Clonal gametogenesis is triggered by intrinsic stimuli in the hybrids germ cells but is dependent on sex differentiation

Interspecific hybridization may trigger the transition from sexual reproduction to asexuality, but mechanistic reasons for such a change in a hybrids reproduction are poorly understood. Gametogenesis of many asexual hybrids involves a stage of premeiotic endoreduplication (PMER), when gonial cells duplicate chromosomes and subsequent meiotic divisions involve bivalents between identical copies, leading to production of clonal gametes. Here, we investigated the triggers of PMER and whether its induction is linked to intrinsic stimuli within a hybrids gonial cells or whether it is regulated by the surrounding gonadal tissue. We investigated gametogenesis in the Cobitis taenia hybrid complex, which involves sexually reproducing species (Cobitis elongatoides and C. taenia) as well as their hybrids, where females reproduce clonally via PMER while males are sterile. We transplanted spermatogonial stem cells (SSCs) from C. elongatoides and triploid hybrid males into embryos of sexual species and of asexual hybrid females, respectively, and observed their development in an allospecific gonadal environment. Sexual SSCs underwent regular meiosis and produced normally reduced gametes when transplanted into clonal females. On the other hand, the hybrids SSCs lead to sterility when transplanted into sexual males, but maintained their ability to undergo asexual development (PMER) and production of clonal eggs, when transplanted into sexual females. This suggests that asexual gametogenesis is under complex control when somatic gonadal tissue indirectly affects the execution of asexual development by determining the sexual differentiation of stem cells and once such cells develop to female phenotypes, hybrid germ cells trigger the PMER from their intrinsic signals.

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Morphohistological studies of the gonads of hybrid polyploid loach cobitis from the Lower Dniester

10.53937/icz10.2021.16 ◽

2021 ◽

Author(s):

Nina Fulga ◽

◽

Laurentia Ungureanu ◽

Dumitru Bulat ◽

Denis Bulat ◽

...

Keyword(s):

Germ Cells ◽

Gonadosomatic Index ◽

Spawning Season ◽

Relative Mass ◽

Breeding Period ◽

Water Basin ◽

Asynchronous Development ◽

Hybrid Complex ◽

Cobitis Taenia

In the lower Dniester, polyploid females of the hybrid complex Cobitis taenia are a portion spawning species with asynchronous development of germ cells during the entire breeding period. The spawning season in this water basin begins in the second decade of May and ends in July. In the population, in parallel with females, hermaphrodite individuals are also present, in which the ovary zone is functional, and the testis zone is sterile. A decrease in the relative mass of the gonads of subsequent generations was noted, which leads to a consistent decrease in the value of the gonadosomatic index, in females, before the second and third spawning.

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Faculty Opinions recommendation of Differentiating germ cells can revert into functional stem cells in Drosophila melanogaster ovaries.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1018401.209470 ◽

2004 ◽

Author(s):

Azim Surani

Keyword(s):

Stem Cells ◽

Drosophila Melanogaster ◽

Germ Cells

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Faculty Opinions recommendation of Identification and characterisation of mRif1: a mouse telomere-associated protein highly expressed in germ cells and embryo-derived pluripotent stem cells.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1021738.247671 ◽

2004 ◽

Author(s):

Stephen Jackson

Keyword(s):

Stem Cells ◽

Germ Cells ◽

Pluripotent Stem Cells

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Formative pluripotent stem cells show features of epiblast cells poised for gastrulation

Cell Research ◽

10.1038/s41422-021-00477-x ◽

2021 ◽

Author(s):

Xiaoxiao Wang ◽

Yunlong Xiang ◽

Yang Yu ◽

Ran Wang ◽

Yu Zhang ◽

...

Keyword(s):

Stem Cells ◽

Germ Cells ◽

Pluripotent Stem Cells ◽

Primordial Germ Cells ◽

Embryonic Stem ◽

Large Set ◽

Mouse Escs ◽

Epiblast Stem Cells ◽

Early Gastrula

AbstractThe pluripotency of mammalian early and late epiblast could be recapitulated by naïve embryonic stem cells (ESCs) and primed epiblast stem cells (EpiSCs), respectively. However, these two states of pluripotency may not be sufficient to reflect the full complexity and developmental potency of the epiblast during mammalian early development. Here we report the establishment of self-renewing formative pluripotent stem cells (fPSCs) which manifest features of epiblast cells poised for gastrulation. fPSCs can be established from different mouse ESCs, pre-/early-gastrula epiblasts and induced PSCs. Similar to pre-/early-gastrula epiblasts, fPSCs show the transcriptomic features of formative pluripotency, which are distinct from naïve ESCs and primed EpiSCs. fPSCs show the unique epigenetic states of E6.5 epiblast, including the super-bivalency of a large set of developmental genes. Just like epiblast cells immediately before gastrulation, fPSCs can efficiently differentiate into three germ layers and primordial germ cells (PGCs) in vitro. Thus, fPSCs highlight the feasibility of using PSCs to explore the development of mammalian epiblast.

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Müllerian Inhibiting Substance Is Required for Germ Cell Proliferation during Early Gonadal Differentiation in Medaka (Oryzias latipes)

Endocrinology ◽

10.1210/en.2007-1535 ◽

2007 ◽

Vol 149 (4) ◽

pp. 1813-1819 ◽

Cited By ~ 47

Author(s):

Eri Shiraishi ◽

Norifumi Yoshinaga ◽

Takeshi Miura ◽

Hayato Yokoi ◽

Yuko Wakamatsu ◽

...

Keyword(s):

Cell Proliferation ◽

Germ Cell ◽

Germ Cells ◽

Sex Differentiation ◽

Somatic Cells ◽

Oryzias Latipes ◽

Cell Number ◽

Gonadal Differentiation ◽

Loss Of Function ◽

Germ Cell Proliferation

Müllerian inhibiting substance (MIS) is a glycoprotein belonging to the TGF-β superfamily. In mammals, MIS is responsible for the regression of Müllerian ducts in the male fetus. However, the role of MIS in gonadal sex differentiation of teleost fish, which have no Müllerian ducts, has yet to be clarified. In the present study, we examined the expression pattern of mis and mis type 2 receptor (misr2) mRNAs and the function of MIS signaling in early gonadal differentiation in medaka (teleost, Oryzias latipes). In situ hybridization showed that both mis and misr2 mRNAs were expressed in the somatic cells surrounding the germ cells of both sexes during early sex differentiation. Loss-of-function of either MIS or MIS type II receptor (MISRII) in medaka resulted in suppression of germ cell proliferation during sex differentiation. These results were supported by cell proliferation assay using 5-bromo-2′-deoxyuridine labeling analysis. Treatment of tissue fragments containing germ cells with recombinant eel MIS significantly induced germ cell proliferation in both sexes compared with the untreated control. On the other hand, culture of tissue fragments from the MIS- or MISRII-defective embryos inhibited proliferation of germ cells in both sexes. Moreover, treatment with recombinant eel MIS in the MIS-defective embryos dose-dependently increased germ cell number in both sexes, whereas in the MISRII-defective embryos, it did not permit proliferation of germ cells. These results suggest that in medaka, MIS indirectly stimulates germ cell proliferation through MISRII, expressed in the somatic cells immediately after they reach the gonadal primordium.

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Spontaneous differentiation of germ cells from human embryonic stem cells in vitro

Human Molecular Genetics ◽

10.1093/hmg/ddh088 ◽

2004 ◽

Vol 13 (7) ◽

pp. 727-739 ◽

Cited By ~ 333

Author(s):

A. T. Clark

Keyword(s):

Stem Cells ◽

Embryonic Stem Cells ◽

Human Embryonic Stem Cells ◽

Germ Cells ◽

Embryonic Stem ◽

Spontaneous Differentiation

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The Culture in vitro of Urogenital Organs of Pleurodeles waltlii

Development ◽

10.1242/dev.10.4.465 ◽

1962 ◽

Vol 10 (4) ◽

pp. 465-470

Author(s):

Charles L. Foote ◽

Florence M. Foote

Keyword(s):

Organ Culture ◽

Germ Cells ◽

Culture Medium ◽

Developmental Stages ◽

Rana Catesbeiana ◽

Sex Differentiation ◽

Organ Cultures ◽

Tissue And Organ Culture ◽

Pleurodeles Waltlii

Earlier reports (Foote & Foote, 1958a, b, 1959) describe growth and maintenance in vitro of larval organs, particularly gonads, of Rana catesbeiana and Xenopus laevis. Immature germ cells of both testes and ovaries are well maintained in vitro, especially if the culture medium is supplemented with watersoluble sex-hormonal substances, although germ cells in process of maturation become necrotic. Recently some urogenital organs from the salamander, Pleurodeles waltlii, have been grown in vitro. Tissues and organs from this amphibian might prove to be more suitable for tissue and organ culture investigations than those of Anurans. Animals at three different ages were used in this study: recently hatched larvae, metamorphosing animals, and adults. To determine whether sex differentiation would occur in vitro, trunk portions of young larvae of Pleurodeles waltlii of developmental stages 37–38 (Gallien & Durocher, 1957) were placed in organ cultures.

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