In vitro germ cell differentiation during sex differentiation in a teleost fish

SummaryIn a previous study, we have identified a set of conserved spermatogenic genes whose expression is restricted to testis and ovary and that are developmentally regulated. One of these genes, the transcription factor Mael, has been reported to play an essential role in mouse spermatogenesis. Nevertheless, the role of Mael in mouse oogenesis has not been defined. In order to analyse the role of Mael in mouse oogenesis, the expression of this gene was blocked during early oogenesis in mouse in vitro using RNAi technology. In addition, the role of Mael during differentiation of embryonic stem cells (ESC) into germ cells in vitro was analysed. Results show that downregulation of Mael by a specific short interfering RNA disrupted fetal oocyte growth and differentiation in fetal ovary explants in culture and the expression of several germ-cell markers in ESC during their differentiation. These results suggest that there is an important role for Mael in early oogenesis and during germ-cell differentiation from embryonic stem cells in mouse in vitro.

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Characterization of human oocyte development and the role of mitochondrial activity in in vitro germ cell differentiation

10.17760/d20316319 ◽

2019 ◽

Author(s):

Alisha M. Bothun

Keyword(s):

Cell Differentiation ◽

Germ Cell ◽

Oocyte Development ◽

Human Oocyte ◽

Mitochondrial Activity ◽

Germ Cell Differentiation

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167. MUSASHI FAMILY OF RNA BINDING PROTEINS: CELL CYCLE REGULATORS IN SPERMATOGENESIS

Reproduction Fertility and Development ◽

10.1071/srb10abs167 ◽

2010 ◽

Vol 22 (9) ◽

pp. 85

Author(s):

E. A. McLaughlin ◽

B. A. Fraser ◽

V. Pye ◽

M. Bigland ◽

N. A. Siddall ◽

...

Keyword(s):

Cell Cycle ◽

Cell Differentiation ◽

Germ Cell ◽

Binding Proteins ◽

Rna Binding ◽

Rna Binding Proteins ◽

Translational Repression ◽

Germ Cell Differentiation ◽

Pachytene Spermatocytes

Mammalian meiosis is a tightly regulated process involving specialized cell cycle progression and morphogenetic changes. We have demonstrated that the Musashi family of RNA binding proteins is implicated in the regulation of spermatogonial stem self renewal and germ cell differentiation. Here we describe the novel mechanism by which the Musashi family proteins, Msi1 and Msi2, act to control exit from spermatogonial mitotic amplification and normal entry into meiosis. Gene and protein analysis indicated overlapping Msi1 and Msi2 profiles in enriched populations of isolated germ cells and reciprocal subcellular expression patterns in spermatogonia and pachytene spermatocytes/ round spermatids in testes sections. Recombinant Msi1 protein-RNA pulldown and microarray analysis coupled with in vitro shRNA knockdown studies in spermatogonial culture and subsequent immunoprecipitation and qPCR established that Msi1 targeted Msi2 mRNA for post transcriptional translational repression. Immunoprecipitation of Msi2 target mRNA and subsequent qPCR together with in vitro shRNA knockdown studies inround spermatidculture identified a cell cycle inhibitor protein CDKN1C (p57kip2) as the principal target of Msi2 translational inhibition. Immunolocalisation of CDKN1C protein indicated that expression of this cell cycle regulator coincided with the nuclear import of Msi1 and the appearance of cytoplasmic Msi2 expression in early pachytene spermatocytes. Using a transgenic Msi1 overexpression mouse model in conjunction with quantitative gene and protein expression, we confirmed Msi1 targeting of Msi2 and subsequent Msi2 targeting of CDKN1C for translational repression in vivo. Ectopic overexpression of Msi1 in germ cellsinduces substantial Msi2 downregulation and aberrant CDKN1C expression, resulting in abnormal spermatogenic differentiation, germ cell apoptosis/arrest and sterility. In conclusion, our results indicate a sophisticated molecular switch encompassing cell cycle protein regulation by Musashi family proteins, is required for normal exit from mitotic division, entry into meiosis and post meiotic germ cell differentiation.

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Hormones and the differentiation of type A spermatogonia in mouse cryptorchid testes incubated in vitro

Journal of Endocrinology ◽

10.1677/joe.0.0940043 ◽

1982 ◽

Vol 94 (1) ◽

pp. 43-NP ◽

Cited By ~ 20

Author(s):

Tatsuji Haneji ◽

Yoshitake Nishimune

Keyword(s):

Cell Differentiation ◽

Germ Cell ◽

Cyclic Adenosine Monophosphate ◽

Type A ◽

Adenosine Monophosphate ◽

Testicular Germ Cell ◽

Adult Mice ◽

Germ Cell Differentiation ◽

Type A Spermatogonia

In order to study hormonal effects on testicular germ cell differentiation, especially on type A spermatogonia, artificially induced cryptorchid testes of adult mice were cultured in a medium containing testosterone, dihydrotestosterone, tri-iodothyronine, dibutyryl 3′: 5′ cyclic adenosine monophosphate, human chorionic gonadotrophin, LH, FSH, insulin and transferrin. These substances, with the exception of FSH, showed no stimulatory effect on the differentiation of type A spermatogonia. However, FSH activated cell division in type A spermatogonia and stimulated them to differentiate, while LH showed neither the promotion of differentiation nor a synergistic effect on FSH-mediated germ cell differentiation.

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Critical role of Emx2 in the pluripotency – differentiation transition in male gonocytes via regulation of FGF9/NODAL pathway

Reproduction ◽

10.1530/rep-16-0022 ◽

2016 ◽

Vol 151 (6) ◽

pp. 673-681 ◽

Cited By ~ 7

Author(s):

Ma Tian-Zhong ◽

Chen Bi ◽

Zhang Ying ◽

Jing Xia ◽

Peng Cai-Ling ◽

...

Keyword(s):

Cell Differentiation ◽

Mouse Model ◽

Germ Cell ◽

Germ Cells ◽

Critical Role ◽

Genital Ridge ◽

Germ Cell Differentiation ◽

Pluripotency Markers

Abstract Emx2 deletion impairs the growth and maintenance of the genital ridge. However, its role in subsequent germ cell differentiation during embryonic stages is unknown. Using a tamoxifen-inducible Cre-loxP mouse model (Emx2flox/flox, Cre-ERTM, hereafter called as Emx2 knockdown), we showed that germ cell differentiation was impaired in Emx2-knockdown testes. Representative characteristics of male germ cell differentiation, including a reduced ability to form embryonic germ (EG) cell colonies in vitro, down-regulation of pluripotency markers and G1/G0 arrest, did not occur in Emx2-knockdown testes. Furthermore, FGF9 and NODAL signalling occurred at abnormally high levels in Emx2-knockdown testes. Both blocking FGF9 signalling with SU5402 and inhibiting NODAL signalling with SB431542 allowed germ cells from Emx2-knockdown testes to differentiate in vitro. Therefore, EMX2 in somatic cells is required to trigger germ cell differentiation in XY foetuses, posterior to its previously reported role in the growth and maintenance of the genital ridge.

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