservation of genetic resources for cichlid species.

  4. Radiation-induced bystander signaling from somatic cells to germ cells in Caenorhabditis elegans.

    PubMed

    Guo, Xiaoying; Sun, Jie; Bian, Po; Chen, Lianyun; Zhan, Furu; Wang, Jun; Xu, An; Wang, Yugang; Hei, Tom K; Wu, Lijun

    2013-09-01

    Recently, radiation-induced bystander effects (RIBE) have been studied in mouse models in vivo, which clearly demonstrated bystander effects among somatic cells. However, there is currently no evidence for RIBE between somatic cells and germ cells in animal models in vivo. In the current study, the model animal Caenorhabditis elegans was used to investigate the bystander signaling from somatic cells to germ cells, as well as underlying mechanisms. C. elegans body size allows for precise microbeam irradiation and the abundant mutant strains for genetic dissection relative to currently adopted mouse models make it ideal for such analysis. Our results showed that irradiation of posterior pharynx bulbs and tails of C. elegans enhanced the level of germ cell apoptosis in bystander gonads. The irradiation of posterior pharynx bulbs also increased the level of DNA damage in bystander germ cells and genomic instability in the F1 progeny of irradiated worms, suggesting a potential carcinogenic risk in progeny even only somatic cells of parents are exposed to ionizing radiation (IR). It was also shown that DNA damage-induced germ cell death machinery and MAPK signaling pathways were both involved in the induction of germ cell apoptosis by microbeam induced bystander signaling, indicating a complex cooperation among multiple signaling pathways for bystander effects from somatic cells to germ cells.

  5. Meiotic germ cells antagonize mesonephric cell migration and testis cord formation in mouse gonads

    PubMed Central

    Yao, Humphrey H.-C.; DiNapoli, Leo; Capel, Blanche

    2014-01-01

    Summary The developmental fate of primordial germ cells in the mammalian gonad depends on their environment. In the XY gonad, Sry induces a cascade of molecular and cellular events leading to the organization of testis cords. Germ cells are sequestered inside testis cords by 12.5 dpc where they arrest in mitosis. If the testis pathway is not initiated, germ cells spontaneously enter meiosis by 13.5 dpc, and the gonad follows the ovarian fate. We have previously shown that some testis-specific events, such as mesonephric cell migration, can be experimentally induced into XX gonads prior to 12.5 dpc. However, after that time, XX gonads are resistant to the induction of cell migration. In current experiments, we provide evidence that this effect is dependent on XX germ cells rather than on XX somatic cells. We show that, although mesonephric cell migration cannot be induced into normal XX gonads at 14.5 dpc, it can be induced into XX gonads depleted of germ cells. We also show that when 14.5 dpc XX somatic cells are recombined with XY somatic cells, testis cord structures form normally; however, when XX germ cells are recombined with XY somatic cells, cord structures are disrupted. Sandwich culture experiments suggest that the inhibitory effect of XX germ cells is mediated through short-range interactions rather than through a long-range diffusible factor. The developmental stage at which XX germ cells show a disruptive effect on the male pathway is the stage at which meiosis is normally initiated, based on the immunodetection of meiotic markers. We suggest that at the stage when germ cells commit to meiosis, they reinforce ovarian fate by antagonizing the testis pathway. PMID:14561636

  6. Lifetime stress experience: transgenerational epigenetics and germ cell programming

    PubMed Central

    Bale, Tracy L.

    2014-01-01

    The transgenerational epigenetic programming involved in the passage of environmental exposures to stressful periods from one generation to the next has been examined in human populations, and mechanistically in animal models. Epidemiological studies suggest that gestational exposures to environmental factors including stress are strongly associated with an increased risk of neurodevelopmental disorders, including attention deficit-hyperactivity disorder, schizophrenia, and autism spectrum disorders. Both maternal and paternal life experiences with stress can be passed on to offspring directly during pregnancy or through epigenetic marks in the germ cell. Animal models of parental stress have examined relevant offspring phenotypes and transgenerational outcomes, and provided unique insight into the germ cell epigenetic changes associated with disruptions in neurodevelopment. Understanding germline susceptibility to exogenous signals during stress exposure and the identification of the types of epigenetic marks is critical for defining mechanisms underlying disease risk. PMID:25364281

  7. Management of Pediatric Malignant Germ Cell Tumors: ICMR Consensus Document.

    PubMed

    Agarwala, Sandeep; Mitra, Aparajita; Bansal, Deepak; Kapoor, Gauri; Vora, Tushar; Prasad, Maya; Chinnaswamy, Girish; Arora, Brijesh; Radhakrishnan, Venkatraman; Laskar, Siddharth; Kaur, Tanvir; Dhaliwal, Rupinder Singh; Rath, G K; Bakhshi, Sameer

    2017-06-01

    With the introduction of cisplatin, the outcome of children with malignant germ cell tumors (MGCT) has improved to nearly 90% 5 year survival. Over the years, through the results of various multinational co-operative trials, the chemotherapy and surgical guidelines for both the gonadal and extra-gonadal MGCTs have been refined to decrease the early and late morbidities and at the same time improve survival. Introduction of risk categorization has further added to this effort. There has been no recommendation on how the children with malignant germ cell tumors should be treated in India. The current manuscript is written with the objective of developing a consensus guideline for practitioners at a National level. Based on extensively reviewed literature and personal experience of the major pediatric oncology centres in India, the ICMR Expert group has made recommendations for management of children with MGCT India.

  8. Mediastinal germ cell tumors: a radiologic-pathologic review.

    PubMed

    Drevelegas, A; Palladas, P; Scordalaki, A

    2001-01-01

    Germ cell tumors of the mediastinum are histologically identical to those found in the testes and ovaries. Early diagnosis and treatment improve the survival rate. Imaging studies of teratoma demonstrate a rounded, often lobulated heterogeneous mass containing soft tissue elements with fluid and fat attenuation. Calcification is present in 20-43% of cases. Seminomas are large masses of homogeneous soft tissue attenuation. Malignant nonseminomatous germ cell tumors are heterogeneous tumors with irregular borders due to invasion of adjacent structures. CT shows the location and extent of the tumors as well as intrinsic elements including soft tissue, fat, fluid, and calcification. CT is the modality of choice for the diagnostic evaluation of these tumors. MRI reveals masses of heterogeneous signal intensity, is more sensitive in depicting infiltration of the adjacent structures by fat plane obliteration, and is performed as an ancillary study.

  9. Paraneoplastic tumefactive demyelination with underlying combined germ cell cancer.

    PubMed

    Broadfoot, Jack R; Archer, Hilary A; Coulthard, Elizabeth; Appelman, Auke P A; Sutak, Judit; Braybrooke, Jeremy P; Love, Seth

    2015-12-01

    Paraneoplastic demyelination is a rare disorder of the central nervous system. We describe a 60-year-old man with tumefactive demyelination who had an underlying retroperitoneal germ cell cancer. He presented with visuospatial problems and memory loss and had a visual field defect. His MRI was interpreted as a glioma but stereotactic biopsy showed active demyelination. Investigation for multiple sclerosis was negative but CT imaging showed retroperitoneal lymphadenopathy, and nodal biopsy confirmed a combined germ cell cancer. He responded poorly to corticosteroid treatment, and his visual field defect progressed. However, 6 months after plasma exchange and successful chemotherapy, he has partially improved clinically and radiographically. Tumefactive demyelination is typically associated with multiple sclerosis but may be paraneoplastic. It is important to recognise paraneoplastic tumefactive demyelination early, as the neurological outcome relies on treating the associated malignancy.

  10. Lifetime stress experience: transgenerational epigenetics and germ cell programming.

    PubMed

    Bale, Tracy L

    2014-09-01

    The transgenerational epigenetic programming involved in the passage of environmental exposures to stressful periods from one generation to the next has been examined in human populations, and mechanistically in animal models. Epidemiological studies suggest that gestational exposures to environmental factors including stress are strongly associated with an increased risk of neurodevelopmental disorders, including attention deficit-hyperactivity disorder, schizophrenia, and autism spectrum disorders. Both maternal and paternal life experiences with stress can be passed on to offspring directly during pregnancy or through epigenetic marks in the germ cell. Animal models of parental stress have examined relevant offspring phenotypes and transgenerational outcomes, and provided unique insight into the germ cell epigenetic changes associated with disruptions in neurodevelopment. Understanding germline susceptibility to exogenous signals during stress exposure and the identification of the types of epigenetic marks is critical for defining mechanisms underlying disease risk.

  11. The Diversity of Nanos Expression in Echinoderm Embryos Supports Different Mechanisms in Germ Cell Specification

    PubMed Central

    Fresques, Tara; Swartz, S. Zachary; Juliano, Celina; Morino, Yoshiaki; Kikuchi, Mani; Akasaka, Koji; Wada, Hiroshi; Yajima, Mamiko; Wessel, Gary M.

    2016-01-01

    Specification of the germ cell lineage is required for sexual reproduction in all animals. However, the timing and mechanisms of germ cell specification is remarkably diverse in animal development. Echinoderms, such as sea urchins and sea stars, are excellent model systems to study the molecular and cellular mechanisms that contribute to germ cell specification. In several echinoderm embryos tested, the germ cell factor Vasa accumulates broadly during early development and is restricted after gastrulation to cells that contribute to the germ cell lineage. In the sea urchin, however, the germ cell factor Vasa is restricted to a specific lineage by the 32-cell stage. We therefore hypothesized that the germ cell specification program in the sea urchin/Euechinoid lineage has evolved to an earlier developmental time point. To test this hypothesis we determined the expression pattern of a second germ cell factor, Nanos, in four out of five extant echinoderm clades. Here we find that Nanos mRNA does not accumulate until the blastula stage or later during the development of all other echinoderm embryos except those that belong to the Echinoid lineage. Instead, Nanos is expressed in a restricted domain at the 32–128 cell stage in Echinoid embryos. Our results support the model that the germ cell specification program underwent a heterochronic shift in the Echinoid lineage. A comparison of Echinoid and non-Echinoid germ cell specification mechanisms will contribute to our understanding of how these mechanisms have changed during animal evolution. PMID:27402572

  12. The diversity of nanos expression in echinoderm embryos supports different mechanisms in germ cell specification.

    PubMed

    Fresques, Tara; Swartz, Steven Zachary; Juliano, Celina; Morino, Yoshiaki; Kikuchi, Mani; Akasaka, Koji; Wada, Hiroshi; Yajima, Mamiko; Wessel, Gary M

    2016-07-01

    Specification of the germ cell lineage is required for sexual reproduction in all animals. However, the timing and mechanisms of germ cell specification is remarkably diverse in animal development. Echinoderms, such as sea urchins and sea stars, are excellent model systems to study the molecular and cellular mechanisms that contribute to germ cell specification. In several echinoderm embryos tested, the germ cell factor Vasa accumulates broadly during early development and is restricted after gastrulation to cells that contribute to the germ cell lineage. In the sea urchin, however, the germ cell factor Vasa is restricted to a specific lineage by the 32-cell stage. We therefore hypothesized that the germ cell specification program in the sea urchin/Euechinoid lineage has evolved to an earlier developmental time point. To test this hypothesis we determined the expression pattern of a second germ cell factor, Nanos, in four out of five extant echinoderm clades. Here we find that Nanos mRNA does not accumulate until the blastula stage or later during the development of all other echinoderm embryos except those that belong to the Echinoid lineage. Instead, Nanos is expressed in a restricted domain at the 32-128 cell stage in Echinoid embryos. Our results support the model that the germ cell specification program underwent a heterochronic shift in the Echinoid lineage. A comparison of Echinoid and non-Echinoid germ cell specification mechanisms will contribute to our understanding of how these mechanisms have changed during animal evolution. © 2016 Wiley Periodicals, Inc.

  13. Telomere homeostasis in mammalian germ cells: a review.

    PubMed

    Reig-Viader, Rita; Garcia-Caldés, Montserrat; Ruiz-Herrera, Aurora

    2016-06-01

    Telomeres protect against genome instability and participate in chromosomal movements during gametogenesis, especially in meiosis. Thus, maintaining telomere structure and telomeric length is essential to both cell integrity and the production of germ cells. As a result, alteration of telomere homeostasis in the germ line may result in the generation of aneuploid gametes or gametogenesis disruption, triggering fertility problems. In this work, we provide an overview on fundamental aspects of the literature regarding the organization of telomeres in mammalian germ cells, paying special attention to telomere structure and function, as well as the maintenance of telomeric length during gametogenesis. Moreover, we discuss the different roles recently described for telomerase and TERRA in maintaining telomere functionality. Finally, we review how new findings in the field of reproductive biology underscore the role of telomere homeostasis as a potential biomarker for infertility. Overall, we anticipate that the study of telomere stability and equilibrium will contribute to improve diagnoses of patients; assess the risk of infertility in the offspring; and in turn, find new treatments.

  14. Role of surgical resection for refractory germ cell tumors.

    PubMed

    Daneshmand, Siamak

    2015-08-01

    This article aims to critically review the current recommendations with regard to the role of surgery following salvage chemotherapy, growing teratoma syndrome, late relapse, as well as malignant transformation. All the literature published in English and available on Pubmed pertaining to refractory germ cell tumors was reviewed and the relevant articles, as well as our own institutional experience were included in this review. There is universal agreement that patients with non-seminoma who have residual tumor measuring greater than one centimeter should undergo post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) for resection of potential teratoma or viable germ cell tumor. The role of surgical resection is less clear in patients who are deemed to have germ cell tumors refractory to chemotherapy. Patients with residual masses following second line therapy, those with growing teratoma, late relapse, and malignant transformation should all be considered for upfront surgical resection. Compared with the typical PC-RPLND, these operations are generally more complex, with a higher proportion requiring adjunctive procedures; and should be performed in experienced, tertiary referral centers. Patients who have complete resection of disease are sill curable and patients with chemorefractory disease should have evaluation by an expert surgeon. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Prepubertal male rats with high rates of germ-cell apoptosis present exacerbated rates of germ-cell apoptosis after serotonin depletion.

    PubMed

    Méndez Palacios, Néstor; Escobar, María Elena Ayala; Mendoza, Maximino Méndez; Crispín, Rubén Huerta; Andrade, Octavio Guerrero; Melández, Javier Hernández; Martínez, Andrés Aragón

    2016-04-01

    Male germ-cell apoptosis occurs naturally and can be increased by exposure to drugs and toxic chemicals. Individuals may have different rates of apoptosis and are likely to also exhibit differential sensitivity to outside influences. Previously, we reported that p-chloroamphetamine (pCA), a substance that inhibits serotonin synthesis, induced germ-cell apoptosis in prepubertal male rats. Here, we identified prepubertal rats with naturally high or low rates of germ-cell apoptosis and evaluated gene expression in both groups. Bax and Shbg mRNA levels were higher in rats with high rates of germ-cell apoptosis. Rats were then treated with pCA and the neuro-hormonal response and gene expression were evaluated. Treatment with pCA induced a reduction in serotonin concentrations but levels of sex hormones and gonadotrophins were not changed. Rats with initially high rates of germ-cell apoptosis had even higher rates of germ-cell apoptosis after treatment with pCA. In rats with high rates of germ-cell apoptosis Bax mRNA expression remained high after treatment with pCA. On the basis of category, an inverse relationship between mRNA expression of Bax and Bcl2, Bax and AR and Bax and Hsd3b2 was found. Here we provide evidence that innate levels of germ-cell apoptosis could be explained by the level of mRNA expression of genes involved with apoptosis and spermatogenesis.

  16. Tre1, a G Protein-Coupled Receptor, Directs Transepithelial Migration of Drosophila Germ Cells

    PubMed Central

    Bainton, Roland J; Heberlein, Ulrike

    2003-01-01

    In most organisms, germ cells are formed distant from the somatic part of the gonad and thus have to migrate along and through a variety of tissues to reach the gonad. Transepithelial migration through the posterior midgut (PMG) is the first active step during Drosophila germ cell migration. Here we report the identification of a novel G protein-coupled receptor (GPCR), Tre1, that is essential for this migration step. Maternal tre1 RNA is localized to germ cells, and tre1 is required cell autonomously in germ cells. In tre1 mutant embryos, most germ cells do not exit the PMG. The few germ cells that do leave the midgut early migrate normally to the gonad, suggesting that this gene is specifically required for transepithelial migration and that mutant germ cells are still able to recognize other guidance cues. Additionally, inhibiting small Rho GTPases in germ cells affects transepithelial migration, suggesting that Tre1 signals through Rho1. We propose that Tre1 acts in a manner similar to chemokine receptors required during transepithelial migration of leukocytes, implying an evolutionarily conserved mechanism of transepithelial migration. Recently, the chemokine receptor CXCR4 was shown to direct migration in vertebrate germ cells. Thus, germ cells may more generally use GPCR signaling to navigate the embryo toward their target. PMID:14691551

  17. Melatonin receptor genes (mel-1a, mel-1b, mel-1c) are differentially expressed in the avian germ line.

    PubMed

    Kawashima, Takaharu; Stepińska, Urszula; Kuwana, Takashi; Olszańska, Bozenna

    2008-09-01

    The presence of melatonin receptor transcripts (mel-1a, mel-1b and mel-1c) was investigated in primordial germ cells (PGCs), immature and mature oocytes, and sperm of Japanese quail by reverse transcription--polymerase chain reaction (RT-PCR). The mel-1a transcript was detected in as few as in a thousand PGCs. Significant differences in the expression of melatonin receptor genes were found in differentiating germ cells: in PGCs only the mel-1a receptor was expressed, in blastoderms and immature oocytes all three transcripts (mel-1a, mel-1b, mel-1c) were present, while in mature ovulated oocytes the predominant transcript was mel-1c (with sporadic occurrence of mel-1a and mel-1b). In sperm, mel-1a and mel-1c were present but mel-1b was absent. This indicates that the expression of melatonin receptor genes changes throughout the differentiation of PGCs into adult gametes: during oocyte differentiation two additional transcripts, mel-1b and mel-1c, are synthesized in addition to mel-1a, but at oocyte maturation, mel-1a and mel-1b are degraded and only mel-1c remains. During male line (spermatozoa) differentiation mel-1c is transcribed in addition to mel-1a, with mel-1b being completely absent. Since melatonin and the activities of enzymes participating in melatonin synthesis are present in the avian yolk, it is reasonable to suggest a role for this molecule in early avian development and germ line differentiation. We propose that melatonin may act as a signaling molecule regulating some differentiation processes (e.g., cell proliferation, migration, etc.) before the formation of neural and hormonal systems.

  18. Presence of Germ Cells in Disorders of Sex Development: Implications for Fertility Potential and Preservation

    PubMed Central

    Finlayson, Courtney; Fritsch, Michael K.; Johnson, Emilie K.; Rosoklija, Ilina; Gosiengfiao, Yasmin; Yerkes, Elizabeth; Madonna, Mary Beth; Woodruff, Teresa K.; Cheng, Earl

    2017-01-01

    Purpose We sought to determine the presence of germ cells in the gonads of patients with disorders of sex development to establish whether preservation of germ cells for future fertility potential is possible. We hypothesized that germ cells are present but vary by age and diagnosis. Materials and Methods We reviewed histology from patients with disorders of sex development who underwent gonadectomy/biopsy from 2002 to 2014 at a single institution for pathological classification of the gonad, composition of gonadal stroma and germ cell presence. Results A total of 44 patients were identified and germ cells were present in 68%. The presence and average number of germ cells per mm2 were analyzed by gonad type and diagnosis. By gonad type all ovotestes, most testes, ovaries and dysgenetic testes, and 15% of streak gonads had germ cells present. By diagnosis germ cells were present in all patients with complete androgen insensitivity syndrome, Denys-Drash syndrome, SRY mutation, mixed gonadal dysgenesis, ovotesticular conditions and StAR (steroid acute regulatory protein) deficiency, in some patients with persistent müllerian duct syndrome, XO/XY Turner syndrome and disorders of sex development not otherwise specified, and in none with complete or partial gonadal dysgenesis. Germ cells were present in the gonads of 88% of patients 0 to 3 years old, 50% of those 4 to 11 years old and 43% of those older than 12 years. Conclusions Germ cells were present in the majority of our cohort and the presence decreased with age. This novel, fertility driven evaluation of germ cell quantity in a variety of disorders of sex development suggests that fertility potential may be greater than previously thought. Further studies must be done to evaluate a larger population and examine germ cell quality to determine the viability of these germ cells. PMID:27840018

  19. Presence of Germ Cells in Disorders of Sex Development: Implications for Fertility Potential and Preservation.

    PubMed

    Finlayson, Courtney; Fritsch, Michael K; Johnson, Emilie K; Rosoklija, Ilina; Gosiengfiao, Yasmin; Yerkes, Elizabeth; Madonna, Mary Beth; Woodruff, Teresa K; Cheng, Earl

    2017-03-01

    We sought to determine the presence of germ cells in the gonads of patients with disorders of sex development to establish whether preservation of germ cells for future fertility potential is possible. We hypothesized that germ cells are present but vary by age and diagnosis. We reviewed histology from patients with disorders of sex development who underwent gonadectomy/biopsy from 2002 to 2014 at a single institution for pathological classification of the gonad, composition of gonadal stroma and germ cell presence. A total of 44 patients were identified and germ cells were present in 68%. The presence and average number of germ cells per mm(2) were analyzed by gonad type and diagnosis. By gonad type all ovotestes, most testes, ovaries and dysgenetic testes, and 15% of streak gonads had germ cells present. By diagnosis germ cells were present in all patients with complete androgen insensitivity syndrome, Denys-Drash syndrome, SRY mutation, mixed gonadal dysgenesis, ovotesticular conditions and StAR (steroid acute regulatory protein) deficiency, in some patients with persistent müllerian duct syndrome, XO/XY Turner syndrome and disorders of sex development not otherwise specified, and in none with complete or partial gonadal dysgenesis. Germ cells were present in the gonads of 88% of patients 0 to 3 years old, 50% of those 4 to 11 years old and 43% of those older than 12 years. Germ cells were present in the majority of our cohort and the presence decreased with age. This novel, fertility driven evaluation of germ cell quantity in a variety of disorders of sex development suggests that fertility potential may be greater than previously thought. Further studies must be done to evaluate a larger population and examine germ cell quality to determine the viability of these germ cells. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  20. Engineering musculoskeletal tissues with human embryonic germ cell derivatives.

    PubMed

    Varghese, Shyni; Hwang, Nathaniel S; Ferran, Angela; Hillel, Alexander; Theprungsirikul, Parnduangjai; Canver, Adam C; Zhang, Zijun; Gearhart, John; Elisseeff, Jennifer

    2010-04-01

    The cells derived from differentiating embryoid bodies of human embryonic germ (hEG) cells express a broad spectrum of gene markers and have been induced toward ecto- and endodermal lineages. We describe here in vitro and in vivo differentiation of hEG-derived cells (LVEC line) toward mesenchymal tissues. The LVEC cells express many surface marker proteins characteristic of mesenchymal stem cells and differentiated into cartilage, bone, and fat. Homogenous hyaline cartilage was generated from cells after 63 population doublings. In vivo results demonstrate cell survival, differentiation, and tissue formation. The high proliferative capacity of hEG-derived cells and their ability to differentiate and form three-dimensional mesenchymal tissues without teratoma formation underscores their significant potential for regenerative medicine. The adopted coculture system also provides new insights into how a microenvironment comprised of extracellular and cellular components may be harnessed to generate hierarchically complex tissues from pluripotent cells.

  1. Generation of exogenous germ cells in the ovaries of sterile NANOS3-null beef cattle

    PubMed Central

    Ideta, Atsushi; Yamashita, Shiro; Seki-Soma, Marie; Yamaguchi, Ryosaku; Chiba, Shiori; Komaki, Haruna; Ito, Tetsuya; Konishi, Masato; Aoyagi, Yoshito; Sendai, Yutaka

    2016-01-01

    Blastocyst complementation (BC) systems have enabled in vivo generation of organs from allogeneic pluripotent cells, compensating for an empty germ cell niche in gene knockout (KO) animals. Here, we succeeded in producing chimeric beef cattle (Wagyu) by transferring allogenic germ cells into ovaries using somatic cell nuclear transfer and BC technology. The KO of NANOS3 (NANOS3−/−) in Wagyu bovine ovaries produced a complete loss of germ cells. Holstein blastomeres (NANOS3+/+) were injected into NANOS3−/− Wagyu embryos. Subsequently, exogenous germ cells (NANOS3+/+) were identified in the NANOS3−/− ovary. These results clearly indicate that allogeneic germ cells can be generated in recipient germ cell-free gonads using cloning and BC technologies. PMID:27117862

  2. Generation of exogenous germ cells in the ovaries of sterile NANOS3-null beef cattle.

    PubMed

    Ideta, Atsushi; Yamashita, Shiro; Seki-Soma, Marie; Yamaguchi, Ryosaku; Chiba, Shiori; Komaki, Haruna; Ito, Tetsuya; Konishi, Masato; Aoyagi, Yoshito; Sendai, Yutaka

    2016-04-27

    Blastocyst complementation (BC) systems have enabled in vivo generation of organs from allogeneic pluripotent cells, compensating for an empty germ cell niche in gene knockout (KO) animals. Here, we succeeded in producing chimeric beef cattle (Wagyu) by transferring allogenic germ cells into ovaries using somatic cell nuclear transfer and BC technology. The KO of NANOS3 (NANOS3(-/-)) in Wagyu bovine ovaries produced a complete loss of germ cells. Holstein blastomeres (NANOS3(+/+)) were injected into NANOS3(-/-) Wagyu embryos. Subsequently, exogenous germ cells (NANOS3(+/+)) were identified in the NANOS3(-/-) ovary. These results clearly indicate that allogeneic germ cells can be generated in recipient germ cell-free gonads using cloning and BC technologies.

  3. Successful Reconstruction of Tooth Germ with Cell Lines Requires Coordinated Gene Expressions from the Initiation Stage

    PubMed Central

    Komine, Akihiko; Tomooka, Yasuhiro

    2012-01-01

    Tooth morphogenesis is carried out by a series of reciprocal interactions between the epithelium and mesenchyme in embryonic germs. Previously clonal dental epithelial cell (epithelium of molar tooth germ (emtg)) lines were established from an embryonic germ. They were odontogenic when combined with a dental mesenchymal tissue, although the odontogenesis was quantitatively imperfect. To improve the microenvironment in the germs, freshly isolated dental epithelial cells were mixed with cells of lines, and germs were reconstructed in various combinations. The results demonstrated that successful tooth construction depends on the mixing ratio, the age of dental epithelial cells and the combination with cell lines. Analyses of gene expression in these germs suggest that some signal(s) from dental epithelial cells makes emtg cells competent to communicate with mesenchymal cells and the epithelial and mesenchymal compartments are able to progress odontogenesis from the initiation stage. PMID:24710535

  4. Autonomous regulation of sex-specific developmental programming in mouse fetal germ cells.

    PubMed

    Iwahashi, Kazuhiro; Yoshioka, Hirotaka; Low, Eleanor W; McCarrey, John R; Yanagimachi, Ryuzo; Yamazaki, Yukiko

    2007-10-01

    In mice, unique events regulating epigenetic programming (e.g., genomic imprinting) and replication state (mitosis versus meiosis) occur during fetal germ cell development. To determine whether these processes are autonomously programmed in fetal germ cells or are dependent upon ongoing instructive interactions with surrounding gonadal somatic cells, we isolated male and female germ cells at 13.5 days postcoitum (dpc) and maintained them in culture for 6 days, either alone or in the presence of feeder cells or gonadal somatic cells. We examined allele-specific DNA methylation in the imprinted H19 and Snrpn genes, and we also determined whether these cells remained mitotic or entered meiosis. Our results show that isolated male germ cells are able to establish a characteristic "paternal" methylation pattern at imprinted genes in the absence of any support from somatic cells. On the other hand, cultured female germ cells maintain a hypomethylated status at these loci, characteristic of the normal "maternal" methylation pattern in endogenous female germ cells before birth. Further, the surviving female germ cells entered first meiotic prophase and reached the pachytene stage, whereas male germ cells entered mitotic arrest. These results indicate that mechanisms controlling both epigenetic programming and replication state are autonomously regulated in fetal germ cells that have been exposed to the genital ridge prior to 13.5 dpc.

  5. Generation of germ cells in vitro in the era of induced pluripotent stem cells.

    PubMed

    Imamura, Masanori; Hikabe, Orie; Lin, Zachary Yu-Ching; Okano, Hideyuki

    2014-01-01

    Induced pluripotent stem cells (iPSCs) are stem cells that can be artificially generated via "cellular reprogramming" using gene transduction in somatic cells. iPSCs have enormous potential in stem-cell biology as they can give rise to numerous cell lineages, including the three germ layers. An evaluation of germ-line competency by blastocyst injection or tetraploid complementation, however, is critical for determining the developmental potential of mouse iPSCs towards germ cells. Recent studies have demonstrated that primordial germ cells obtained by the in vitro differentiation of iPSCs produce functional gametes as well as healthy offspring. These findings illustrate not only that iPSCs are developmentally similar to embryonic stem cells (ESCs), but also that somatic cells from adult tissues can produce gametes in vitro, that is, if they are reprogrammed into iPSCs. In this review, we discuss past and recent advances in the in vitro differentiation of germ cells using pluripotent stem cells, with an emphasis on ESCs and iPSCs. While this field of research is still at a stage of infancy, it holds great promises for investigating the mechanisms of germ-cell development, especially in humans, and for advancing reproductive and developmental engineering technologies in the future. © 2013 Wiley Periodicals, Inc.

  6. Human somatic cells subjected to genetic induction with six germ line-related factors display meiotic germ cell-like features

    PubMed Central

    Medrano, Jose V.; Martínez-Arroyo, Ana M.; Míguez, Jose M.; Moreno, Inmaculada; Martínez, Sebastián; Quiñonero, Alicia; Díaz-Gimeno, Patricia; Marqués-Marí, Ana I.; Pellicer, Antonio; Remohí, Jose; Simón, Carlos

    2016-01-01

    The in vitro derivation of human germ cells has attracted interest in the last years, but their direct conversion from human somatic cells has not yet been reported. Here we tested the ability of human male somatic cells to directly convert into a meiotic germ cell-like phenotype by inducing them with a combination of selected key germ cell developmental factors. We started with a pool of 12 candidates that were reduced to 6, demonstrating that ectopic expression of the germ line-related genes PRDM1, PRDM14, LIN28A, DAZL, VASA and SYCP3 induced direct conversion of somatic cells (hFSK (46, XY), and hMSC (46, XY)) into a germ cell-like phenotype in vitro. Induced germ cell-like cells showed a marked switch in their transcriptomic profile and expressed several post-meiotic germ line related markers, showed meiotic progression, evidence of epigenetic reprogramming, and approximately 1% were able to complete meiosis as demonstrated by their haploid status and the expression of several post-meiotic markers. Furthermore, xenotransplantation assays demonstrated that a subset of induced cells properly colonize the spermatogonial niche. Knowledge obtained from this work can be used to create in vitro models to study gamete-related diseases in humans. PMID:27112843

  7. LINEing germ and embryonic stem cells' silencing of retrotransposons.

    PubMed

    Ishiuchi, Takashi; Torres-Padilla, Maria-Elena

    2014-07-01

    Almost half of our genome is occupied by transposable elements. Although most of them are inactive, one type of non-long terminal repeat (LTR) retrotransposon, long interspersed nuclear element 1 (LINE1), is capable of retrotransposition. Two studies in this issue, Pezic and colleagues (pp. 1410-1428) and Castro-Diaz and colleagues (pp. 1397-1409), provide novel insight into the regulation of LINE1s in human embryonic stem cells and mouse germ cells and shed new light on the conservation of complex mechanisms to ensure silencing of transposable elements in mammals.

  8. Insights into female germ cell biology: from in vivo development to in vitro derivations

    PubMed Central

    Jung, Dajung; Kee, Kehkooi

    2015-01-01

    Understanding the mechanisms of human germ cell biology is important for developing infertility treatments. However, little is known about the mechanisms that regulate human gametogenesis due to the difficulties in collecting samples, especially germ cells during fetal development. In contrast to the mitotic arrest of spermatogonia stem cells in the fetal testis, female germ cells proceed into meiosis and began folliculogenesis in fetal ovaries. Regulations of these developmental events, including the initiation of meiosis and the endowment of primordial follicles, remain an enigma. Studying the molecular mechanisms of female germ cell biology in the human ovary has been mostly limited to spatiotemporal characterizations of genes or proteins. Recent efforts in utilizing in vitro differentiation system of stem cells to derive germ cells have allowed researchers to begin studying molecular mechanisms during human germ cell development. Meanwhile, the possibility of isolating female germline stem cells in adult ovaries also excites researchers and generates many debates. This review will mainly focus on presenting and discussing recent in vivo and in vitro studies on female germ cell biology in human. The topics will highlight the progress made in understanding the three main stages of germ cell developments: namely, primordial germ cell formation, meiotic initiation, and folliculogenesis. PMID:25652637

  9. Insights into female germ cell biology: from in vivo development to in vitro derivations.

    PubMed

    Jung, Dajung; Kee, Kehkooi

    2015-01-01

    Understanding the mechanisms of human germ cell biology is important for developing infertility treatments. However, little is known about the mechanisms that regulate human gametogenesis due to the difficulties in collecting samples, especially germ cells during fetal development. In contrast to the mitotic arrest of spermatogonia stem cells in the fetal testis, female germ cells proceed into meiosis and began folliculogenesis in fetal ovaries. Regulations of these developmental events, including the initiation of meiosis and the endowment of primordial follicles, remain an enigma. Studying the molecular mechanisms of female germ cell biology in the human ovary has been mostly limited to spatiotemporal characterizations of genes or proteins. Recent efforts in utilizing in vitro differentiation system of stem cells to derive germ cells have allowed researchers to begin studying molecular mechanisms during human germ cell development. Meanwhile, the possibility of isolating female germline stem cells in adult ovaries also excites researchers and generates many debates. This review will mainly focus on presenting and discussing recent in vivo and in vitro studies on female germ cell biology in human. The topics will highlight the progress made in understanding the three main stages of germ cell developments: namely, primordial germ cell formation, meiotic initiation, and folliculogenesis.

  10. Methods to study maternal regulation of germ cell specification in zebrafish

    PubMed Central

    Kaufman, O.H.; Marlow, F.L.

    2016-01-01

    The process by which the germ line is specified in the zebrafish embryo is under the control of maternal gene products that were produced during oogenesis. Zebrafish are highly amenable to microscopic observation of the processes governing maternal germ cell specification because early embryos are transparent, and the germ line is specified rapidly (within 4–5 h post fertilization). Advantages of zebrafish over other models used to study vertebrate germ cell formation include their genetic tractability, the large numbers of progeny, and the easily manipulable genome, all of which make zebrafish an ideal system for studying the genetic regulators and cellular basis of germ cell formation and maintenance. Classical molecular biology techniques, including expression analysis through in situ hybridization and forward genetic screens, have laid the foundation for our understanding of germ cell development in zebrafish. In this chapter, we discuss some of these classic techniques, as well as recent cutting-edge methodologies that have improved our ability to visualize the process of germ cell specification and differentiation, and the tracking of specific molecules involved in these processes. Additionally, we discuss traditional and novel technologies for manipulating the zebrafish genome to identify new components through loss-of-function studies of putative germ cell regulators. Together with the numerous aforementioned advantages of zebrafish as a genetic model for studying development, we believe these new techniques will continue to advance zebrafish to the forefront for investigation of the molecular regulators of germ cell specification and germ line biology. PMID:27312489

  11. The effects of steel mutation on testicular germ cell differentiation.

    PubMed

    Nishimune, Y; Haneji, T; Kitamura, Y

    1980-10-01

    The effects of artificial cryptorchidism and its surgical reversal on spermatogenesis were examined in germ cell mutant, S1/+ and wild type, +/+, mice. In cryptorchid testes no difference was found between S1/+ and +/+ mice in the number of undifferentiated type A spermatogonia. The activity of type A spermatogonia in mutant mice appeared normal as judged by its mitotic cell number and DNA synthesis. The surgical reversal of cryptorchidism resulted in regenerative differentiation of mature germ cells in both types of mice, but the pattern of cellular differentiation in the mutant testes was completely different from that of the wild type testes. At two steps of cellular differentiation, intermediate or type B spermatogonia and spermatid, the numbers of cells were much smaller in the S1/+ testes than those in the +/+ testes. The steel gene was therefore suggested to exert its effects on the differentiation of type A spermatogonia to intermediate or type B spermatogonia, on meiotic division and/or the survival rate of these cells, but not on the undifferentiated type A spermatogonia or stem cells.

  12. Germ Cells Are Not Required to Establish the Female Pathway in Mouse Fetal Gonads

    PubMed Central

    Maatouk, Danielle M.; Mork, Lindsey; Hinson, Ashley; Kobayashi, Akio; McMahon, Andrew P.; Capel, Blanche

    2012-01-01

    The fetal gonad is composed of a mixture of somatic cell lineages and germ cells. The fate of the gonad, male or female, is determined by a population of somatic cells that differentiate into Sertoli or granulosa cells and direct testis or ovary development. It is well established that germ cells are not required for the establishment or maintenance of Sertoli cells or testis cords in the male gonad. However, in the agametic ovary, follicles do not form suggesting that germ cells may influence granulosa cell development. Prior investigations of ovaries in which pre-meiotic germ cells were ablated during fetal life reported no histological changes during stages prior to birth. However, whether granulosa cells underwent normal molecular differentiation was not investigated. In cases where germ cell loss occurred secondary to other mutations, transdifferentiation of granulosa cells towards a Sertoli cell fate was observed, raising questions about whether germ cells play an active role in establishing or maintaining the fate of granulosa cells. We developed a group of molecular markers associated with ovarian development, and show here that the loss of pre-meiotic germ cells does not disrupt the somatic ovarian differentiation program during fetal life, or cause transdifferentiation as defined by expression of Sertoli markers. Since we do not find defects in the ovarian somatic program, the subsequent failure to form follicles at perinatal stages is likely attributable to the absence of germ cells rather than to defects in the somatic cells. PMID:23091613

  13. Chlorambucil effectively induces deletion mutations in mouse germ cells

    SciTech Connect

    Russell, L.B.; Hunsicker, P.R.; Cacheiro, N.L.A.; Bangham, J.W.; Russell, W.L.; Shelby, M.D. )

    1989-05-01

    The chemotherapeutic agent chlorambucil was found to be more effective than x-rays or any chemical investigated to data in inducing high yields of mouse germ-line mutations that appear to be deletions or other structural changes. Induction of mutations involving seven specific loci was studied after exposures of various male germ-cell stages to chlorambucil at 10-25 mg/kg. A total of 60,750 offspring was scored. Mutation rates in spermatogonial stem cells were not significantly increased over control values; this negative result is not attributable to selective elimination of mutant cells. Mutations were, however, clearly induced in treated post-stem-cell stages, among which marked variations in mutational response were found. Maximum yield occurred after exposure of early spermatids, with {approx} 1% of all offspring carrying a specific-locus mutation in the 10 mg/kg group. The stage-response pattern for chlorambucil differs from that of all other chemicals investigated to date in the specific-locus test. Thus far, all but one of the tested mutations induced by chlorambucil in post-stem-cell stages have been proved deletions or other structural changes by genetic, cytogenetic, and/or molecular criteria. Deletion mutations have recently been useful for molecular mapping and for structure-function correlations of genomic regions. For generating presumed large-lesion germline mutations at highest frequencies, chlorambucil may be the mutagen of choice.

  14. Autophagy is a cell survival program for female germ cells in the murine ovary.

    PubMed

    Gawriluk, Thomas R; Hale, Amber N; Flaws, Jodi A; Dillon, Christopher P; Green, Douglas R; Rucker, Edmund B

    2011-06-01

    It is estimated that infertility affects 15-20% of couples and can arise from female or male reproductive defects. Mouse models have ascribed roles to over 100 genes in the maintenance of female fertility. Although previous models have determined roles for apoptosis in male and female fertility, we find that compromised autophagy within the perinatal ovary, through the loss of Becn1 or Atg7, results in the premature loss of female germ cells. Becn1(+/-) ovaries have a 56% reduction of germ cells compared with control ovaries at post-natal day 1, whereas Atg7(-/-) ovaries lack discernable germ cells at this stage. Thus autophagy appears to be a cell survival mechanism to maintain the endowment of female germ cells prior to establishing primordial follicle pools in the ovary.

  15. A zebrafish homologue of the chemokine receptor Cxcr4 is a germ-cell guidance receptor.

    PubMed

    Knaut, Holger; Werz, Christian; Geisler, Robert; Nüsslein-Volhard, Christiane

    2003-01-16

    Germ cells preserve an individual's genetic information and transmit it to the next generation. Early in development germ cells are set aside and undergo a specialized developmental programme, a hallmark of which is the migration from their site of origin to the future gonad. In Drosophila, several factors have been identified that control germ-cell migration to their target tissues; however, the germ-cell chemoattractant or its receptor have remained unknown. Here we apply genetics and in vivo imaging to show that odysseus, a zebrafish homologue of the G-protein-coupled chemokine receptor Cxcr4, is required specifically in germ cells for their chemotaxis. odysseus mutant germ cells are able to activate the migratory programme, but fail to undergo directed migration towards their target tissue, resulting in randomly dispersed germ cells. SDF-1, the presumptive cognate ligand for Cxcr4, shows a similar loss-of-function phenotype and can recruit germ cells to ectopic sites in the embryo, thus identifying a vertebrate ligand-receptor pair guiding migratory germ cells at all stages of migration towards their target.

  16. A zebrafish homologue of the chemokine receptor Cxcr4 is a germ-cell guidance receptor

    NASA Astrophysics Data System (ADS)

    Knaut, Holger; Werz, Christian; Geisler, Robert; Tübingen 2000 Screen Consortium; Nüsslein-Volhard, Christiane

    2003-01-01

    Germ cells preserve an individual's genetic information and transmit it to the next generation. Early in development germ cells are set aside and undergo a specialized developmental programme, a hallmark of which is the migration from their site of origin to the future gonad. In Drosophila, several factors have been identified that control germ-cell migration to their target tissues; however, the germ-cell chemoattractant or its receptor have remained unknown. Here we apply genetics and in vivo imaging to show that odysseus, a zebrafish homologue of the G-protein-coupled chemokine receptor Cxcr4, is required specifically in germ cells for their chemotaxis. odysseus mutant germ cells are able to activate the migratory programme, but fail to undergo directed migration towards their target tissue, resulting in randomly dispersed germ cells. SDF-1, the presumptive cognate ligand for Cxcr4, shows a similar loss-of-function phenotype and can recruit germ cells to ectopic sites in the embryo, thus identifying a vertebrate ligand-receptor pair guiding migratory germ cells at all stages of migration towards their target.

  17. Intratubular germ cell neoplasia of the human testis: heterogeneous protein expression and relation to invasive potential.

    PubMed

    Mitchell, Rod T; E Camacho-Moll, Maria; Macdonald, Joni; Anderson, Richard A; Kelnar, Christopher J H; O'Donnell, Marie; Sharpe, Richard M; Smith, Lee B; Grigor, Ken M; Wallace, W Hamish B; Stoop, Hans; Wolffenbuttel, Katja P; Donat, Roland; Saunders, Philippa Tk; Looijenga, Leendert Hj

    2014-09-01

    Testicular germ cell cancer develops from premalignant intratubular germ cell neoplasia, unclassified cells that are believed to arise from failure of normal maturation of fetal germ cells from gonocytes (OCT4(+)/MAGEA4(-)) into pre-spermatogonia (OCT4(-)/MAGEA4(+)). Intratubular germ cell neoplasia cell subpopulations based on stage of germ cell differentiation have been described, however the importance of these subpopulations in terms of invasive potential has not been reported. We hypothesized that cells expressing an immature (OCT4(+)/MAGEA4(-)) germ cell profile would exhibit an increased proliferation rate compared with those with a mature profile (OCT4(+)/MAGEA4(+)). Therefore, we performed triple immunofluorescence and stereology to quantify the different intratubular germ cell neoplasia cell subpopulations, based on expression of germ cell (OCT4, PLAP, AP2γ, MAGEA4, VASA) and proliferation (Ki67) markers, in testis sections from patients with preinvasive disease, seminoma, and non-seminoma. We compared these subpopulations with normal human fetal testis and with seminoma cells. Heterogeneity of protein expression was demonstrated in intratubular germ cell neoplasia cells with respect to gonocyte and spermatogonial markers. It included an embryonic/fetal germ cell subpopulation lacking expression of the definitive intratubular germ cell neoplasia marker OCT4, that did not correspond to a physiological (fetal) germ cell subpopulation. OCT4(+)/MAGEA4(-) cells showed a significantly increased rate of proliferation compared with the OCT4(+)/MAGEA4(+) population (12.8 versus 3.4%, P<0.0001) irrespective of histological tumor type, reflected in the predominance of OCT4(+)/MAGEA4(-) cells in the invasive tumor component. Surprisingly, OCT4(+)/MAGEA4(-) cells in patients with preinvasive disease showed significantly higher proliferation compared to those with seminoma or non-seminoma (18.1 versus 10.2 versus 7.2%, P<0.05, respectively). In conclusion, this study

  18. The cell-free protein synthesis system from wheat germ.

    PubMed

    Takai, Kazuyuki; Endo, Yaeta

    2010-01-01

    The wheat-germ cell-free protein synthesis system had been one of the most efficient eukaryotic cell-free systems since it was first developed in 1964. However, radio-labeled amino acids had long been essential for detection of the products. Since the discovery of a method for prevention of the contamination by a protein synthesis inhibitor originated from endosperm, the wheat cell-free system has found a wide variety of applications in postgenomic high-throughput screening, structural biology, medicine, and so on. In this chapter, we describe a method for preparation of the cell-free extract and a standard protein synthesis method, as the methods for the applications are found in later chapters.

  19. Misexpression of cyclin D1 in embryonic germ cells promotes testicular teratoma initiation.

    PubMed

    Lanza, Denise G; Dawson, Emily P; Rao, Priya; Heaney, Jason D

    2016-01-01

    Testicular teratomas result from anomalies in embryonic germ cell development. In the 129 family of inbred mouse strains, teratomas arise during the same developmental period that male germ cells normally enter G1/G0 mitotic arrest and female germ cells initiate meiosis (the mitotic:meiotic switch). Dysregulation of this switch associates with teratoma susceptibility and involves three germ cell developmental abnormalities seemingly critical for tumor initiation: delayed G1/G0 mitotic arrest, retention of pluripotency, and misexpression of genes normally restricted to embryonic female and adult male germ cells. One misexpressed gene, cyclin D1 (Ccnd1), is a known regulator of cell cycle progression and an oncogene in many tissues. Here, we investigated whether Ccnd1 misexpression in embryonic germ cells is a determinant of teratoma susceptibility in mice. We found that CCND1 localizes to teratoma-susceptible germ cells that fail to enter G1/G0 arrest during the mitotic:meiotic switch and is the only D-type cyclin misexpressed during this critical developmental time frame. We discovered that Ccnd1 deficiency in teratoma-susceptible mice significantly reduced teratoma incidence and suppressed the germ cell proliferation and pluripotency abnormalities associated with tumor initiation. Importantly, Ccnd1 expression was dispensable for somatic cell development and male germ cell specification and maturation in tumor-susceptible mice, implying that the mechanisms by which Ccnd1 deficiency reduced teratoma incidence were germ cell autonomous and specific to tumorigenesis. We conclude that misexpression of Ccnd1 in male germ cells is a key component of a larger pro-proliferative program that disrupts the mitotic:meiotic switch and predisposes 129 inbred mice to testicular teratocarcinogenesis.

  20. Tests for urethane induction of germ-cell mutations and germ-cell killing in the mouse.

    PubMed

    Russell, L B; Hunsicker, P R; Oakberg, E F; Cummings, C C; Schmoyer, R L

    1987-08-01

    Urethane, a chemical that has given varied results in mutagenesis assays, was tested in the mouse specific-locus test, and its effect on germ-cell survival was explored. Altogether 32,828 offspring were observed from successive weekly matings of males exposed to the maximum tolerated i.p. dose of 1750 mg urethane/kg. The combined data rule out (at the 5% significance level) an induced mutation rate greater than 1.7 times the historical control rate. For spermatogonial stem cells alone, the multiple ruled out is 3.2, and for poststem-cell stages, 3.5. Litter sizes from successive conceptions made in any of the first 7 weeks give no indication of induced dominant lethality, confirming results of past dominant-lethal assays. That urethane (or an active metabolite) reaches germ cells is indicated by SCE induction in spermatogonia demonstrated by other investigators. Cytotoxic effects in spermatogonia are suggested by our finding of a slight reduction in numbers of certain types of spermatogonia in seminiferous tubule cross-sections and of a borderline decrease in the number of litters conceived during the 8th and 9th posttreatment weeks. The negative results for induction of gene mutations as well as clastogenic damage are at variance with Nomura's reports of dominant effects (F1 cancers and malformations) produced by urethane.

  1. Genome-wide methylation profiles in primary intracranial germ cell tumors indicate a primordial germ cell origin for germinomas.

    PubMed

    Fukushima, Shintaro; Yamashita, Satoshi; Kobayashi, Hisato; Takami, Hirokazu; Fukuoka, Kohei; Nakamura, Taishi; Yamasaki, Kai; Matsushita, Yuko; Nakamura, Hiromi; Totoki, Yasushi; Kato, Mamoru; Suzuki, Tomonari; Mishima, Kazuhiko; Yanagisawa, Takaaki; Mukasa, Akitake; Saito, Nobuhito; Kanamori, Masayuki; Kumabe, Toshihiro; Tominaga, Teiji; Nagane, Motoo; Iuchi, Toshihiko; Yoshimoto, Koji; Mizoguchi, Masahiro; Tamura, Kaoru; Sakai, Keiichi; Sugiyama, Kazuhiko; Nakada, Mitsutoshi; Yokogami, Kiyotaka; Takeshima, Hideo; Kanemura, Yonehiro; Matsuda, Masahide; Matsumura, Akira; Kurozumi, Kazuhiko; Ueki, Keisuke; Nonaka, Masahiro; Asai, Akio; Kawahara, Nobutaka; Hirose, Yuichi; Takayama, Tatusya; Nakazato, Yoichi; Narita, Yoshitaka; Shibata, Tatsuhiro; Matsutani, Masao; Ushijima, Toshikazu; Nishikawa, Ryo; Ichimura, Koichi

    2017-03-01

    Intracranial germ cell tumors (iGCTs) are the second most common brain tumors among children under 14 in Japan. The World Health Organization classification recognizes several subtypes of iGCTs, which are conventionally subclassified into pure germinoma or non-germinomatous GCTs. Recent exhaustive genomic studies showed that mutations of the genes involved in the MAPK and/or PI3K pathways are common in iGCTs; however, the mechanisms of how different subtypes develop, often as a mixed-GCT, are unknown. To elucidate the pathogenesis of iGCTs, we investigated 61 GCTs of various subtypes by genome-wide DNA methylation profiling. We showed that pure germinomas are characterized by global low DNA methylation, a unique epigenetic feature making them distinct from all other iGCTs subtypes. The patterns of methylation strongly resemble that of primordial germ cells (PGC) at the migration phase, possibly indicating the cell of origin for these tumors. Unlike PGC, however, hypomethylation extends to long interspersed nuclear element retrotransposons. Histologically and epigenetically distinct microdissected components of mixed-GCTs shared identical somatic mutations in the MAPK or PI3K pathways, indicating that they developed from a common ancestral cell.

  2. nanos function is essential for development and regeneration of planarian germ cells.

    PubMed

    Wang, Yuying; Zayas, Ricardo M; Guo, Tingxia; Newmark, Phillip A

    2007-04-03

    Germ cells are required for the successful propagation of sexually reproducing species. Understanding the mechanisms by which these cells are specified and how their totipotency is established and maintained has important biomedical and evolutionary implications. Freshwater planarians serve as fascinating models for studying these questions. They can regenerate germ cells from fragments of adult tissues that lack reproductive structures, suggesting that inductive signaling is involved in planarian germ cell specification. To study the development and regeneration of planarian germ cells, we have functionally characterized an ortholog of nanos, a gene required for germ cell development in diverse organisms, from Schmidtea mediterranea. In the hermaphroditic strain of this species, Smed-nanos mRNA is detected in developing, regenerating, and mature ovaries and testes. However, it is not detected in the vast majority of newly hatched planarians or in small tissue fragments that will ultimately regenerate germ cells, consistent with an epigenetic origin of germ cells. We show that Smed-nanos RNA interference (RNAi) results in failure to develop, regenerate, or maintain gonads in sexual planarians. Unexpectedly, Smed-nanos mRNA is also detected in presumptive testes primordia of asexual individuals that reproduce strictly by fission. These presumptive germ cells are lost after Smed-nanos RNAi, suggesting that asexual planarians specify germ cells, but their differentiation is blocked downstream of Smed-nanos function. Our results reveal a conserved function of nanos in germ cell development in planarians and suggest that these animals will serve as useful models for dissecting the molecular basis of epigenetic germ cell specification.

  3. Endogenous interleukin 18 regulates testicular germ cell apoptosis during endotoxemia.

    PubMed

    Inoue, Taketo; Aoyama-Ishikawa, Michiko; Kamoshida, Shingo; Nishino, Satoshi; Sasano, Maki; Oka, Nobuki; Yamashita, Hayato; Kai, Motoki; Nakao, Atsunori; Kotani, Joji; Usami, Makoto

    2015-08-01

    Orchitis (testicular swelling) often occurs during systemic inflammatory conditions, such as sepsis. Interleukin 18 (IL18) is a proinflammatory cytokine and is an apoptotic mediator during endotoxemia, but the role of IL18 in response to inflammation in the testes was unclear. WT and IL18 knockout (KO) mice were injected lipopolysaccharide (LPS) to induce endotoxemia and examined 12 and 48  h after LPS administration to model the acute and recovery phases of endotoxemia. Caspase activation was assessed using immunohistochemistry. Protein and mRNA expression were examined by western blot and quantitative real-time RT-PCR respectively. During the acute phase of endotoxemia, apoptosis (as indicated by caspase-3 cleavage) was increased in WT mice but not in IL18 KO mice. The death receptor-mediated and mitochondrial-mediated apoptotic pathways were both activated in the WT mice but not in the KO mice. During the recovery phase of endotoxemia, apoptosis was observed in the IL18 KO mice but not in the WT mice. Activation of the death-receptor mediated apoptotic pathway could be seen in the IL18 KO mice but not the WT mice. These results suggested that endogenous IL18 induces germ cell apoptosis via death receptor mediated- and mitochondrial-mediated pathways during the acute phase of endotoxemia and suppresses germ cell apoptosis via death-receptor mediated pathways during recovery from endotoxemia. Taken together, IL18 could be a new therapeutic target to prevent orchitis during endotoxemia.

  4. Management of poor-prognosis testicular germ cell tumors

    PubMed Central

    Khurana, Kiranpreet; Gilligan, Timothy D.; Stephenson, Andrew J.

    2010-01-01

    Currently, the outcome of patients with intermediate-and poor-risk germ cell tumors at diagnosis is optimized by the use of risk-appropriate chemotherapy and post-chemotherapy surgical resection of residual masses. Currently, there is no role for high-dose chemotherapy in the first-line setting. Patients who progress on first-line chemotherapy or who relapse after an initial complete response also have a poor prognosis. In the setting of early relapse, the standard approach at most centers is conventional-dose, ifosfamide-based regimens and post-chemotherapy resection of residual masses. The treatment of patients with late relapse is complete surgical resection whenever feasible. Salvage chemotherapy for late relapse may be used prior to surgery in patients where a complete resection is not feasible. A complete surgical resection of all residual sites of disease after chemotherapy is critical for the prevention of relapse and the long-term survival of patients with advanced germ cell tumors. PMID:20535296

  5. Control of mammalian germ cell entry into meiosis.

    PubMed

    Feng, Chun-Wei; Bowles, Josephine; Koopman, Peter

    2014-01-25

    Germ cells are unique in undergoing meiosis to generate oocytes and sperm. In mammals, meiosis onset is before birth in females, or at puberty in males, and recent studies have uncovered several regulatory steps involved in initiating meiosis in each sex. Evidence suggests that retinoic acid (RA) induces expression of the critical pre-meiosis gene Stra8 in germ cells of the fetal ovary, pubertal testis and adult testis. In the fetal testis, CYP26B1 degrades RA, while FGF9 further antagonises RA signalling to suppress meiosis. Failsafe mechanisms involving Nanos2 may further suppress meiosis in the fetal testis. Here, we draw together the growing knowledge relating to these meiotic control mechanisms, and present evidence that they are co-ordinately regulated and that additional factors remain to be identified. Understanding this regulatory network will illuminate not only how the foundations of mammalian reproduction are laid, but also how mis-regulation of these steps can result in infertility or germline tumours.

  6. Current chemotherapeutic approaches for recurrent or refractory germ cell tumors.

    PubMed

    O'Carrigan, Brent; Grimison, Peter

    2015-08-01

    Up to 25% of patients with metastatic testicular germ cell tumour (GCT) are not cured by first line therapy and require treatment for refractory or relapsed disease. A literature search was conducted through PubMed, Medline, Cochrane and EMBASE from January 1950 to April 2014 for articles relating to trials of chemotherapy for patients with relapsed or refractory germ cell tumours. Relevant review papers and conference proceedings were hand searched for additional references. A range of conventional dose chemotherapy (CDCT) regimens can provide durable remissions in 20-30% of patients at first or subsequent salvage. This article reviews the evidence underlying commonly used salvage CDCT based on ifosfamide and cisplatin such as TIP, VIP and VeIP; other active combinations; and single agent salvage regimens. The treatment of growing teratoma syndrome and malignant transformation of teratoma will also be discussed. Companion articles will explore the role of high dose chemotherapy (HDCT) and novel targeted agents. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  7. Modeling cell elongation during germ band retraction: cell autonomy versus applied anisotropic stress

    PubMed Central

    Lynch, Holley E.; Veldhuis, Jim; Brodland, G. Wayne; Hutson, M. Shane

    2014-01-01

    The morphogenetic process of germ band retraction in Drosophila embryos involves coordinated movements of two epithelial tissues – germ band and amnioserosa. The germ band shortens along its rostral-caudal or head-to-tail axis, widens along its perpendicular dorsal-ventral axis, and uncurls from an initial ‘U’ shape. The amnioserosa mechanically assists this process by pulling on the crook of the U-shaped germ band. The amnioserosa may also provide biochemical signals that drive germ band cells to change shape in a mechanically autonomous fashion. Here, we use a finite-element model to investigate how these two contributions reshape the germ band. We do so by modeling the response to laser-induced wounds in each of the germ band’s spatially distinct segments (T1-T3, A1-A9) during the middle of retraction when segments T1-A3 form the ventral arm of the ‘U’, A4-A7 form its crook, and A8-A9 complete the dorsal arm. We explore these responses under a range of externally applied stresses and internal anisotropy of cell edge tensions – akin to a planar cell polarity that can drive elongation of cells in a direction parallel to the minimum edge tension – and identify regions of parameter space (edge-tension anisotropy versus stress anisotropy) that best match previous experiments for each germ band segment. All but three germ band segments are best fit when the applied stress anisotropy and the edge-tension anisotropy work against one another – i.e., when the isolated effects would elongate cells in perpendicular directions. Segments in the crook of the germ band (A4-A7) have cells that elongate in the direction of maximum external stress, i.e., external stress anisotropy is dominant. In most other segments, the dominant factor is internal edge-tension anisotropy. These results are consistent with models in which the amnioserosa pulls on the crook of the germ band to mechanically assist retraction. In addition, they suggest a mechanical cue for edge

  8. Possibilities in Germ Cell Research: An Engineering Insight.

    PubMed

    Esfandiari, Fereshteh; Mashinchian, Omid; Ashtiani, Mohammad Kazemi; Ghanian, Mohammad Hossein; Hayashi, Katsuhiko; Saei, Amir Ata; Mahmoudi, Morteza; Baharvand, Hossein

    2015-12-01

    Germ cells (GCs) are responsible for fertility and disruptions in their development or function cause infertility. However, current knowledge about the diverse mechanisms involved in GC development and function is still in its infancy. This is mainly because there are low numbers of GCs, especially during embryonic development. A deeper understanding of GCs would enhance our ability to produce them from stem cells. In addition, such information would enable the production of healthy gametes for infertile couples. In this regard, pluripotent stem cells (PSCs) demonstrated a promising ability to produce GCs in vitro. In this review, we highlight recent advances in the field of tissue engineering that suggest novel strategies to enhance GC research.

  9. Germline stem cells are critical for sexual fate decision of germ cells

    PubMed Central

    2016-01-01

    Egg or sperm? The mechanism of sexual fate decision in germ cells has been a long‐standing issue in biology. A recent analysis identified foxl3 as a gene that determines the sexual fate decision of germ cells in the teleost fish, medaka. foxl3/Foxl3 acts in female germline stem cells to repress commitment into male fate (spermatogenesis), indicating that the presence of mitotic germ cells in the female is critical for continuous sexual fate decision of germ cells in medaka gonads. Interestingly, foxl3 is found in most vertebrate genomes except for mammals. This provides the interesting possibility that the sexual fate of germ cells in mammals is determined in a different way compared to foxl3‐possessing vertebrates. Considering the fact that germline stem cells are the cells where foxl3 begins to express and sexual fate decision initiates and mammalian ovary does not have typical germline stem cells, the mechanism in mammals may have been co‐evolved with germline stem cell loss in mammalian ovary. PMID:27699806

  10. Human iPS Cell-Derived Germ Cells: Current Status and Clinical Potential

    PubMed Central

    Ishii, Tetsuya

    2014-01-01

    Recently, fertile spermatozoa and oocytes were generated from mouse induced pluripotent (iPS) cells using a combined in vitro and in vivo induction system. With regard to germ cell induction from human iPS cells, progress has been made particularly in the male germline, demonstrating in vitro generation of haploid, round spermatids. Although iPS-derived germ cells are expected to be developed to yield a form of assisted reproductive technology (ART) that can address unmet reproductive needs, genetic and/or epigenetic instabilities abound in iPS cell generation and germ cell induction. In addition, there is still room to improve the induction protocol in the female germline. However, rapid advances in stem cell research are likely to make such obstacles surmountable, potentially translating induced germ cells into the clinical setting in the immediate future. This review examines the current status of the induction of germ cells from human iPS cells and discusses the clinical potential, as well as future directions. PMID:26237592

  11. Systemic mastocytosis in a patient with ovarian germ cell carcinoma and mast cell leukemia

    SciTech Connect

    Sun, G.; Hajianpour, M.J.; Hajianpour, A.K.

    1994-09-01

    We report a 12-year-old female with a history of mixed germ cell carcinoma of the right ovary who developed a generalized skin rash after oophorectomy and chemotherapy. She also presented with periodic episodes of flushing, anemia, tachycardia, shortness of breath, high fever, hepatosplenomegaly, nausea, abdominal cramping with diarrhea, and a papuloerythematous skin rash. There was no evidence of secondary carcinoma. Skin biopsy revealed nonspecific inflammatory cells with negative staining for mast cells. Peripheral blood smear showed an increased number of mast cells, thrombocytopenia and normal white cells count. Bone marrow showed hypercellularity with 38% of the nucleated cells being mast cells. Bone marrow chromosome analysis revealed hyperdiploidy in 30% of the cells: 58-64,XX, +1, +2, +5, +6, +7, +8, +14, +16, +18, +19, +19, +20, +21, +22. She expired two months after the occurrence of systemic mastocytosis. Systemic mastocytosis has been reported in association with hematopoietic disorders and with germ cell tumors. The association between mediastinal germ cell tumors and hematological malignancies has also been observed. To our knowledge, combination of most cell leukemia, systemic mastocytosis, and ovarian germ cell carcinoma has not been observed. It is know that mutations at the locus of either proto-oncogene c-kit receptor or its ligand, mast/stem cell factor (SCF) may impair the development of three stem cell populations: hematopoietic stem cells, germ cells and melanoblasts. There have been also extensive investigations on the expression and modulation of the SCF/c-kit interaction in various malignancies. Further molecular studies in patients with germ cell tumor/hematopoietic malignancy syndrome are required to delineate underlying mechanisms.

  12. Regulatory mechanism of protein metabolic pathway during the differentiation process of chicken male germ cell.

    PubMed

    Li, Dong; Zuo, Qisheng; Lian, Chao; Zhang, Lei; Shi, Qingqing; Zhang, Zhentao; Wang, Yingjie; Ahmed, Mahmoud F; Tang, Beibei; Xiao, Tianrong; Zhang, Yani; Li, Bichun

    2015-08-01

    We explored the regulatory mechanism of protein metabolism during the differentiation process of chicken male germ cells and provide a basis for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro. We sequenced the transcriptome of embryonic stem cells, primordial germ cells, and spermatogonial stem cells with RNA sequencing (RNA-Seq), bioinformatics analysis methods, and detection of the key genes by quantitative reverse transcription PCR (qRT-PCR). Finally, we found 16 amino acid metabolic pathways enriched in the biological metabolism during the differentiation process of embryonic stem cells to primordial germ cells and 15 amino acid metabolic pathways enriched in the differentiation stage of primordial germ cells to spermatogonial stem cells. We found three pathways, arginine-proline metabolic pathway, tyrosine metabolic pathway, and tryptophan metabolic pathway, significantly enriched in the whole differentiation process of embryonic stem cells to spermatogonial stem cells. Moreover, for these three pathways, we screened key genes such as NOS2, ADC, FAH, and IDO. qRT-PCR results showed that the expression trend of these genes were the same to RNA-Seq. Our findings showed that the three pathways and these key genes play an important role in the differentiation process of embryonic stem cells to male germ cells. These results provide basic information for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro.

  13. Human amniotic epithelial cells differentiate into cells expressing germ cell specific markers when cultured in medium containing serum substitute supplement

    PubMed Central

    2012-01-01

    Background Human amniotic epithelial cells (hAECs) maintain the plasticity of pregastrulation embryonic cells, having the potential to differentiate into all three germ layers. The potential of these cells to differentiate into cells expressing germ cell specific markers has never been described before. Methods In the present study, hAECs were cultured in medium containing serum substitute supplement (SSS). Gene and protein expression of germ cell and oocyte specific markers was assessed by reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence staining and flow activated cell sorter analysis (FACS) in hAECs at different time points during the differentiation into cells expressing germ cell specific markers. Results When cultured with SSS, already at passage 1, hAECs start to express the germ cell specific genes C-KIT, DAZL, VASA and ZP3 and at passage 5 large round cells, resembling oocytes, appeared. The cells express the germ cell specific marker DAZL, the oocyte specific markers GDF9 and ZP3 and the meiosis specific markers DMC1 and SCP3 at the protein level. Conclusions From our preliminary results we can conclude that hAECs have the potential to differentiate into cells expressing germ cell specific markers. PMID:23241213

  14. Primordial germ cell proliferation is impaired in Fused Toes mutant embryos.

    PubMed

    Kim, Bongki; Kim, Youngha; Sakuma, Rui; Hui, Chi-Chung; Rüther, Ulrich; Jorgensen, Joan S

    2011-01-15

    Over the first 4 days of their life, primordial germ cells invade the endoderm, migrate into and through the developing hindgut, and traverse to the genital ridge where they cluster and ultimately inhabit the nascent gonad. Specific signal-receptor combinations between primordial germ cells and their immediate environment establish successful migration and colonization. Here we demonstrate that disruption of a cluster of six genes on murine chromosome 8, as exemplified by the Fused Toes (Ft) mutant mouse model, results in severely decreased numbers of primordial germ cells within the early gonad. Primordial germ cell migration appeared normal within Ft mutant embryos; however, germ cell counts progressively decreased during this time. Although no difference in apoptosis was detected, we report a critical decrease in primordial germ cell proliferation by E12.5. The six genes within the Ft locus include the IrxB cluster (Irx3, -5, -6), Fts, Ftm, and Fto, of which only Ftm, Fto, and Fts are expressed in primordial germ cells of the early gonad. From these studies, we have discovered that the Ft locus on mouse chromosome 8 is associated with cell cycle deficits within the primordial germ cell population that initiates just before translocation into the genital ridge. Copyright © 2010 Elsevier Inc. All rights reserved.

  15. The role of sex chromosomes in mammalian germ cell differentiation: can the germ cells carrying X and Y chromosomes differentiate into fertile oocytes?

    PubMed

    Taketo, Teruko

    2015-01-01

    The sexual differentiation of germ cells into spermatozoa or oocytes is strictly regulated by their gonadal environment, testis or ovary, which is determined by the presence or absence of the Y chromosome, respectively. Hence, in normal mammalian development, male germ cells differentiate in the presence of X and Y chromosomes, and female germ cells do so in the presence of two X chromosomes. However, gonadal sex reversal occurs in humans as well as in other mammalian species, and the resultant XX males and XY females can lead healthy lives, except for a complete or partial loss of fertility. Germ cells carrying an abnormal set of sex chromosomes are efficiently eliminated by multilayered surveillance mechanisms in the testis, and also, though more variably, in the ovary. Studying the molecular basis for sex-specific responses to a set of sex chromosomes during gametogenesis will promote our understanding of meiotic processes contributing to the evolution of sex determining mechanisms. This review discusses the fate of germ cells carrying various sex chromosomal compositions in mouse models, the limitation of which may be overcome by recent successes in the differentiation of functional germ cells from embryonic stem cells under experimental conditions.

  16. Exploring embryonic germ line development in the water flea, Daphnia magna, by zinc-finger-containing VASA as a marker.

    PubMed

    Sagawa, Kazunori; Yamagata, Hideo; Shiga, Yasuhiro

    2005-06-01

    VASA is an ATP-dependent RNA helicase belonging to the DEAD-box family that, in many organisms, is specifically expressed in germ line cells throughout the life cycle, making it a powerful molecular marker to study germ line development. To obtain further information on germ line development in crustaceans, we cloned VASA cDNAs from three branchiopod species: water fleas Daphnia magna and Moina macrocopa, and brine shrimp Artemia franciscana. RNA helicase domains in branchiopod VASA were highly conserved among arthropod classes. However, N-terminal RNA-binding domains in branchiopod VASA were highly diverged and, unlike other arthropod VASA reported so far, possessed repeats of retroviral-type zinc finger (CCHC) motifs. Raising specific antibodies against Daphnia VASA revealed that the primordial germ cells (PGCs) in this organism segregate at a very early cleavage stage of embryogenesis in parthenogenetic and sexual eggs. Clusters of PGCs then start to migrate inside the embryo and finally settle at both sides of the intestine, the site of future gonad development. RNA analyses suggested that maternally supplied vasa mRNA was responsible for early VASA expression, while zygotic expression started during blastodermal stage of development.

  17. Paediatric germ cell tumours and congenital abnormalities: a Children's Oncology Group study

    PubMed Central

    Johnson, K J; Ross, J A; Poynter, J N; Linabery, A M; Robison, L L; Shu, X O

    2009-01-01

    Methods: Maternally reported congenital abnormalities (CAs) were examined in a case–control study of 278 cases of paediatric germ cell tumours (GCTs) and 423 controls. Results and conclusions Germ cell tumours were significantly associated with cryptorchidism in males (OR=10.8, 95% CI: 2.1–55.1), but not with any other specific CA in either sex. PMID:19603020

  18. Are There Human Germ-Cell Mutagens? We May Know Soon

    EPA Science Inventory

    The existence of agents that can induce germ-cell mutations in experimental systems has been recognized since 1927 with the discovery of the ability of X-rays to induce such mutations in Drosophila. Since then, various rodent-based assays have been used to identify ~50 germ-cell...

  19. Transient regression of an intracranial germ cell tumour after intravenous steroid administration: a case report

    PubMed Central

    Mascalchi, M.; Roncaroli, F.; Salvi, F.; Frank, G.

    1998-01-01

    Magnetic resonance imaging showed transient regression of the lesion after intravenous steroid administration in a patient with intracranial multifocal germ cell tumour. Prominent lymphocyte infiltration of the tumour was seen at histological examination and presumably accounts for the regression. Germ cell tumour must be included in the differential diagnosis of intracranial mass lesions sensitive to steroids.

 PMID:9598688

  20. Are There Human Germ-Cell Mutagens? We May Know Soon

    EPA Science Inventory

    The existence of agents that can induce germ-cell mutations in experimental systems has been recognized since 1927 with the discovery of the ability of X-rays to induce such mutations in Drosophila. Since then, various rodent-based assays have been used to identify ~50 germ-cell...

  1. Mixed Malignant Germ Cell Tumour of Third Ventricle with Hydrocephalus: A Rare Case with Recurrence

    PubMed Central

    Monappa, Vidya; Rao, Lakshmi; Kudva, Ranjini

    2014-01-01

    Malignant Germ Cell Tumours (GCTs) are rare, accounting for 3% of intracranial tumours and just like their extracranial counterparts represent a wide array of disease. Combination of Germinoma with Teratoma is very rare. Here in, we describe a case of Mixed Malignant Germ cell tumor of third ventricle with recurrence with emphasis on histopathological and radiological findings. PMID:25584231

  2. Specific variants of general transcription factors regulate germ cell development in diverse organisms

    PubMed Central

    Freiman, Richard N.

    2009-01-01

    Through the reductive divisions of meiosis, sexually reproducing organisms have gained the ability to produce specialized haploid cells called germ cells that fuse to establish the diploid genome of the resulting progeny. The totipotent nature of these germ cells is highlighted by their ability to provide a single fertilized egg cell with all the genetic information necessary to develop the complete repertoire of cell types of the future organism. Thus, the production of these germ cells must be tightly regulated to ensure the continued success of the germ line in future generations. One surprising germ cell development mechanism utilizes variation of the global transcriptional machinery, such as TFIID and TFIIA. Like histone variation, general transcription factor variation serves to produce gonadal-restricted or -enriched expression of selective transcriptional regulatory factors required for establishing and/or maintaining the germ line of diverse organisms. This strategy is observed among invertebrates and vertebrates, and perhaps plants, suggesting that a common theme in germ cell evolution is the diversification of selective promoter initiation factors to regulate critical gonadal-specific programs of gene expression required for sexual reproduction. This review discusses the identification and characterization of a subset of these specialized general transcription factors in diverse organisms that share a common goal of germ line regulation through transcriptional control at its most fundamental level. PMID:19437618

  3. An Overview on Predictive Biomarkers of Testicular Germ Cell Tumors.

    PubMed

    Chieffi, Paolo

    2017-02-01

    Testicular germ cell tumors (TGCTs) are frequent solid malignant tumors and cause of death in men between 20-40 years of age. Genetic and environmental factors play an important role in the origin and development of TGCTs. Although the majority of TGCTs are responsive to chemotherapy, about 20% of patient presents incomplete response or tumors relapse. In addition, the current treatments cause acute toxicity and several chronic collateral effects, including sterility. The present mini-review collectively summarize the most recent findings on the new discovered molecular biomarkers such as tyrosine kinases, HMGAs, Aurora B kinase, and GPR30 receptor predictive of TGCTs and as emerging new possible molecular targets for therapeutic strategies. J. Cell. Physiol. 232: 276-280, 2017. © 2016 Wiley Periodicals, Inc.

  4. Human germ cell formation in xenotransplants of induced pluripotent stem cells carrying X chromosome aneuploidies

    PubMed Central

    Dominguez, Antonia A.; Chiang, H. Rosaria; Sukhwani, Meena; Orwig, Kyle E.; Reijo Pera, Renee A.

    2014-01-01

    Turner syndrome is caused by complete or partial loss of the second sex chromosome and is characterized by spontaneous fetal loss in >90% of conceptions. Survivors possess an array of somatic and germline clinical characteristics. Induced pluripotent stem cells (iPSCs) offer an opportunity for insight into genetic requirements of the X chromosome linked to Turner syndrome. We derived iPSCs from Turner syndrome and control individuals and examined germ cell development as a function of X chromosome composition. We demonstrate that two X chromosomes are not necessary for reprogramming or maintenance of pluripotency and that there are minimal differences in gene expression, at the single cell level, linked to X chromosome aneuploidies. Formation of germ cells, as assessed in vivo through a murine xenotransplantation model, indicated that undifferentiated iPSCs, independent of X chromosome composition, are capable of forming germ-cell-like cells (GCLCs) in vivo. In combination with clinical data regarding infertility in women with X chromosome aneuploidies, results suggest that two intact X chromosomes are not required for human germ cell formation, qualitatively or quantitatively, but rather are likely to be required for maintenance of human germ cells to adulthood. PMID:25242416

  5. Human germ cell formation in xenotransplants of induced pluripotent stem cells carrying X chromosome aneuploidies.

    PubMed

    Dominguez, Antonia A; Chiang, H Rosaria; Sukhwani, Meena; Orwig, Kyle E; Reijo Pera, Renee A

    2014-09-22

    Turner syndrome is caused by complete or partial loss of the second sex chromosome and is characterized by spontaneous fetal loss in >90% of conceptions. Survivors possess an array of somatic and germline clinical characteristics. Induced pluripotent stem cells (iPSCs) offer an opportunity for insight into genetic requirements of the X chromosome linked to Turner syndrome. We derived iPSCs from Turner syndrome and control individuals and examined germ cell development as a function of X chromosome composition. We demonstrate that two X chromosomes are not necessary for reprogramming or maintenance of pluripotency and that there are minimal differences in gene expression, at the single cell level, linked to X chromosome aneuploidies. Formation of germ cells, as assessed in vivo through a murine xenotransplantation model, indicated that undifferentiated iPSCs, independent of X chromosome composition, are capable of forming germ-cell-like cells (GCLCs) in vivo. In combination with clinical data regarding infertility in women with X chromosome aneuploidies, results suggest that two intact X chromosomes are not required for human germ cell formation, qualitatively or quantitatively, but rather are likely to be required for maintenance of human germ cells to adulthood.

  6. Complete androgen insensitivity syndrome: factors influencing gonadal histology including germ cell pathology.

    PubMed

    Kaprova-Pleskacova, Jana; Stoop, Hans; Brüggenwirth, Hennie; Cools, Martine; Wolffenbuttel, Katja P; Drop, Stenvert L S; Snajderova, Marta; Lebl, Jan; Oosterhuis, J Wolter; Looijenga, Leendert H J

    2014-05-01

    Patients with complete androgen insensitivity syndrome are at an increased risk for the development of gonadal germ cell cancer. Residual androgen receptor (AR) activity and abnormal gonadal location may influence the survival of atypical germ cells and the development of other histopathological features. To assess this, we evaluated 37 gonads from 19 patients with complete androgen insensitivity (ranging in age from 3 months to 18 years). Histological abnormalities were examined using hematoxylin and eosin-stained sections and sections stained for POU5F1 and KITLG, markers of early changes in germ cells at risk for malignant transformation. Hamartomatous nodules (HNs), Leydig cell hyperplasia (LCH), decreased germ cells, tubular atrophy and stromal fibrosis were more pronounced as age increased (P<0.001). Expected residual AR activity acted as a positive predictor only for non-malignant germ cell survival in (post)pubertal patients (P<0.05). Immunohistochemical studies indicated that delayed maturation of germ cells was present in three patients, whereas intermediate changes that occurred between delayed maturation and intratubular germ cell neoplasia, designated pre-intratubular germ cell neoplasia, were identified in four cases. Intratubular germ cell neoplasia was observed in one patient. Neither POU5F1 nor KITLG expression was dependent on expected residual AR activity. An independent effect of inguinal versus abdominal position of the gonads was difficult to assess because inguinal gonads were present primarily in the youngest individuals. In conclusion, many histological changes occur increasingly with age. Expected residual AR activity contributes to better survival of the general germ cell population in (post)pubertal age; however, it did not seem to have an important role in the survival of the germ cells at risk for malignant transformation (defined by POU5F1 positivity and KITLG overexpression) in complete androgen insensitivity. Comparison of the high

  7. AZFa protein DDX3Y is differentially expressed in human male germ cells during development and in testicular tumours: new evidence for phenotypic plasticity of germ cells.

    PubMed

    Gueler, B; Sonne, S B; Zimmer, J; Hilscher, B; Hilscher, W; Græm, N; Rajpert-De Meyts, E; Vogt, P H

    2012-06-01

    DDX3Y (DBY), located within AZoospermia Factor a (AZFa) region of the human Y chromosome (Yq11), encodes a conserved DEAD-box RNA helicase expressed only in germ cells and with a putative function at G1-S phase of the cell cycle. Deletion of AZFa results most often in germ cell aplasia, i.e. Sertoli-cell-only syndrome. To investigate the function of DDX3Y during human spermatogenesis, we examined its expression during development and maturation of the testis and in several types of testicular germ cell tumours (TGCTs), including the pre-invasive carcinoma in situ (CIS) precursor cells which are believed to originate from fetal gonocytes. DDX3Y protein expression was analysed during development in different tissues by western blotting. The localization of DDX3Y in normal fetal and prepubertal testis tissue of different ages as well as in a series of distinct TGCT tissue samples (CIS, classical seminoma, spermatocytic seminoma, teratoma and embryonal carcinoma) was performed by immunohistochemistry. Germ cell-specific expression of DDX3Y protein was revealed in fetal prospermatogonia but not in gonocytes and not before the 17th gestational week. After birth, DDX3Y was expressed at first only in the nuclei of Ap spermatogonia, then also in the cytoplasm similarly to that seen after puberty. In CIS cells, DDX3Y was highly expressed and located predominantly in the nuclei. In invasive TGCT, significant DDX3Y expression was found in seminomas of the classical and spermatocytic type, but not in somatically differentiated non-seminomas, consistent with its germ-cell specific function. The fetal germ cell DDX3Y expression suggests a role in early spermatogonial proliferation and implies that, in men with AZFa deletion, germ cell depletion may begin prenatally. The strong expression of DDX3Y in CIS cells, but not in gonocytes, indicates phenotypic plasticity of CIS cells and suggests partial maturation to spermatogonia, likely due to their postpubertal microenvironment.

  8. Development of interspecies testicular germ-cell transplantation in flatfish.

    PubMed

    Pacchiarini, Tiziana; Sarasquete, Carmen; Cabrita, Elsa

    2014-06-01

    Interspecific testicular germ cell (TGC) transplantation was investigated in two commercial flatfish species. Testes from donor species (Senegalese sole) were evaluated using classical histological techniques (haematoxylin-eosin staining and haematoxylin-light green-orange G-acid fuchsine staining), in situ hybridisation and immunohistochemical analysis. Both Ssvasa1-2 mRNAs and SsVasa protein allowed the characterisation of TGCs, confirming the usefulness of the vasa gene in the detection of Senegalese sole TGCs. Xenogenic transplants were carried out using TGCs from one-year-old Senegalese sole into turbot larvae. Propidium iodide-SYBR-14 and 4',6'-diamidino-2-phenylindole (DAPI) staining showed that 87.98% of the extracted testicular cells were viable for microinjection and that 15.63% of the total recovered cells were spermatogonia. The vasa gene was characterised in turbot recipients using cDNA cloning. Smvasa mRNA was confirmed as a germ cell-specific molecular marker in this species. Smvasa expression analysis during turbot ontogeny was carried out before Senegalese sole TGC transplants into turbot larvae. Turbot larvae at 18 days after hatching (DAH) proved to be susceptible to manipulation procedures. High survival rates (83.75±15.90-100%) were obtained for turbot larvae at 27, 34 and 42 DAH. These data highlight the huge potential of this species for transplantation studies. Quantitative PCR was employed to detect Senegalese sole vasa mRNAs (Ssvasa1-2) in the recipient turbot larvae. The Ssvasa mRNAs showed a significant increase in relative expression in 42-DAH microinjected larvae three weeks after treatment, showing the proliferation of Senegalese sole spermatogonia in transplanted turbot larvae.

  9. Function of cyclins in regulating the mitotic and meiotic cell cycles in male germ cells

    PubMed Central

    Wolgemuth, Debra J.

    2014-01-01

    The specialized cell cycles that characterize various aspects of the differentiation of germ cells provide a unique opportunity to understand heretofore elusive aspects of the in vivo function of cell cycle regulators. Key components of the cell cycle machinery are the regulatory sub-units, the cyclins, and their catalytic partners, the cyclin-dependent kinases. Some of the cyclins exhibit unique patterns of expression in germ cells that suggest possible concomitant distinct functions, predictions that are being explored by targeted mutagenesis in mouse models. A novel, meiosis-specific function has been shown for one of the A-type cyclins, cyclin A1. Embryonic lethality has obviated understanding of the germline functions of cyclin A2 and cyclin B1, while yet other cyclins, although expressed at specific stages of germ cell development, may have less essential function in the male germline. PMID:19001847

  10. Murine somatic cell nuclear transfer using reprogrammed donor cells expressing male germ cell-specific genes.

    PubMed

    Kang, Hoin; Park, Jong Im; Roh, Sangho

    2016-01-01

    In vivo-matured mouse oocytes were enucleated, and a single murine embryonic fibroblast (control or reprogrammed by introducing extracts from murine testis tissue, which showed expression of male germ cell-specific genes) was injected into the cytoplasm of the oocytes. The rate of blastocyst development and expression levels of Oct-4, Eomes and Cdx-2 were not significantly different in both experimental groups. However, the expression levels of Nanog, Sox9 and Glut-1 were significantly increased when reprogrammed cells were used as donor nuclei. Increased expression of Nanog can be supportive of complete reprogramming of somatic cell nuclear transfer murine embryos. The present study suggested that donor cells expressing male germ cell-specific genes can be reconstructed and can develop into embryos with normal high expression of developmentally essential genes.

  11. Germ-cell culture conditions facilitate the production of mouse embryonic stem cells.

    PubMed

    Ramos-Ibeas, Priscila; Pericuesta, Eva; Fernández-González, Raúl; Gutiérrez-Adán, Alfonso; Ramírez, Miguel Ángel

    2014-09-01

    The derivation of embryonic stem-cell (ESC) lines from blastocysts is a very inefficient process. Murine ESCs are thought to arise from epiblast cells that are already predisposed to a primordial-germ-cell fate. During the process of ESC derivation from B6D2 F1 hybrid mice, if we first culture the embryo from the two-cell stage in medium supplemented with LIF, we improve the quality of the blastocyst. When the blastocyst is then cultured in a germ-line stem-cell culture medium (GSCm), we are able to more efficiently (28.3%) obtain quality ESC lines that have a normal karyotype, proper degree of chimerism, and exhibit germ-line transmission when microinjected into blastocysts. Although germ-cell-specific genes were expressed in all culture medium conditions, GSCm did not shift the transcriptome towards germ-cell specification. A correlation was further observed between ESC derivation efficiency and the expression of some imprinted genes and retrotransposable elements. In conclusion, the combination of LIF supplementation followed by culture in GSCm establishes a higher efficiency method for ESC derivation. © 2014 Wiley Periodicals, Inc.

  12. Germ cell pluripotency, premature differentiation and susceptibility to testicular teratomas in mice

    PubMed Central

    Heaney, Jason D.; Anderson, Ericka L.; Michelson, Megan V.; Zechel, Jennifer L.; Conrad, Patricia A.; Page, David C.; Nadeau, Joseph H.

    2012-01-01

    Testicular teratomas result from anomalies in germ cell development during embryogenesis. In the 129 family of inbred strains of mice, teratomas initiate around embryonic day (E) 13.5 during the same developmental period in which female germ cells initiate meiosis and male germ cells enter mitotic arrest. Here, we report that three germ cell developmental abnormalities, namely continued proliferation, retention of pluripotency, and premature induction of differentiation, associate with teratoma susceptibility. Using mouse strains with low versus high teratoma incidence (129 versus 129-Chr19MOLF/Ei), and resistant to teratoma formation (FVB), we found that germ cell proliferation and expression of the pluripotency factor Nanog at a specific time point, E15.5, were directly related with increased tumor risk. Additionally, we discovered that genes expressed in pre-meiotic embryonic female and adult male germ cells, including cyclin D1 (Ccnd1) and stimulated by retinoic acid 8 (Stra8), were prematurely expressed in teratoma-susceptible germ cells and, in rare instances, induced entry into meiosis. As with Nanog, expression of differentiation-associated factors at a specific time point, E15.5, increased with tumor risk. Furthermore, Nanog and Ccnd1, genes with known roles in testicular cancer risk and tumorigenesis, respectively, were co-expressed in teratoma-susceptible germ cells and tumor stem cells, suggesting that retention of pluripotency and premature germ cell differentiation both contribute to tumorigenesis. Importantly, Stra8-deficient mice had an 88% decrease in teratoma incidence, providing direct evidence that premature initiation of the meiotic program contributes to tumorigenesis. These results show that deregulation of the mitotic-meiotic switch in XY germ cells contributes to teratoma initiation. PMID:22438569

  13. An Integrative Omics Strategy to Assess the Germ Cell Secretome and to Decipher Sertoli-Germ Cell Crosstalk in the Mammalian Testis

    PubMed Central

    Lavigne, Régis; Hernio, Nolwen; Teixeira-Gomes, Ana-Paula; Dacheux, Jean-Louis; Pineau, Charles

    2014-01-01

    Mammalian spermatogenesis, which takes place in complex testicular structures called seminiferous tubules, is a highly specialized process controlled by the integration of juxtacrine, paracrine and endocrine information. Within the seminiferous tubules, the germ cells and Sertoli cells are surrounded by testicular fluid (TF), which probably contains most of the secreted proteins involved in crosstalk between these cells. It has already been established that germ cells can modulate somatic Sertoli cell function through the secretion of diffusible factors. We studied the germ cell secretome, which was previously considered inaccessible, by analyzing the TF collected by microsurgery in an “integrative omics” strategy combining proteomics, transcriptomics, genomics and interactomics data. This approach identified a set of proteins preferentially secreted by Sertoli cells or germ cells. An interaction network analysis revealed complex, interlaced cell-cell dialog between the secretome and membranome of seminiferous cells, mediated via the TF. We then focused on germ cell-secreted candidate proteins, and we identified several potential interacting partners located on the surface of Sertoli cells. Two interactions, APOH/CDC42 and APP/NGFR, were validated in situ, in a proximity ligation assay (PLA). Our results provide new insight into the crosstalk between germ cells and Sertoli cells occurring during spermatogenesis. Our findings also demonstrate that this “integrative omics” strategy is powerful enough for data mining and highlighting meaningful cell-cell communication events between different types of cells in a complex tissue, via a biological fluid. This integrative strategy could be applied more widely, to gain access to secretomes that have proved difficult to study whilst avoiding the limitations of in vitro culture. PMID:25111155

  14. Production of loach (Misgurnus anguillicaudatus) germ-line chimera using transplantation of primordial germ cells isolated from cryopreserved blastomeres.

    PubMed

    Yasui, G S; Fujimoto, T; Sakao, S; Yamaha, E; Arai, K

    2011-08-01

    An efficient procedure for the cryopreservation of fish blastomeres followed by restoration through germ-line chimera formation was established. Blastomeres of the loach (Misgurnus anguillicaudatus) were cryopreserved in 250-µL straws in Eagle's minimum essential medium with various concentrations of dimethyl-sulfoxide (0, 5, 10, 15, and 20%), and the best concentration was combined with glycerol (1, 2, and 4%) and external cryoprotectants (1 or 2% sucrose; 2, 5, or 10% fetal bovine serum; 1 or 2% BSA). Postthaw viability of the blastomeres was used to optimize cryopreservation conditions. Donor blastomeres were injected with zebrafish green fluorescence protein-nos1 3' untranslated region mRNA and biotin dextran before cryopreservation in the optimal freeze medium. Host embryos were injected with zebrafish DsRed-nos1 3' untranslated region mRNA and reared to the blastula stage. Donor blastomeres were thawed at 25 °C for 10 s and transplanted to the host embryos either immediately or after incubation for 16 h at 20 °C. Donor and host primordial germ cell migration was visualized with fluorescent imaging during the early stages of embryogenesis, and also by histology in 4-d-old embryos. Transplantation of blastomeres immediately after thawing gave decreased hatching rates (approximately 3%) and generated a smaller percentage of germ-line chimeras (approximately 1.1%). In contrast, incubation of a cryopreserved sample for 16 h followed by transplantation of the green fluorescence protein-positive blastomeres improved the hatching rate to 90%, and successfully produced presumable germ-line chimeras at a rate of 16.5%. The improved survival rates and germ-line chimerism may be an effective method for gene banking and subsequent reconstitution of endangered fish genotypes. © 2011 American Society of Animal Science. All rights reserved.

  15. In vivo analysis of germ cell apoptosis reveals the existence of stage-specific 'social' control of germ cell death in the seminiferous epithelium.

    PubMed

    Blanco-Rodríguez, J; Martínez-García, C

    1997-12-01

    It has become clear in recent years that programmed cell death is regulated during development by signals from other cells. Nevertheless, compared to the 'social' control of cell proliferation, relatively little is known about the 'social' control of cell death in other systems. Since in a previous study we showed that induced germ cell apoptosis occurs at specific stages of the spermatogenic cycle, in this study we aimed to ascertain the existence of supracellular control of germ cell death during spermatogenesis. Therefore, the TUNEL technique has been used to analyse whether all of the different germ cell types are induced to die at these specific stages in animals injected intratesticularly with one of several inducers of apoptosis. Our findings suggest that all of the investigated agents trigger apoptosis in all the diverse progenies of germ cells existing at stages I, XII or XIV of the spermatogenic cycle. In contrast, at most other stages the number of apoptotic cells was similar to that found in control animals. These data are consistent with the existence of an intercellular control of germ cell death during spermatogenesis. We conclude that the seminiferous epithelium provides a suitable in vivo model to study the mechanisms underlying the 'social' control of apoptosis.

  16. Management of clinical stage I nonseminomatous germ cell tumors.

    PubMed

    Isharwal, Sumit; Risk, Michael C

    2014-09-01

    Therapeutic options for clinical stage I nonseminomatous germ cell tumor include active surveillance, adjuvant chemotherapy and retroperitoneal lymph node dissection (RPLND). Lymphovascular invasion (LVI) determines risk of recurrence, as those without LVI have 15% risk of relapse on surveillance while those with LVI have a 50% risk. This stratifies patients into high risk(LVI+) and low risk(LVI-) groups which direct treatment recommendations. Surveillance is preferred for those with low risk disease, and is an option for those with high risk disease, as at least half are over-treated with other options. Adjuvant chemotherapy is an option for all patients as it can eradicate micrometastatic disease and reduce recurrence by at least 90%. RPLND benefits patients with low volume retroperitoneal disease with a cure rate of RPLND alone at approximately 70%. All three treatment modalities have similar survival rates approaching 100% but differing potential morbidities, which, along with patient preferences and compliance, should guide treatment decisions.

  17. The challenge of poor-prognosis germ cell tumors.

    PubMed

    Toner, Guy C

    2007-05-01

    Patients who have a poor prognosis can be identified at presentation by well-defined prognostic factors. Prognostic groups as defined by the International Germ Cell Consensus Classification should be used in the clinic, in clinical trials, and when reporting results. No systemic treatment has been shown to improve outcome compared with four cycles of chemotherapy composed of bleomycin, etoposide, and cisplatin, which remains the standard of care. Surgery to resect residual masses after chemotherapy and in the salvage setting is a vital component of optimal care. The best outcomes occur with treatment at a center with experience and expertise in their management. Further major improvements are likely to require novel systemic therapies rather than modifications of existing approaches.

  18. Germ cell mutagenicity of phthalic acid in mice.

    PubMed

    Jha, A M; Singh, A C; Bharti, M

    1998-12-03

    Mutagenicity of phthalic acid was evaluated by employing dominant lethal mutation and sperm head abnormality assays in male Swiss albino mice. For the dominant lethal mutation assay, adult male mice received a single intraperitoneal (i.p.) injection of either 40 mg or 80 mg/kg b.w. of phthalic acid for 5 consecutive days. For the sperm head abnormality assay, the mice were treated with 50, 100, 150, 200 and 300 mg/kg b.w. as a single i.p. injection. Treatment of adult male mice with phthalic acid resulted in induction of dominant lethal mutations and abnormal sperm heads. The results obtained indicate that phthalic acid is a germ cell mutagen.

  19. Emerging Therapeutic Targets for Male Germ Cell Tumors.

    PubMed

    Fankhauser, Christian Daniel; Honecker, Friedemann; Beyer, Jörg; Bode, Peter Karl

    2015-12-01

    Male germ cell tumors (GCTs) are curable cancers, yet 10-15 % of patients with metastatic disease fail cisplatin-based first-line treatments. While therapeutic options have increased for various other cancers, little progress has been made in the management of GCT in the last decades. A better understanding of the molecular alterations underlying the disease and identification of new therapeutic targets are needed. Several phase I/II studies with promising new agents are ongoing or have been completed, but most of those trials have been small and have not included translational research. Therefore, molecular profiles predictive for response or new agents have not been identified in male GCT so far. The purpose of this review is to highlight emerging targets and therapies with the potential to improve systemic treatment of metastatic male GCT and to develop strategies for future clinical trials.

  20. NOTCH1 gain of function in germ cells causes failure of spermatogenesis in male mice.

    PubMed

    Huang, Zaohua; Rivas, Bryan; Agoulnik, Alexander I

    2013-01-01

    NOTCH1 is a member of the NOTCH receptor family, a group of single-pass trans-membrane receptors. NOTCH signaling is highly conserved in evolution and mediates communication between adjacent cells. NOTCH receptors have been implicated in cell fate determination, as well as maintenance and differentiation of stem cells. In the mammalian testis expression of NOTCH1 in somatic and germ cells has been demonstrated, however its role in spermatogenesis was not clear. To study the significance of NOTCH1 in germ cells, we applied a cre/loxP approach in mice to induce NOTCH1 gain- or loss-of function specifically in male germ cells. Using a Stra8-icre transgene we produced mice with conditional activation of the NOTCH1 intracellular domain (NICD) in germ cells. Spermatogenesis in these mutants was progressively affected with age, resulting in decreased testis weight and sperm count. Analysis of downstream target genes of NOTCH1 signaling showed an increased expression of Hes5, with a reduction of the spermatogonial differentiation marker, Neurog3 expression in the mutant testis. Apoptosis was significantly increased in mouse germ cells with the corresponding elevation of pro-apoptotic Trp53 and Trp63 genes' expression. We also showed that the conditional germ cell-specific ablation of Notch1 had no effect on spermatogenesis or male fertility. Our data suggest the importance of NOTCH signaling regulation in male germ cells for their survival and differentiation.

  1. Involvement of Fas/Fas-L and Bax/Bcl-2 systems in germ cell death following immunization with syngeneic testicular germ cells in mice.

    PubMed

    Kuerban, Maimaiti; Naito, Munekazu; Hirai, Shuichi; Terayama, Hayato; Qu, Ning; Musha, Muhetaerjiang; Ikeda, Ayumi; Koji, Takehiko; Itoh, Masahiro

    2012-01-01

    Experimental autoimmune orchitis (EAO) is characterized by T cell-dependent lymphocytic inflammation and seminiferous tubule damage, which can result in the death of germ cells. The aim of the present study is to investigate the roles of the Fas/Fas-L and Bax/Bcl-2 systems in the death of germ cells in mice with EAO that is induced by immunization with syngeneic testicular germ cells (TGC). The results using real-time reverse transcription-polymerase chain reaction and immunostaining show that many terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining germ cells were present in seminiferous tubules during the active inflammation stage, and these cells were persistently observed in the seminiferous epithelium until the postactive inflammation stage. Intratesticular mRNA expression levels of both Fas and Bax were increased during the active inflammation stage and were dramatically decreased during the post-active inflammation stage. In contrast, the intratesticular mRNA expression levels of both Fas-L and Bcl-2 did not show significant changes during the active inflammation stage but showed extreme increases during the post-active inflammation stage. Immunohistochemically, some Fas- and Bax-positive germ cells were detected during the active inflammation stage, but these were hardly found during the post-active inflammation stage. In contrast, some Fas-L- and Bcl-2-positive germ cells were found during the active inflammation stage, and many of these were also observed during the post-active inflammation stage. These results indicate that germ cell death during TGC-induced EAO is mediated by the Fas/Fas-L and Bax/Bcl-2 systems during the active inflammation stage but not during the post-active inflammation stage.

  2. Reproductive function after treatment of ovarian germ cell malignancy.

    PubMed

    Anita, A N; Rushdan, M N

    2012-02-01

    This study was undertaken to evaluate the reproductive and oncologic outcomes of patients diagnosed with Ovarian Germ Cell Malignancy (OGCM) who underwent fertility preserving surgery and adjuvant chemotherapy treated in Gynaecology Oncology Unit, Sultanah Bahiyah Hospital, Kedah, Malaysia. We retrospectively reviewed 33 patients who had fertility preserving surgery and adjuvant chemotherapy in our center from 2000 - 2010. Gynaecology oncology record and histopathology database were reviewed. Patients were contacted, assessed and interviewed via telephone using standardized questionnaire to assess their menstrual, reproductive function and disease status after treatment, post therapeutic status of pregnancy or delivery and overall survival. Thirty three patients diagnosed with OGCM underwent unilateral salphingo oophorectomy and staging surgery followed by adjuvant chemotherapy (BEP regimen). The mean age at presentation was 19.8 years (range, 9 -34 years). Histological subtypes were 21.2% dysgerminoma, 21.2% immature teratoma, 42.4% yolk sac tumour and 15.2% mixed germ cell tumour. After treatment, 71.4% resumed their menstrual cycles within 6 months. During follow up, 5 patients conceived with 5 live birth deliveries and 3 miscarriages (3 patients had two pregnancies). The overall survival rate was 87.9% with median follow up of 45.2 months. 30.3% of patient had disease recurrence with median disease free interval of 5 months while 6.0% had disease progression despite of adjuvant chemotherapy. One of the most important adverse prognostic factors for recurrence and disease progression is Yolk sac tumour (non DSG/IMT) histotype. Fertility preserving surgery and adjuvant chemotherapy appear to have little effect on fertility and menstrual cycle with a good overall survival. Patients diagnosed with histopathological yolk sac tumour element had poor outcome and perhaps need more aggressive and longer adjuvant therapy.

  3. The C. elegans germ line: a model for stem cell biology

    PubMed Central

    Hubbard, E. Jane Albert

    2009-01-01

    Like many stem cell systems, the C. elegans germ line contains a self-renewing germ cell population that is maintained by a niche. Although the exact cellular mechanism for self-renewal is not yet known, three recent studies shed considerable light on the cell-cycle behavior of germ cells, including a support for significant and plastic renewal potential. This review brings together the results of the three recent cell-based studies, places them in the context of previous work, and discusses future perspectives for the field. PMID:17948315

  4. [Reconsidering the roles of female germ cells in ovarian development and folliculogenesis].

    PubMed

    Guigon, Céline J; Cohen-Tannoudji, Michel

    2011-01-01

    The production of fertilizable ova is the consequence of multiple events that start as soon as ovarian development and culminate at the time of ovulation. Throughout their development, germ cells are associated with companion somatic cells, which ensure germ cell survival, growth and maturation. Data obtained in vitro and in vivo on several animal models of germ cell depletion have led to uncover the many roles of germ cells on both ovarian development and folliculogenesis. During ovarian development, germ cells become progressively enclosed within epithelial structures called "ovigerous cords" constituted by pregranulosa cells, lined by a basement membrane. At the end of ovarian development, ovigerous cords fragment into primordial follicles, which are epithelial units constituted by an oocyte surrounded by a single layer of granulosa cells. Germ cells are necessary for the fragmentation of ovigerous cords into follicles, since in their absence, no follicle will form. Germ cells also ensure the differentiation of the ovarian somatic lineage, and they may inhibit the testis-differentiating pathway by preventing the conversion of pregranulosa cells into Sertoli cells, their counterpart in the testis. Regularly, primordial follicles are recruited into the growing follicle pool and initiate their growth. They develop through primary, preantral, antral and preovulatory stages before being ovulated. Interestingly, the action of the oocyte on companion somatic cells tightly depends on the follicular stage. In primordial follicles, the oocyte prevents the transdifferentiation of granulosa cells into cells resembling Sertoli cells. By contrast, as soon as the follicle enters growth, the oocyte regulates the functional differentiation of granulosa cells and at the latest stages, it prevents their premature maturation into luteal cells. Overall, these data demonstrate that the female germ cell act on companion somatic cells to regulate ovarian development and

  5. Recent advances in molecular and cell biology of testicular germ-cell tumors.

    PubMed

    Chieffi, Paolo

    2014-01-01

    Testicular germ-cell tumors (TGCTs) are the most frequent solid malignant tumors in men 20-40 years of age and the most frequent cause of death from solid tumors in this age group. TGCTs comprise two major histologic groups: seminomas and nonseminomas germ-cell tumors (NSGCTs). NSGCTs can be further divided into embryonal, carcinoma, Teratoma, yolk sac tumor, and choriocarcinoma. Seminomas and NSGCTs present significant differences in clinical features, therapy, and prognosis, and both show characteristics of the primordial germ cells. Many discovered biomarkers including OCT3/4, SOX2, SOX17, HMGA1, Nek2, GPR30, Aurora-B, estrogen receptor β, and others have given further advantages to discriminate between histological subgroups and could represent useful novel molecular targets for antineoplastic strategies. More insight into the pathogenesis of TGCTs is likely to improve disease management not only to better treatment of these tumors but also to a better understanding of stem cells and oncogenesis.

  6. The cytogenetic theory of the pathogenesis of human adult male germ cell tumors. Review article.

    PubMed

    Chaganti, R S; Houldsworth, J

    1998-01-01

    Human male germ cell tumors (GCTs) represent a biological paradox because, in order to develop into a pluripotential tumor, a germ cell destined to a path of limited or no proliferation must acquire the potential for unlimited proliferation. In addition, it must acquire the ability to elicit embryonal differentiation patterns without the reciprocal inputs from fertilization and the imprinting-associated genomic changes which are a part of normal embryonal development. Although much speculated about, the genetic mechanisms underlying these properties of male GCTs remain enigmatic. Recent cytogenetic and molecular genetic analyses of these tumors are providing new insights and new testable hypotheses. Based on our recent work, we propose two such hypotheses. One relates to the mechanism of germ cell transformation and germ cell tumor development. We suggest that the invariable 12p amplification noted as early as in carcinoma in situ/intratubular germ cell neoplasia (CIS/ITGCN) lesions leads to deregulated overexpression of cyclin D2, a cell cycle G1/S checkpoint regulator with oncogeneic potential. Such overexpression reinitiates the cell cycle. We visualize this happening during the pachytene stage of meiosis through aberrant recombinational events which lead to 12p amplification. The other hypothesis relates to the origin of primary extragonadal GCTs. By comparing cytogenetic changes in primary mediastinal versus gonadal lesions, we propose that, in contrast to long-standing speculation that primary extra-gonadal tumors arise from embryonally misplaced primordial germ cells, these lesions arise from migration of transformed gonadal germ cells.

  7. DNA damage in germ cells induces an innate immune response that triggers systemic stress resistance.

    PubMed

    Ermolaeva, Maria A; Segref, Alexandra; Dakhovnik, Alexander; Ou, Hui-Ling; Schneider, Jennifer I; Utermöhlen, Olaf; Hoppe, Thorsten; Schumacher, Björn

    2013-09-19

    DNA damage responses have been well characterized with regard to their cell-autonomous checkpoint functions leading to cell cycle arrest, senescence and apoptosis. In contrast, systemic responses to tissue-specific genome instability remain poorly understood. In adult Caenorhabditis elegans worms germ cells undergo mitotic and meiotic cell divisions, whereas somatic tissues are entirely post-mitotic. Consequently, DNA damage checkpoints function specifically in the germ line, whereas somatic tissues in adult C. elegans are highly radio-resistant. Some DNA repair systems such as global-genome nucleotide excision repair (GG-NER) remove lesions specifically in germ cells. Here we investigated how genome instability in germ cells affects somatic tissues in C. elegans. We show that exogenous and endogenous DNA damage in germ cells evokes elevated resistance to heat and oxidative stress. The somatic stress resistance is mediated by the ERK MAP kinase MPK-1 in germ cells that triggers the induction of putative secreted peptides associated with innate immunity. The innate immune response leads to activation of the ubiquitin-proteasome system (UPS) in somatic tissues, which confers enhanced proteostasis and systemic stress resistance. We propose that elevated systemic stress resistance promotes endurance of somatic tissues to allow delay of progeny production when germ cells are genomically compromised.

  8. Mechano-logical model of C. elegans germ line suggests feedback on the cell cycle

    PubMed Central

    Atwell, Kathryn; Qin, Zhao; Gavaghan, David; Kugler, Hillel; Hubbard, E. Jane Albert; Osborne, James M.

    2015-01-01

    The Caenorhabditis elegans germ line is an outstanding model system in which to study the control of cell division and differentiation. Although many of the molecules that regulate germ cell proliferation and fate decisions have been identified, how these signals interact with cellular dynamics and physical forces within the gonad remains poorly understood. We therefore developed a dynamic, 3D in silico model of the C. elegans germ line, incorporating both the mechanical interactions between cells and the decision-making processes within cells. Our model successfully reproduces key features of the germ line during development and adulthood, including a reasonable ovulation rate, correct sperm count, and appropriate organization of the germ line into stably maintained zones. The model highlights a previously overlooked way in which germ cell pressure may influence gonadogenesis, and also predicts that adult germ cells might be subject to mechanical feedback on the cell cycle akin to contact inhibition. We provide experimental data consistent with the latter hypothesis. Finally, we present cell trajectories and ancestry recorded over the course of a simulation. The novel approaches and software described here link mechanics and cellular decision-making, and are applicable to modeling other developmental and stem cell systems. PMID:26428008

  9. Testicular structure and germ cells morphology in salamanders

    PubMed Central

    Uribe, Mari Carmen; Mejía-Roa, Víctor

    2014-01-01

    Testes of salamanders or urodeles are paired elongated organs that are attached to the dorsal wall of the body by a mesorchium. The testes are composed of one or several lobes. Each lobe is morphologically and functionally a similar testicular unit. The lobes of the testis are joined by cords covered by a single peritoneal epithelium and subjacent connective tissue. The cords contain spermatogonia. Spermatogonia associate with Sertoli cells to form spermatocysts or cysts. The spermatogenic cells in a cyst undergo their development through spermatogenesis synchronously. The distribution of cysts displays the cephalo-caudal gradient in respect to the stage of spermatogenesis. The formation of cysts at cephalic end of the testis causes their migration along the lobules to the caudal end. Consequently, the disposition in cephalo-caudal regions of spermatogenesis can be observed in longitudinal sections of the testis. The germ cells are spermatogonia, diploid cells with mitotic activity; primary and second spermatocytes characterized by meiotic divisions that develop haploid spermatids; during spermiogenesis the spermatids differentiate to spermatozoa. During spermiation the cysts open and spermatozoa leave the testicular lobules. After spermiation occurs the development of Leydig cells into glandular tissue. This glandular tissue regressed at the end of the reproductive cycle. PMID:26413406

  10. Control over the morphology and segregation of Zebrafish germ cell granules during embryonic development

    PubMed Central

    Strasser, Markus J; Mackenzie, Natalia C; Dumstrei, Karin; Nakkrasae, La-Iad; Stebler, Jürg; Raz, Erez

    2008-01-01

    Background Zebrafish germ cells contain granular-like structures, organized around the cell nucleus. These structures share common features with polar granules in Drosophila, germinal granules in Xenopus and chromatoid bodies in mice germ cells, such as the localization of the zebrafish Vasa, Piwi and Nanos proteins, among others. Little is known about the structure of these granules as well as their segregation in mitosis during early germ-cell development. Results Using transgenic fish expressing a fluorescently labeled novel component of Zebrafish germ cell granules termed Granulito, we followed the morphology and distribution of the granules. We show that whereas these granules initially exhibit a wide size variation, by the end of the first day of development they become a homogeneous population of medium size granules. We investigated this resizing event and demonstrated the role of microtubules and the minus-end microtubule dependent motor protein Dynein in the process. Last, we show that the function of the germ cell granule resident protein the Tudor domain containing protein-7 (Tdrd7) is required for determination of granule morphology and number. Conclusion Our results suggest that Zebrafish germ cell granules undergo a transformation process, which involves germ cell specific proteins as well as the microtubular network. PMID:18507824

  11. Fertility facts: male and female germ cell development requires translational control by CPEB.

    PubMed

    Gebauer, F; Hentze, M W

    2001-08-01

    In the August issue of Developmental Cell, Tay and Richter examine the consequences of eliminating CPEB function in mice. Their studies reveal an important role for this translational regulator at the pachytene stage of germ cell differentiation.

  12. Apoptosis mediated by phosphatidylserine externalization in the elimination of aneuploid germ cells during human spermatogenesis.

    PubMed

    Garcia-Quevedo, L; Blanco, J; Sarrate, Z; Vidal, F

    2014-11-01

    It has been described that aneuploidies trigger cell cycle checkpoints leading to apoptosis. The aim of this study was to assess the relationship between the presence of chromosomal abnormalities and apoptosis in germ cells and in Sertoli cells. Fourteen diagnostic testicular biopsies from infertile patients were processed following a sequential methodology, which included enzymatic disaggregation, apoptotic staining, cell sorting, cell fixation, and fluorescent in situ hybridization analysis. The chromosome constitution of germ cells (interphase pre-meiotic germ cells, meiotic figures, post-reductional germ cells, and spermatozoa) and Sertoli cells was evaluated in non-sorted and flow-sorted cell populations (apoptotic and viable). The mean percentage of aneuploidy was compared between the three fractions in each cell type using a Kruskal-Wallis test. If significant results were obtained, a two-by-two Chi-squared test was performed. There were significant differences between the apoptotic fraction and the viable and non-sorted fractions in the pre-meiotic germ cells (p < 0.01). In the remaining cell types, no association between the presence of aneuploidy and apoptotic processes was observed, even in the case of post-reductional germ cells in which we detected the highest rates of aneuploidy regardless of the fraction analyzed. From our data, it can be inferred that most of the aneuploid post-reductional germ cells are efficiently removed from the testicular epithelium without differentiating into spermatozoa. Our results suggest that the elimination of aneuploid testicular epithelial cells is triggered by different mechanisms. Accordingly, the cellular elimination of aneuploid germ cells beyond the blood-testis barrier does not involve phosphatidylserine externalization. © 2014 American Society of Andrology and European Academy of Andrology.

  13. Differentiation of early germ cells from human skin-derived stem cells without exogenous gene integration

    PubMed Central

    Ge, Wei; Ma, Hua-Gang; Cheng, Shun-Feng; Sun, Yuan-Chao; Sun, Li-Lan; Sun, Xiao-Feng; Li, Lan; Dyce, Paul; Li, Julang; Shi, Qing-Hua; Shen, Wei

    2015-01-01

    Infertility has long been a difficult issue for many couples. The successful differentiation of germ cells and live progeny from pluripotent stem cells brings new hope to the couples suffering with infertility. Here we successfully isolated human fetus skin-derived stem cells (hfSDSCs) from fetus skin tissue and demonstrated that hfSDSCs can be differentiated into early human germ cell-like cells (hGCLCs). These cells express human germ cell markers DAZL and VASA. Moreover, these pluripotent stem cell-derived hGCLCs are free of exogenous gene integration. When hfSDSCs were differentiated in porcine follicle fluid (PFF) conditioned media, which has been shown to promote the differentiation of mouse and porcine SDSCs into oocyte-like cells (OLCs), we observed some vesicular structures formed from hfSDSCs. Moreover, when hfSDSCs were cultured with specific conditioned media, we observed punctate and elongated SCP3 staining foci, indicating the initiation of meiosis. Ploidy analysis and fluorescent in situ hybridization (FISH) analysis indicated that a small percentage of putative 1N populations formed from hfSDSCs when compared with positive controls. In conclusion, our data here, for the first time, demonstrated that hfSDSCs possess the differentiation potential into germ lines, and they may differentiate both male and female hGCLCs in vitro under appropriate conditions. PMID:26347377

  14. Most regions of mouse epididymis are able to phagocytose immature germ cells.

    PubMed

    Ramos-Ibeas, P; Pericuesta, E; Fernández-González, R; Ramírez, M A; Gutierrez-Adan, A

    2013-01-01

    The role of the epididymis as a quality control organ in preventing infertile gametes entering the ejaculate has been extensively explored, and it has been suggested that a specific region of mammalian epididymis is able to phagocytose abnormal germ cells. This study examines whether the epithelium of certain zones of the mouse epididymis can act as a selection barrier by removing immature germ cells from the lumen by phagocytosis. To detect the presence of immature germ cells in the epididymis, we generated transgenic mice expressing enhanced green fluorescent protein under the deleted in azoospermia-like (mDazl) promoter to easily identify immature germ cells under fluorescence microscopy. Using this technique, we observed that during the first stage of spermatogenesis in prepuberal mice, a wave of immature germ cells is released into the epididymis and that the immature epididymis is not able to react to this abnormal situation. By contrast, when immature germ cells were artificially released into the epididymis in adult mice, a phagocytic response was observed. Phagosomes appeared inside principal cells of the epididymal epithelium and were observed to contain immature germ cells at different degradation stages in different zones of the epididymis, following the main wave of immature germ cells. In this paper, we describe how the epididymal epithelium controls sperm quality by clearing immature germ cells in response to their artificially induced massive shedding into the epididymal lumen. Our observations indicate that this phenomenon is not restricted to a given epididymis region and that phagocytic capacity is gradually acquired during epididymal development.

  15. The human VASA gene is specifically expressed in the germ cell lineage

    PubMed Central

    Castrillon, Diego H.; Quade, Bradley J.; Wang, T. Y.; Quigley, Catherine; Crum, Christopher P.

    2000-01-01

    To understand the origins and function of the human germ cell lineage and to identify germ cell-specific markers we have isolated a human ortholog of the Drosophila gene vasa. The gene was mapped to human chromosome 5q (near the centromere) by radiation hybrid mapping. We show by Northern analysis of fetal and adult tissues that expression of the human VASA gene is restricted to the ovary and testis and is undetectable in somatic tissues. We generated polyclonal antibodies that bind to the VASA protein in formalin-fixed, paraffin-embedded tissue and characterized VASA protein expression in human germ cells at various stages of development. The VASA protein is cytoplasmic and expressed in migratory primordial germ cells in the region of the gonadal ridge. VASA protein is present in fetal and adult gonadal germ cells in both males and females and is most abundant in spermatocytes and mature oocytes. The gene we have isolated is thus a highly specific marker of germ cells and should be useful for studies of human germ cell determination and function. PMID:10920202

  16. Chick stem cells: Current progress and future prospects

    PubMed Central

    Intarapat, Sittipon; Stern, Claudio D.

    2013-01-01

    Chick embryonic stem cells (cESCs) can be derived from cells obtained from stage X embryos (blastoderm stage); these have the ability to contribute to all somatic lineages in chimaeras, but not to the germ line. However, lines of stem cells that are able to contribute to the germ line can be established from chick primordial germ cells (cPGCs) and embryonic germ cells (cEGCs). This review provides information on avian stem cells, emphasizing different sources of cells and current methods for derivation and culture of pluripotent cells from chick embryos. We also review technologies for isolation and derivation of chicken germ cells and the production of transgenic birds. PMID:24103496

  17. The fog-3 gene and regulation of cell fate in the germ line of Caenorhabditis elegans

    SciTech Connect

    Ellis, R.; Kimble, J.

    1995-02-01

    In the nematode Caenorhabditis elegans, germ cells normally adopt one of three fates: mitosis, spermatogenesis or oogenesis. We have identified and characterized the gene fog-3, which is required for germ cells to differentiate as sperm rather than as oocytes. Analysis of double mutants suggests that fog-3 is absolutely required for spermatogenesis and acts at the end of the regulatory hierarchy controlling sex determination for the germ line. By contrast, mutations in fog-3 do not alter the sexual identity of other tissues. We also have characterized the null phenotype of fog-1, another gene required for spermatogenesis; we demonstrate that it too controls the sexual identity of germ cells but not of other tissues. Finally, we have studied the same interaction of these two fog genes with gld-1, a gene required for germ cells to undergo oogenesis rather than mitosis. On the basis of these results, we propose that germ-cell fate might be controlled by a set of inhibitory interactions among genes that specify one of three fates: mitosis, spermatogenesis or oogenesis. Such a regulatory network would link the adoption of one germ-cell fate to the suppression of the other two. 68 refs., 7 figs., 6 tabs.

  18. The Fog-3 Gene and Regulation of Cell Fate in the Germ Line of Caenorhabditis Elegans

    PubMed Central

    Ellis, R. E.; Kimble, J.

    1995-01-01

    In the nematode Caenorhabditis elegans, germ cells normally adopt one of three fates: mitosis, spermatogenesis or oogenesis. We have identified and characterized the gene fog-3, which is required for germ cells to differentiate as sperm rather than as oocytes. Analysis of double mutants suggests that fog-3 is absolutely required for spermatogenesis and acts at the end of the regulatory hierarchy controlling sex determination for the germ line. By contrast, mutations in fog-3 do not alter the sexual identity of other tissues. We also have characterized the null phenotype of fog-1, another gene required for spermatogenesis; we demonstrate that it too controls the sexual identity of germ cells but not of other tissues. Finally, we have studied the interaction of these two fog genes with gld-1, a gene required for germ cells to undergo oogenesis rather than mitosis. On the basis of these results, we propose that germ-cell fate might be controlled by a set of inhibitory interactions among genes that specify one of three fates: mitosis, spermatogenesis or oogenesis. Such a regulatory network would link the adoption of one germ-cell fate to the suppression of the other two. PMID:7713418

  19. Chemotherapy for Good-Risk Nonseminomatous Germ Cell Tumors: Current Concepts and Controversies.

    PubMed

    In, Gino; Dorff, Tanya

    2015-08-01

    The rate of diagnosis of germ cell tumors has remained fairly constant. By the International Germ Cell Cancer Consensus Classification, roughly 60% of all metastatic germ cell tumors are classified as good risk. This group of patients has an excellent prognosis, with greater than 90% expectation of cure. Treatment standards have not changed much in recent years. This article focuses on key concepts in the development of the currently accepted first-line regimens and addresses some evolving areas of interest, if not controversy.

  20. Acute Leukemia and Concurrent Mediastinal Germ Cell Tumor: Case Report and Literature Review.

    PubMed

    Maese, Luke; Li, K David; Xu, Xinjie; Afify, Zeinab; Paxton, Christian N; Putnam, Angelica

    2017-04-01

    There is a known association of primary nonseminomatous mediastinal germ cell tumors (NSMGCT) and hematologic malignancy in younger males not linked to treatment. When combined these two rare entities convey a very poor prognosis. Here we report a 16-year-old male with an anterior mediastinal mass diagnosed as a malignant germ cell tumor based on elevation of serologic markers. He was found to have acute leukemia with megakaryocytic differentiation several days later. We focus our report on the pathologic findings, including a review of the literature, and a novel molecular analysis of the germ cell tumor.

  1. Mouse oocytes differentiate through organelle enrichment from sister cyst germ cells.

    PubMed

    Lei, Lei; Spradling, Allan C

    2016-04-01

    Oocytes differentiate in diverse species by receiving organelles and cytoplasm from sister germ cells while joined in germline cysts or syncytia. Mouse primordial germ cells form germline cysts, but the role of cysts in oogenesis is unknown. We find that mouse germ cells receive organelles from neighboring cyst cells and build a Balbiani body to become oocytes, whereas nurselike germ cells die. Organelle movement, Balbiani body formation, and oocyte fate determination are selectively blocked by low levels of microtubule-dependent transport inhibitors. Membrane breakdown within the cyst and an apoptosis-like process are associated with organelle transfer into the oocyte, events reminiscent of nurse cell dumping in Drosophila We propose that cytoplasmic and organelle transport plays an evolutionarily conserved and functionally important role in mammalian oocyte differentiation. Copyright © 2016, American Association for the Advancement of Science.

  2. Light and electron microscopic analyses of Vasa expression in adult germ cells of the fish medaka.

    PubMed

    Yuan, Yongming; Li, Mingyou; Hong, Yunhan

    2014-07-15

    Germ cells of diverse animal species have a unique membrane-less organelle called germ plasm (GP). GP is usually associated with mitochondria and contains RNA binding proteins and mRNAs of germ genes such as vasa. GP has been described as the mitochondrial cloud (MC), intermitochondrial cement (IC) and chromatoid body (CB). The mechanism underlying varying GP structures has remained incompletely understood. Here we report the analysis of GP through light and electron microscopy by using Vasa as a marker in adult male germ cells of the fish medaka (Oryzias latipes). Immunofluorescence light microscopy revealed germ cell-specific Vasa expression. Vasa is the most abundant in mitotic germ cells (oogonia and spermatogonia) and reduced in meiotic germ cells. Vasa in round spermatids exist as a spherical structure reminiscent of CB. Nanogold immunoelectron microscopy revealed subcellular Vasa redistribution in male germ cells. Vasa in spermatogonia concentrates in small areas of the cytoplasm and is surrounded by mitochondria, which is reminiscent of MC. Vasa is intermixed with mitochondria to form IC in primary spermatocytes, appears as the free cement (FC) via separation from mitochondria in secondary spermatocyte and becomes condensed in CB at the caudal pole of round spermatids. During spermatid morphogenesis, Vasa redistributes and forms a second CB that is a ring-like structure surrounding the dense fiber of the flagellum in the midpiece. These structures resemble those described for GP in various species. Thus, Vasa identifies GP and adopts varying structures via dynamic reorganization at different stages of germ cell development. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Gonadal germ cell tumors in children and adolescents

    PubMed Central

    Cecchetto, Giovanni

    2014-01-01

    Pediatric germ cell tumors (GCT) are rare tumors: 80% are benign, 20% malignant (2-3% of all malignant pediatric tumors). The gonadal sites (ovary and testis) account for 40% of cases. Ovarian GCTs: Represent 30% of GCTs and 70% of neoplastic ovarian masses, being the most common ovarian neoplasms in children and teenagers. Benign and immature forms (teratomas) constitute about 80% of all ovarian GCTs, malignant forms represent 20% increasing during adolescence. The most common malignant entity in children is the yolk sac tumors (YST); dysgerminoma is frequent during adolescence and being bilateral in 10% of cases. Presentation is similar in malignant and benign lesions; abdominal pain (70-80%) and lower abdominal mass are common symptoms. Evaluation of alpha-fetoprotein (αFP) or beta subunit of human chorionic gonadotropin (βHCG) is essential to address the nature of the tumors: Their elevation means presence of malignancy. Surgery includes intraoperative staging procedures and requires ovariectomy or ovarosalpingectomy for malignant lesions, but may be conservative in selected benign tumors. Since malignant GCTs are very chemosensitive, primary chemotherapy is recommended in metastatic or locally advanced tumors. Testicular GCT: Represent 10% of pediatric GCT, and about 30% of malignant GCT with two age peaks: Children <3 years may experience mature teratoma and malignant GCTs, represented almost exclusively by YST, while adolescents may also show seminomas or other mixed tumors. The main clinical feature is a painless scrotal mass. Surgery represents the cornerstone of the management of testicular GCTs, with an inguinal approach and a primary high orchidectomy for malignant tumors, while a testis-sparing surgery can be considered for benign lesions. A retroperitoneal lymph node (LN) biopsy may be necessary to define the staging when the involvement of retroperitoneal LN is uncertain at imaging investigations. Conclusion: Patients with gonadal malignant GCTs

  4. Germ cell mutations of the ascidian Ciona intestinalis with TALE nucleases.

    PubMed

    Yoshida, Keita; Treen, Nicholas; Hozumi, Akiko; Sakuma, Tetsushi; Yamamoto, Takashi; Sasakura, Yasunori

    2014-05-01

    Targeted mutagenesis of genes-of-interest, or gene-knockout, is a powerful method to address the functions of genes. Engineered nucleases have enabled this approach in various organisms because of their ease of use. The ascidian Ciona intestinalis is an excellent organism to analyze gene functions by means of genetic technologies. In our previous study, we reported mutagenesis of Ciona somatic cells with TALE nucleases (TALENs) by electroporating expression constructs. In this study, we report germ cell mutagenesis of Ciona by microinjecting mRNAs encoding TALENs. TALEN mRNAs introduced mutations to target genes in both somatic and germ cells. TALEN-mediated mutations in the germ cell genome were inherited by the next generation. We conclude that knockout lines of Ciona that have disrupted target genes can be established through TALEN-mediated germ cell mutagenesis.

  5. Germ-cell deficient (gcd), an insertional mutation manifested as infertility in transgenic mice.

    PubMed Central

    Pellas, T C; Ramachandran, B; Duncan, M; Pan, S S; Marone, M; Chada, K

    1991-01-01

    A genetic analysis is necessary to gain a greater understanding of the complex developmental processes in mammals. Toward this end, an insertional transgenic mouse mutant has been isolated that results in abnormal germ-cell development. This recessive mutation manifests as infertility in both males and females and is specific for the reproductive organs, since all other tissues examined were histologically normal. A developmental analysis of the gonadal tissues demonstrated that the germ cells were specifically depleted as early as day 11.5 of embryonic development, while the various somatic cells were apparently unaffected. Therefore, the mutated locus must play a critical role in the migration/proliferation of primordial germ cells to the genital ridges of developing embryos. In addition, females homozygous for the mutation could potentially be a valuable animal model of a human syndrome, premature ovarian failure. This mutation has been named germ-cell deficient, gcd. Images PMID:1924340

  6. Toward a more precise and informative nomenclature describing fetal and neonatal male germ cells in rodents.

    PubMed

    McCarrey, John R

    2013-08-01

    The germ cell lineages are among the best characterized of all cell lineages in mammals. This characterization includes precise nomenclature that distinguishes among numerous, often subtle, changes in function or morphology as development and differentiation of germ cells proceed to form the gametes. In male rodents, there are at least 41 distinct cell types that occur during progression through the male germ cell lineage that gives rise to spermatozoa. However, there is one period during male germ cell development-that which occurs immediately following the primordial germ cell stage and prior to the spermatogonial stage-for which the system of precise and informative cell type terminology is not adequate. Often, male germ cells during this period are referred to simply as "gonocytes." However, this term is inadequate for multiple reasons, and it is suggested here that nomenclature originally proposed in the 1970s by Hilscher et al., which employs the terms M-, T1-, and T2-prospermatogonia, is preferable. In this Minireview, the history, proper utilization, and advantages of this terminology relative to that of the term gonocytes are described.

  7. Specification and epigenetic programming of the human germ line.

    PubMed

    Tang, Walfred W C; Kobayashi, Toshihiro; Irie, Naoko; Dietmann, Sabine; Surani, M Azim

    2016-10-01

    Primordial germ cells (PGCs), the precursors of sperm and eggs, are established in perigastrulation-stage embryos in mammals. Signals from extra-embryonic tissues induce a unique gene regulatory network in germline-competent cells for PGC specification. This network also initiates comprehensive epigenome resetting, including global DNA demethylation and chromatin reorganization. Mouse germline development has been studied extensively, but the extent to which such knowledge applies to humans was unclear. Here, we review the latest advances in human PGC specification and epigenetic reprogramming. The overall developmental dynamics of human and mouse germline cells appear to be similar, but there are crucial mechanistic differences in PGC specification, reflecting divergence in the regulation of pluripotency and early development.

  8. Measurement of mRNA Poly(A) Tail Lengths in Drosophila Female Germ Cells and Germ-Line Stem Cells.

    PubMed

    Chartier, Aymeric; Joly, Willy; Simonelig, Martine

    2017-01-01

    mRNA regulation by poly(A) tail length variations plays an important role in many developmental processes. Recent advances have shown that, in particular, deadenylation (the shortening of mRNA poly(A) tails) is essential for germ-line stem cell biology in the Drosophila ovary. Therefore, a rapid and accurate method to analyze poly(A) tail lengths of specific mRNAs in this tissue is valuable. Several methods of poly(A) test (PAT) assays have been reported to measure mRNA poly(A) tail lengths in vivo. Here, we describe two of these methods (PAT and ePAT) that we have adapted for Drosophila ovarian germ cells and germ-line stem cells.

  9. Identification and Genetic Analysis of Wunen, a Gene Guiding Drosophila Melanogaster Germ Cell Migration

    PubMed Central

    Zhang, N.; Zhang, J.; Cheng, Y.; Howard, K.

    1996-01-01

    We describe a novel genetic locus, wunen (wun), required for guidance of germ cell migration in early Drosophila development. Loss of wun function does not abolish movement but disrupts the orientation of the motion causing the germ cells to disperse even though their normal target, the somatic gonad, is well formed. We demonstrate that the product of this gene enables a signal to pass from the soma to the germ line and propose that the function of this signal is to selectively stabilize certain cytoplasmic extensions resulting in oriented movement. To characterize this guidance factor, we have mapped wun to within 100 kb of cloned DNA. PMID:8807296

  10. Stem cell research points the way to the cell of origin for intracranial germ cell tumours.

    PubMed

    Tan, Chris; Scotting, Paul J

    2013-01-01

    Germ cell tumours found in the brain (intracranial GCTs) are a very unusual class of tumour for two reasons. First, they include a very diverse range of histological subtypes classified together due to their proposed common cell of origin. Second, this proposed cell of origin, the germ cell progenitor, would not normally be found in the tissue where these tumours arise. This is in contrast to all other primary brain tumours, in which the cell of origin is believed to be a brain cell. Indeed, no other class of primary cancer arises from a cell from a distant organ. This theory for the origins of intracranial GCTs has been in place for many decades, but recent data arising from studies of induced pluripotency for regenerative medicine raise serious questions about this dogma. Here we review the cellular origins of intracranial GCTs in the light of these new data and reanalyse the existing data on the biology of this unusual class of tumours. Together, these considerations lead us to conclude that the evidence now falls in favour of a model in which these tumours arise from the transformation of endogenous brain cells. This theory should inform future studies of the aetiology of these tumours and so lead the way to animal models in which to study their development and potential biological therapeutics. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  11. Germ cells of the centipede Strigamia maritima are specified early in embryonic development.

    PubMed

    Green, Jack E; Akam, Michael

    2014-08-15

    We provide the first systematic description of germ cell development with molecular markers in a myriapod, the centipede Strigamia maritima. By examining the expression of Strigamia vasa and nanos orthologues, we find that the primordial germ cells are specified from at least the blastoderm stage. This is a much earlier embryonic stage than previously described for centipedes, or any other member of the Myriapoda. Using these genes as markers, and taking advantage of the developmental synchrony of Strigamia embryos within single clutches, we are able to track the development of the germ cells throughout embryogenesis. We find that the germ cells accumulate at the blastopore; that the cells do not internalize through the hindgut, but rather through the closing blastopore; and that the cells undergo a long-range migration to the embryonic gonad. This is the first evidence for primordial germ cells displaying these behaviours in any myriapod. The myriapods are a phylogenetically important group in the arthropod radiation for which relatively little developmental data is currently available. Our study provides valuable comparative data that complements the growing number of studies in insects, crustaceans and chelicerates, and is important for the correct reconstruction of ancestral states and a fuller understanding of how germ cell development has evolved in different arthropod lineages.

  12. Germ cell transplantation as a potential biotechnological approach to fish reproduction.

    PubMed

    Lacerda, S M S N; Costa, G M J; Campos-Junior, P H A; Segatelli, T M; Yazawa, R; Takeuchi, Y; Morita, T; Yoshizaki, G; França, L R

    2013-02-01

    Although the use of germ cell transplantation has been relatively well established in mammals, the technique has only been adapted for use in fish after entering the 2000s. During the last decade, several different approaches have been developed for germ cell transplantation in fish using recipients of various ages and life stages, such as blastula-stage embryos, newly hatched larvae and sexually mature specimens. As germ cells can develop into live organisms through maturation and fertilization processes, germ cell transplantation in fish has opened up new avenues of research in reproductive biotechnology and aquaculture. For instance, the use of xenotransplantation in fish has lead to advances in the conservation of endangered species and the production of commercially valuable fish using surrogated recipients. Further, this could also facilitate the engineering of transgenic fish. However, as is the case with mammals, knowledge regarding the basic biology and physiology of germline stem cells in fish remains incomplete, imposing a considerable limitation on the application of germ cell transplantation in fish. Furthering our understanding of germline stem cells would contribute significantly to advances regarding germ cell transplantation in fish.

  13. The PUF binding landscape in metazoan germ cells

    PubMed Central

    Prasad, Aman; Porter, Douglas F.; Kroll-Conner, Peggy L.; Mohanty, Ipsita; Ryan, Anne R.; Crittenden, Sarah L.; Wickens, Marvin; Kimble, Judith

    2016-01-01

    PUF (Pumilio/FBF) proteins are RNA-binding proteins and conserved stem cell regulators. The Caenorhabditis elegans PUF proteins FBF-1 and FBF-2 (collectively FBF) regulate mRNAs in germ cells. Without FBF, adult germlines lose all stem cells. A major gap in our understanding of PUF proteins, including FBF, is a global view of their binding sites in their native context (i.e., their “binding landscape”). To understand the interactions underlying FBF function, we used iCLIP (individual-nucleotide resolution UV crosslinking and immunoprecipitation) to determine binding landscapes of C. elegans FBF-1 and FBF-2 in the germline tissue of intact animals. Multiple iCLIP peak-calling methods were compared to maximize identification of both established FBF binding sites and positive control target mRNAs in our iCLIP data. We discovered that FBF-1 and FBF-2 bind to RNAs through canonical as well as alternate motifs. We also analyzed crosslinking-induced mutations to map binding sites precisely and to identify key nucleotides that may be critical for FBF–RNA interactions. FBF-1 and FBF-2 can bind sites in the 5′UTR, coding region, or 3′UTR, but have a strong bias for the 3′ end of transcripts. FBF-1 and FBF-2 have strongly overlapping target profiles, including mRNAs and noncoding RNAs. From a statistically robust list of 1404 common FBF targets, 847 were previously unknown, 154 were related to cell cycle regulation, three were lincRNAs, and 335 were shared with the human PUF protein PUM2. PMID:27165521

  14. Humanin protects against chemotherapy-induced stage-specific male germ cell apoptosis in rats*

    PubMed Central

    Lue, Y.; Doumit, T.; Jia, Y.; Atienza, V.; Liu, P. Y.; Swerdloff, R. S.; Wang, C.

    2016-01-01

    SUMMARY Humanin (HN) has cytoprotective action on male germ cells after testicular stress induced by heat and hormonal deprivation. To examine whether HN has protective effects on chemotherapy-induced male germ cell apoptosis, we treated four groups of adult rats with (i) vehicle (control), (ii) HN, (iii) cyclophosphamide (CP); or (iv) HN+CP. To investigate whether the protective effects of HN on germ cells require the presence of Leydig cells, another four groups of rats were pre-treated with ethane dimethanesulfonate (EDS), a Leydig cell toxicant, to eliminate Leydig cells. After 3 days, when Leydig cells were depleted by EDS, we administered: (i) vehicle, (ii) HN, (iii) CP; or (iv) HN+CP to rats. All rats were killed 12 h after the injection of HN and/or CP. Germ cell apoptosis was detected by TUNEL assay and quantified by numerical count. Compared with control and HN (alone), CP significantly increased germ cell apoptosis; HN +CP significantly reduced CP-induced apoptosis at early (I–VI) and late stages (IX–XIV) but not at middle stages (VII–VIII) of the seminiferous epithelial cycle. Pre-treatment with EDS markedly suppressed serum and intratesticular testosterone (T) levels, and significantly increased germ cell apoptosis at the middle (VII–VIII) stages. CP did not further increase germ cell apoptosis in the EDS-pre-treated rats. HN significantly attenuated germ cell apoptosis at the middle stages in EDS pre-treated rats. To investigate whether HN has any direct effects on Leydig cell function, adult Leydig cells were isolated and treated with ketoconazole (KTZ) to block testosterone synthesis. HN was not effective in preventing the reduction of T production by KTZ in vitro. We conclude that HN decreases CP and/or EDS-induced germ cell apoptosis in a stage-specific fashion. HN acts directly on germ cells to protect against EDS-induced apoptosis in the absence of Leydig cells and intratesticular testosterone levels are very low. PMID:25891800

  15. Management of primary germ cell tumors of the mediastinum.

    PubMed

    Economou, J S; Trump, D L; Holmes, E C; Eggleston, J E

    1982-05-01

    Twenty-eight patients with primary malignant germ cell tumors (GCT) of the mediastinum were treated at the University of California at Los Angeles and The Johns Hopkins Hospital in the past 30 years. Of 11 patients with pure seminomas, nine (82%) are free of disease from 6 months to 15 years following therapy. The primary treatment modality in these patients was mediastinal radiation; one patient with metastatic disease had a complete remission and prolonged survival following combination chemotherapy. Seventeen patients had GCT with nonseminomatous elements. Only three (18%) are alive and free of disease. One patient treated only surgically is alive at 15 years and two patients treated with combination chemotherapy and operation are alive and free of disease at 6 months and 3 years. When analyzed by a Kaplan-Meier actuarial survival estimate, patients with nonseminomatous GCT who were treated with cisplatin-bleomycin-based chemotherapy had a median survival of 14.0 months whereas those treated with chemotherapy regimens not employing these agents had a median survival of 4.0 months (generalized Wilcoxon test, p = 0.0495). Patients with pure seminomas are effectively treated with radiation therapy. Patients with nonseminomatous tumors have a much poorer prognosis and deserve aggressive multimodality therapy with cisplatin-bleomycin-based chemotherapy.

  16. Inguinal lymph node metastases from germ cell testicular tumors.

    PubMed

    Klein, F A; Whitmore, W F; Sogani, P C; Batata, M; Fisher, H; Herr, H W

    1984-03-01

    Between 1948 and 1982, 22 patients were seen with metastasis to the inguinal nodes from testicular germ cell tumors: 8 had a history of unilateral or bilateral orchiopexy with or without herniorrhaphy, 4 had nonsurgically corrected or uncorrected cryptorchidism, 9 had a history of herniorrhaphy, hydrocelectomy or transscrotal orchiectomy and 1 had no history of scrotal, iliac or inguinal surgery, or of tunica vaginalis or scrotal wall involvement by tumor. The histological type was pure seminoma in 5 patients, embryonal carcinoma in 7 and mixed tumor in 10. Treatment was individualized for tumor type and mode of presentation, and varied during the years according to the modalities available. At the time of this report 8 of 22 patients (36 per cent) are alive without evidence of disease from 2 to 29.5 years, 3 (16 per cent) have died without evidence of disease 10 to 17 years after treatment, 10 (45 per cent) have died of metastases 10 months to 6 years after treatment and 1 has been lost to followup. The over-all incidence of groin metastases from testicular carcinoma is low, even with a history of scrotal or inguinal surgery.

  17. Familial testicular germ cell tumor: no associated syndromic pattern identified

    PubMed Central

    2014-01-01

    Background Testicular germ cell tumor (TGCT) is the most common malignancy in young men. Familial clustering, epidemiologic evidence of increased risk with family or personal history, and the association of TGCT with genitourinary (GU) tract anomalies have suggested an underlying genetic predisposition. Linkage data have not identified a rare, highly-penetrant, single gene in familial TGCT (FTGCT) cases. Based on its association with congenital GU tract anomalies and suggestions that there is an intrauterine origin to TGCT, we hypothesized the existence of unrecognized dysmorphic features in FTGCT. Methods We evaluated 38 FTGCT individuals and 41 first-degree relatives from 22 multiple-case families with detailed dysmorphology examinations, physician-based medical history and physical examination, laboratory testing, and genitourinary imaging studies. Results The prevalence of major abnormalities and minor variants did not significantly differ between either FTGCT individuals or their first-degree relatives when compared with normal population controls, except for tall stature, macrocephaly, flat midface, and retro-/micrognathia. However, these four traits were not manifest as a constellation of features in any one individual or family. We did detect an excess prevalence of the genitourinary anomalies cryptorchidism and congenital inguinal hernia in our population, as previously described in sporadic TGCT, but no congenital renal, retroperitoneal or mediastinal anomalies were detected. Conclusions Overall, our study did not identify a constellation of dysmorphic features in FTGCT individuals, which is consistent with results of genetic studies suggesting that multiple low-penetrance genes are likely responsible for FTGCT susceptibility. PMID:24559313

  18. Activation of the germ-cell potential of human bone marrow-derived cells by a chemical carcinogen.

    PubMed

    Liu, Chunfang; Ma, Zhan; Xu, Songtao; Hou, Jun; Hu, Yao; Yu, Yinglu; Liu, Ruilai; Chen, Zhihong; Lu, Yuan

    2014-07-07

    Embryonic/germ cell traits are common in malignant tumors and are thought to be involved in malignant tumor behaviors. The reasons why tumors show strong embryonic/germline traits (displaced germ cells or gametogenic programming reactivation) are controversial. Here, we show that a chemical carcinogen, 3-methyl-cholanthrene (3-MCA), can trigger the germ-cell potential of human bone marrow-derived cells (hBMDCs). 3-MCA promoted the generation of germ cell-like cells from induced hBMDCs that had undergone malignant transformation, whereas similar results were not observed in the parallel hBMDC culture at the same time point. The malignant transformed hBMDCs spontaneously and more efficiently generated into germ cell-like cells even at the single-cell level. The germ cell-like cells from induced hBMDCs were similar to natural germ cells in many aspects, including morphology, gene expression, proliferation, migration, further development, and teratocarcinoma formation. Therefore, our results demonstrate that a chemical carcinogen can reactivate the germline phenotypes of human somatic tissue-derived cells, which might provide a novel idea to tumor biology and therapy.

  19. TAp73 is essential for germ cell adhesion and maturation in testis

    PubMed Central

    Holembowski, Lena; Kramer, Daniela; Riedel, Dietmar; Sordella, Raffaella; Nemajerova, Alice; Dobbelstein, Matthias

    2014-01-01

    A core evolutionary function of the p53 family is to protect the genomic integrity of gametes. However, the role of p73 in the male germ line is unknown. Here, we reveal that TAp73 unexpectedly functions as an adhesion and maturation factor of the seminiferous epithelium orchestrating spermiogenesis. TAp73 knockout (TAp73KO) and p73KO mice, but not ΔNp73KO mice, display a “near-empty seminiferous tubule” phenotype due to massive premature loss of immature germ cells. The cellular basis of this phenotype is defective cell–cell adhesions of developing germ cells to Sertoli nurse cells, with likely secondary degeneration of Sertoli cells, including the blood–testis barrier, which leads to disruption of the adhesive integrity and maturation of the germ epithelium. At the molecular level, TAp73, which is produced in germ cells, controls a coordinated transcriptional program of adhesion- and migration-related proteins including peptidase inhibitors, proteases, receptors, and integrins required for germ–Sertoli cell adhesion and dynamic junctional restructuring. Thus, we propose the testis as a unique organ with strict division of labor among all family members: p63 and p53 safeguard germ line fidelity, whereas TAp73 ensures fertility by enabling sperm maturation. PMID:24662569

  20. The biology of germ cell tumors in disorders of sex development.

    PubMed

    Hersmus, Remko; van Bever, Yolande; Wolffenbuttel, Katja P; Biermann, Katharina; Cools, Martine; Looijenga, Leendert H J

    2017-02-01

    Development of a malignant germ cell tumor, i.e., germ cell cancer (GCC) in individuals with disorders of sex development (DSD) depends on a number of (epi-)genetic factors related to early gonadal- and germ cell development, possibly related to genetic susceptibility. Fetal development of germ cells is orchestrated by strict processes involving specification, migration and the development of a proper gonadal niche. In this review we will discuss the early (epi-)genetic events in normal and aberrant germ cell and gonadal development. Focus will be on the formation of the precursor lesions of GCC in individuals who have DSD. In our view, expression of the different embryonic markers in, and epigenetic profile of the precursor lesions reflects the developmental stage in which these cells are blocked in their maturation. Therefore, these are not a primary pathogenetic driving force. Progression later in life towards a full blown cancer likely depends on additional factors such as a changed endocrine environment in a susceptible individual. Genetic susceptibility is, as evidenced by the presence of specific risk genetic variants (SNPs) in patients with a testicular GCC, related to genes involved in early germ cell and gonadal development.

  1. Management of germ cell tumors with somatic type malignancy: pathological features, prognostic factors and survival outcomes.

    PubMed

    Rice, Kevin R; Magers, Martin J; Beck, Stephen D W; Cary, K Clint; Einhorn, Lawrence H; Ulbright, Thomas M; Foster, Richard S

    2014-11-01

    Germ cell tumors with somatic type malignancy are rare, occurring in approximately 2.7% to 8.6% of germ cell tumor cases. Prognostic factors and optimal management remain poorly defined. The Indiana University testis cancer database was queried from 1979 to 2011 for patients demonstrating germ cell tumor with somatic type malignancy at orchiectomy or subsequent resection. Patients with transformation to primitive neuroectodermal tumor only were excluded from study due to distinct management. Chart review, pathological review and survival analysis were performed. A total of 121 patients met the study inclusion criteria. The most common somatic type malignancy histologies were sarcoma (59), carcinoma (31) and sarcomatoid yolk sac tumor (17). Of these patients 32 demonstrated somatic type malignancy at germ cell tumor diagnosis. For those with delayed identification, median time from germ cell tumor to somatic type malignancy diagnosis was 33 months. This interval was longest for carcinomas (108 months). At a median followup of 71 months, 5-year cancer specific survival was 64%. Predictors of poorer cancer specific survival included somatic type malignancy diagnosed at late relapse (p = 0.017), referral to Indiana University for reoperative retroperitoneal lymph node dissection (p = 0.026) and grade (p = 0.026). None of these factors maintained prognostic significance on multivariate analysis. Somatic type malignancy histology subtype, stage, risk category and number of resections were not predictive of cancer specific survival. Germ cell tumor with somatic type malignancy is associated with poorer cancer specific survival than traditional germ cell tumor. Established prognostic factors for germ cell tumor lose predictive value in the setting of somatic type malignancy. Aggressive and serial resections are often necessary to optimize cancer specific survival. Tumor grade is an important prognostic factor in sarcomas and sarcomatoid yolk sac tumors. Copyright

  2. Unusual liver locations of growing teratoma syndrome in ovarian malignant germ cell tumors.

    PubMed

    Lorusso, Domenica; Malaguti, Paola; Trivellizzi, Ilaria Nausica; Scambia, Giovanni

    2011-01-01

    ► Growing teratoma syndrome (GTS) with unusual liver locations are described after fertility preserving surgery and chemotherapy treatment for mixed malignant ovarian germ cell tumors (MGCT). ► It's a rare syndrome of mixed malignant ovarian germ cell tumors and in both cases enlarged and growing liver masses appeared during cisplatin-etoposide-bleomicin (BEP) chemotherapy. ► Radiological exams (CT scan and MRI) were suggestive for secondary metastasis and serum markers became negative during chemotherapy.

  3. Uncoupling of pathways that promote postmitotic life span and apoptosis from replicative immortality of Caenorhabditis elegans germ cells.

    PubMed

    Ahmed, Shawn

    2006-12-01

    A dichotomy exists between germ and somatic cells in most organisms, such that somatic cell lineages proliferate for a single generation, whereas the germ cell lineage has the capacity to proliferate from one generation to the next, indefinitely. Several theories have been proposed to explain the unlimited replicative life span of germ cells, including the elimination of damaged germ cells by apoptosis or expression of high levels of gene products that prevent aging in somatic cells. These theories were tested in the nematode Caenorhabditis elegans by examining the consequences of eliminating either apoptosis or the daf-16, daf-18 or sir-2.1 genes that promote longevity of postmitotic somatic cells. However, germ cells of strains deficient for these activities displayed an unlimited proliferative capacity. Thus, C. elegans germ cells retain their youthful character via alternative pathways that prevent or eliminate damage that accumulates as a consequence of cell proliferation.

  4. RNF17, a component of the mammalian germ cell nuage, is essential for spermiogenesis.

    PubMed

    Pan, Jieyan; Goodheart, Mary; Chuma, Shinichiro; Nakatsuji, Norio; Page, David C; Wang, P Jeremy

    2005-09-01

    Nuages are found in the germ cells of diverse organisms. However, nuages in postnatal male germ cells of mice are poorly studied. Previously, we cloned a germ cell-specific gene named Rnf17, which encodes a protein containing both a RING finger and tudor domains. Here, we report that RNF17 is a component of a novel nuage in male germ cells--the RNF17 granule, which is an electron-dense non-membrane bound spherical organelle with a diameter of 0.5 mum. RNF17 granules are prominent in late pachytene and diplotene spermatocytes, and in elongating spermatids. RNF17 granules are distinguishable from other known nuages, such as chromatoid bodies. RNF17 is able to form dimers or polymers both in vitro and in vivo, indicating that it may play a role in the assembly of RNF17 granules. Rnf17-deficient male mice were sterile and exhibited a complete arrest in round spermatids, demonstrating that Rnf17 encodes a novel key regulator of spermiogenesis. Rnf17-null round spermatids advanced to step 4 but failed to produce sperm. These results have shown that RNF17 is a component of a novel germ cell nuage and is required for differentiation of male germ cells.

  5. DNA methylation and chromatin accessibility profiling of mouse and human fetal germ cells

    PubMed Central

    Guo, Hongshan; Hu, Boqiang; Yan, Liying; Yong, Jun; Wu, Yan; Gao, Yun; Guo, Fan; Hou, Yu; Fan, Xiaoying; Dong, Ji; Wang, Xiaoye; Zhu, Xiaohui; Yan, Jie; Wei, Yuan; Jin, Hongyan; Zhang, Wenxin; Wen, Lu; Tang, Fuchou; Qiao, Jie

    2017-01-01

    Chromatin remodeling is important for the epigenetic reprogramming of human primordial germ cells. However, the comprehensive chromatin state has not yet been analyzed for human fetal germ cells (FGCs). Here we use nucleosome occupancy and methylation sequencing method to analyze both the genome-wide chromatin accessibility and DNA methylome at a series of crucial time points during fetal germ cell development in both human and mouse. We find 116 887 and 137 557 nucleosome-depleted regions (NDRs) in human and mouse FGCs, covering a large set of germline-specific and highly dynamic regulatory genomic elements, such as enhancers. Moreover, we find that the distal NDRs are enriched specifically for binding motifs of the pluripotency and germ cell master regulators such as NANOG, SOX17, AP2γ and OCT4 in human FGCs, indicating the existence of a delicate regulatory balance between pluripotency-related genes and germ cell-specific genes in human FGCs, and the functional significance of these genes for germ cell development in vivo. Our work offers a comprehensive and high-resolution roadmap for dissecting chromatin state transition dynamics during the epigenomic reprogramming of human and mouse FGCs. PMID:27824029

  6. Dearth and Delayed Maturation of Testicular Germ Cells in Fanconi Anemia E Mutant Male Mice

    PubMed Central

    Fu, Chun; Begum, Khurshida; Jordan, Philip W.; He, Yan; Overbeek, Paul A.

    2016-01-01

    After using a self-inactivating lentivirus for non-targeted insertional mutagenesis in mice, we identified a transgenic family with a recessive mutation that resulted in reduced fertility in homozygous transgenic mice. The lentiviral integration site was amplified by inverse PCR. Sequencing revealed that integration had occurred in intron 8 of the mouse Fance gene, which encodes the Fanconi anemia E (Fance) protein. Fanconi anemia (FA) proteins play pivotal roles in cellular responses to DNA damage and Fance acts as a molecular bridge between the FA core complex and Fancd2. To investigate the reduced fertility in the mutant males, we analyzed postnatal development of testicular germ cells. At one week after birth, most tubules in the mutant testes contained few or no germ cells. Over the next 2–3 weeks, germ cells accumulated in a limited number of tubules, so that some tubules contained germ cells around the full periphery of the tubule. Once sufficient numbers of germ cells had accumulated, they began to undergo the later stages of spermatogenesis. Immunoassays revealed that the Fancd2 protein accumulated around the periphery of the nucleus in normal developing spermatocytes, but we did not detect a similar localization of Fancd2 in the Fance mutant testes. Our assays indicate that although Fance mutant males are germ cell deficient at birth, the extant germ cells can proliferate and, if they reach a threshold density, can differentiate into mature sperm. Analogous to previous studies of FA genes in mice, our results show that the Fance protein plays an important, but not absolutely essential, role in the initial developmental expansion of the male germ line. PMID:27486799

  7. Dearth and Delayed Maturation of Testicular Germ Cells in Fanconi Anemia E Mutant Male Mice.

    PubMed

    Fu, Chun; Begum, Khurshida; Jordan, Philip W; He, Yan; Overbeek, Paul A

    2016-01-01

    After using a self-inactivating lentivirus for non-targeted insertional mutagenesis in mice, we identified a transgenic family with a recessive mutation that resulted in reduced fertility in homozygous transgenic mice. The lentiviral integration site was amplified by inverse PCR. Sequencing revealed that integration had occurred in intron 8 of the mouse Fance gene, which encodes the Fanconi anemia E (Fance) protein. Fanconi anemia (FA) proteins play pivotal roles in cellular responses to DNA damage and Fance acts as a molecular bridge between the FA core complex and Fancd2. To investigate the reduced fertility in the mutant males, we analyzed postnatal development of testicular germ cells. At one week after birth, most tubules in the mutant testes contained few or no germ cells. Over the next 2-3 weeks, germ cells accumulated in a limited number of tubules, so that some tubules contained germ cells around the full periphery of the tubule. Once sufficient numbers of germ cells had accumulated, they began to undergo the later stages of spermatogenesis. Immunoassays revealed that the Fancd2 protein accumulated around the periphery of the nucleus in normal developing spermatocytes, but we did not detect a similar localization of Fancd2 in the Fance mutant testes. Our assays indicate that although Fance mutant males are germ cell deficient at birth, the extant germ cells can proliferate and, if they reach a threshold density, can differentiate into mature sperm. Analogous to previous studies of FA genes in mice, our results show that the Fance protein plays an important, but not absolutely essential, role in the initial developmental expansion of the male germ line.

  8. Germ Cell-Specific Excision of loxP-Flanked Transgenes in Rainbow Trout Oncorhynchus mykiss.

    PubMed

    Katayama, Naoto; Kume, Sachi; Hattori-Ihara, Shoko; Sadaie, Sakiko; Hayashi, Makoto; Yoshizaki, Goro

    2016-04-01

    Cre/loxP-mediated DNA excision in germ cell lineages could contribute substantially to the study of germ cell biology in salmonids, which are emerging as a model species in this field. However, a cell type-specific Cre/loxPsystem has not been successfully developed for any salmonid species. Therefore, we examined the feasibility of Cre/loxP-mediated, germ cell-specific gene excision and transgene activation in rainbow trout. Double-transgenic (wTg) progeny were obtained by mating a transgenic male carryingcrewith a transgenic female carrying thehsc-LRLGgene;crewas driven by rainbow troutvasaregulatory regions and thehsc-LRLGgene was made up of the rainbow troutheat-shock-cognate71promoter, theDsRedgene flanked by twoloxPsites, and theEgfpgene. PCR analysis, fluorescence imaging, and histological analysis revealed that excision of theloxP-flanked sequence and activation ofEgfpoccurred only in germ cells of wTg fish. However, progeny tests revealed that the excision efficiency ofloxP-flanked sequence in germ cells was low (≤3.27%). In contrast, the other wTg fish derived from two differentcre-transgenic males frequently excised theloxP-flanked sequence in germ cells (≤89.25%). Thus, we showed for the first time successful germ cell-specific transgene manipulation via the Cre/loxPsystem in rainbow trout. We anticipate that this technology will be suitable for studies of cell function through cell targeting, cell-linage tracing, and generating cell type-specific conditional gene knockouts and separately for developing sterile rainbow trout in aquaculture. © 2016 by the Society for the Study of Reproduction, Inc.

  9. Endogenous DNA Damage and Risk of Testicular Germ Cell Tumors

    SciTech Connect

    Cook, M B; Sigurdson, A J; Jones, I M; Thomas, C B; Graubard, B I; Korde, L; Greene, M H; McGlynn, K A

    2008-01-18

    Testicular germ cell tumors (TGCT) are comprised of two histologic groups, seminomas and nonseminomas. We postulated that the possible divergent pathogeneses of these histologies may be partially explained by variable endogenous DNA damage. To assess our hypothesis, we conducted a case-case analysis of seminomas and nonseminomas using the alkaline comet assay to quantify single-strand DNA breaks and alkali-labile sites. The Familial Testicular Cancer study and the U.S. Radiologic Technologists cohort provided 112 TGCT cases (51 seminomas & 61 nonseminomas). A lymphoblastoid cell line was cultured for each patient and the alkaline comet assay was used to determine four parameters: tail DNA, tail length, comet distributed moment (CDM) and Olive tail moment (OTM). Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated using logistic regression. Values for tail length, tail DNA, CDM and OTM were modeled as categorical variables using the 50th and 75th percentiles of the seminoma group. Tail DNA was significantly associated with nonseminoma compared to seminoma (OR{sub 50th percentile} = 3.31, 95%CI: 1.00, 10.98; OR{sub 75th percentile} = 3.71, 95%CI: 1.04, 13.20; p for trend=0.039). OTM exhibited similar, albeit statistically non-significant, risk estimates (OR{sub 50th percentile} = 2.27, 95%CI: 0.75, 6.87; OR{sub 75th percentile} = 2.40, 95%CI: 0.75, 7.71; p for trend=0.12) whereas tail length and CDM showed no association. In conclusion, the results for tail DNA and OTM indicate that endogenous DNA damage levels are higher in patients who develop nonseminoma compared with seminoma. This may partly explain the more aggressive biology and younger age-of-onset of this histologic subgroup compared with the relatively less aggressive, later-onset seminoma.

  10. Differentiation of bone marrow-derived stage-specific embryonic antigen 1 positive pluripotent stem cells into male germ cells.

    PubMed

    Shirazi, Reza; Zarnani, Amir Hassan; Soleimani, Masoud; Nayernia, Karim; Ragerdi Kashani, Iraj

    2017-04-01

    Studies published in recent years have changed the outlook on sterility and germ cell development by producing gametes from stem cells. In present study, a novel approach on differentiation of bone marrow-derived stage-specific embryonic antigen 1 positive (SSEA-1(+) ) pluripotent stem cells into male germ cells has been addressed. SSEA-1(+) stem cells were separated from murine bone marrow using magnetic-activated cell sorting (MACS) system and propagated on a feeder layer cells. To evaluate the pluripotency characteristic of the purified cells, they were differentiated toward cells of three germ layers. Later the SSEA-1(+) stem cells were induced to differentiate along male germ cell lineage with retinoic acid. Flowcytometric analysis of SSEA-1(+) stem cells revealed purity of about 62% which increased to 91% after cultivation over feeder cells. Expression of specific transcripts of Oct4, SSEA-1, Nanog, Dppa3, fragilis, Rex-1, SOX-2, and alkaline-phosphatase and immunofluorescence evaluation of Oct4 and SSEA-1 expression showed the differentiation of purified stem cells toward the cells of three germ layers. Differentiation potential of purified cells was positively evidenced by expression markers specific for primordial germ cells, spermatogonial stem cells and spermatogonia including Mvh, fragilis, Dppa3, Stra8, DAZL, Piwil2, β1, and α6-integrins as well as meiotic-specific marker SYCP3. Our results showed that SSEA-1(+) pluripotent stem cells are able to differentiate into male germ cells. The results of the present study are encouraging enough to merit further investigation, provide a new hope for those suffering from infertility and introduce a novel platform for research on germ cell development. © 2016 Wiley Periodicals, Inc.

  11. Survival of glucose phosphate isomerase null somatic cells and germ cells in adult mouse chimaeras.

    PubMed

    Keighren, Margaret A; Flockhart, Jean H; West, John D

    2016-05-15

    The mouse Gpi1 gene encodes the glycolytic enzyme glucose phosphate isomerase. Homozygous Gpi1(-/-) null mouse embryos die but a previous study showed that some homozygous Gpi1(-/-) null cells survived when combined with wild-type cells in fetal chimaeras. One adult female Gpi1(-/-)↔Gpi1(c/c) chimaera with functional Gpi1(-/-) null oocytes was also identified in a preliminary study. The aims were to characterise the survival of Gpi1(-/-) null cells in adult Gpi1(-/-)↔Gpi1(c/c) chimaeras and determine if Gpi1(-/-) null germ cells are functional. Analysis of adult Gpi1(-/-)↔Gpi1(c/c) chimaeras with pigment and a reiterated transgenic lineage marker showed that low numbers of homozygous Gpi1(-/-) null cells could survive in many tissues of adult chimaeras, including oocytes. Breeding experiments confirmed that Gpi1(-/-) null oocytes in one female Gpi1(-/-)↔Gpi1(c/c) chimaera were functional and provided preliminary evidence that one male putative Gpi1(-/-)↔Gpi1(c/c) chimaera produced functional spermatozoa from homozygous Gpi1(-/-) null germ cells. Although the male chimaera was almost certainly Gpi1(-/-)↔Gpi1(c/c), this part of the study is considered preliminary because only blood was typed for GPI. Gpi1(-/-) null germ cells should survive in a chimaeric testis if they are supported by wild-type Sertoli cells. It is also feasible that spermatozoa could bypass a block at GPI, but not blocks at some later steps in glycolysis, by using fructose, rather than glucose, as the substrate for glycolysis. Although chimaera analysis proved inefficient for studying the fate of Gpi1(-/-) null germ cells, it successfully identified functional Gpi1(-/-) null oocytes and revealed that some Gpi1(-/-) null cells could survive in many adult tissues.

  12. Endosulfan induced cell death in Sertoli-germ cells of male Wistar rat follows intrinsic mode of cell death.

    PubMed

    Rastogi, Divya; Narayan, R; Saxena, D K; Chowdhuri, D Kar

    2014-01-01

    Health of germ cells may affect production of quality gametes either due to endogenous or exogenous factors. Pesticides are among the exogenous factors that can enter the organisms through various routes of exposure and also can affect the reproductive system of an organism. E