scholarly journals Somatic cell‐derived BMPs induce premature meiosis in male germ cells during the embryonic stage by upregulating Dazl expression

2022 ◽  
Vol 36 (2) ◽  
Author(s):  
Lianjun Zhang ◽  
Yaqiong Li ◽  
Yuqiong Hu ◽  
Min Chen ◽  
Changhuo Cen ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Germ Cells ◽  
Embryonic Stage ◽  
Male Germ Cells

scholarly journals Identification of a candidate c-mos repressor that restricts transcription of germ cell-specific genes.

1995 ◽  
Vol 15 (10) ◽  
pp. 5369-5375 ◽  
Author(s):  
W Xu ◽  
G M Cooper
Keyword(s):  
Germ Cell ◽  
Somatic Cell ◽  
Binding Site ◽  
Germ Cells ◽  
Phosphoglycerate Kinase ◽  
3T3 Cells ◽  
Male Germ Cells ◽  
Nuclear Extracts ◽  
Genes Encoding ◽  
Nih 3T3

The c-mos proto-oncogene is specifically expressed in female and male germ cells. Previous studies identified a negative regulatory element (NRE) upstream of the c-mos promoter that suppresses c-mos transcription in transfected NIH 3T3 cells. In this study, we used gel shift assays to detect proteins in nuclear extracts of NIH 3T3 cells that bind to the c-mos NRE in a sequence-specific manner. One protein was found to bind to a region of the NRE which was shown by site-directed mutagenesis to be required for suppression of c-mos transcription. This factor was present in nuclear extracts of several somatic cell lines and tissues but not in male germ cells in which c-mos is transcribed, suggesting that it is a somatic cell repressor of c-mos transcription. The binding site of the candidate repressor within the c-mos NRE consists of sequences related to putative NREs identified in two other male germ cell-specific genes (encoding protamine 2 and phosphoglycerate kinase 2). The c-mos repressor bound and could be UV cross-linked to these protamine 2 and phosphoglycerate kinase 2 gene sequences as a protein with an apparent molecular mass of approximately 30 kDa. The repressor binding site is also conserved in two other germ cell-specific genes (encoding testis-specific cytochrome c and heat shock-like protein 70), suggesting that the c-mos repressor may be generally involved in suppressing transcription of germ cell-specific genes in somatic cells.

scholarly journals Somatic cell-derived BMPs induce male germ cell meiosis initiation during embryonic stage via regulating Dazl expression

2020 ◽  
Author(s):  
Lianjun Zhang ◽  
Yaqiong Li ◽  
Yuqiong Hu ◽  
Limei Lin ◽  
Jingjing Zhou ◽  
...  
Keyword(s):  
Germ Cell ◽  
Somatic Cell ◽  
Cell Fate ◽  
Germ Cells ◽  
Bmp Signaling ◽  
Embryonic Stage ◽  
Rna Seq ◽  
Cell Transcriptome

AbstractGerm cell fate is believed to be determined by the signaling from sexually differentiated somatic cell. However, the molecular mechanism remains elusive. In this study, ectopic initiation of meiosis in male germ cells was observed during embryonic stage by over-activating CTNNB1 in Sertoli cells. Somatic cell transcriptome and single germ cell RNA-seq analysis indicated that TGF-β signaling was activated after CTNNB1 over-activation. In vitro and in vivo experiments confirmed somatic cell-derived BMPs played crucial roles in germ cell meiosis initiation. Further studies revealed that Dazl was significantly increased in germ cells of CTNNB1 over-activated testes and induced by BMP signaling. DNMT3a and DNA methylation was also reduced in germ cells of CTNNB1 over-activated testes and increased by BMP signaling inhibitor treatment. Taken together, this study demonstrates that germ cell fate could be reprogrammed after sex determination. BMP signaling pathway is involved in germ cell meiosis initiation via up-regulating Dazl expression.

scholarly journals NANOS2 suppresses the cell cycle by repressing mTORC1 activators in embryonic male germ cells

iScience ◽  
2021 ◽  
pp. 102890
Author(s):  
Ryuki Shimada ◽  
Hiroko Koike ◽  
Takamasa Hirano ◽  
Yuzuru Kato ◽  
Yumiko Saga
Keyword(s):  
Cell Cycle ◽  
Germ Cells ◽  
Male Germ Cells

scholarly journals ELECTRON MICROSCOPE STUDIES ON THE DICTYOSOMES AND ACROBLASTS IN THE MALE GERM CELLS OF THE CRICKET

1956 ◽  
Vol 2 (4) ◽  
pp. 123-128 ◽  
Author(s):  
H. W. Beams ◽  
T. N. Tahmisian ◽  
R. L. Devine ◽  
Everett Anderson
Keyword(s):  
Electron Microscope ◽  
Golgi Apparatus ◽  
Electron Micrographs ◽  
Germ Cells ◽  
Light Microscope ◽  
Golgi Body ◽  
Duplex Structure ◽  
Male Germ Cells ◽  
Secondary Spermatocyte ◽  
A Chain

The dictyosome (Golgi body) in the secondary spermatocyte of the cricket appears in electron micrographs as a duplex structure composed of (a) a group of parallel double-membraned lamellae and (b) a group of associated vacuoles arranged along the compact lamellae in a chain-like fashion. This arrangement of ultramicroscopic structure for the dictyosomes is strikingly comparable to that described for the Golgi apparatus of vertebrates. Accordingly, the two are considered homologous structures. Associated with the duplex structure of the dictyosomes is a differentiated region composed of small vacuoles. This is thought to represent the pro-acrosome region described in light microscope preparations. In the spermatid the dictyosomes fuse, giving rise to the acroblast. Like the dictyosomes, the acroblasts are made up of double-membraned lamellae and associated vacuoles. In addition, a differentiated acrosome region is present which, in some preparations, may display the acrosome vacuole and granule. Both the dictyosomes and acroblasts are distinct from mitochondria.

scholarly journals Male germ cells and photoreceptors, both dependent on close cell–cell interactions, degenerate upon ClC-2 Cl− channel disruption

2001 ◽  
Vol 20 (6) ◽  
pp. 1289-1299 ◽  
Author(s):  
Michael R. Bösl ◽  
Valentin Stein ◽  
Christian Hübner ◽  
Anselm A. Zdebik ◽  
Sven-Eric Jordt ◽  
...  
Keyword(s):  
Germ Cells ◽  
Cell Interactions ◽  
Male Germ Cells ◽  
Cl Channel ◽  
Cell Cell

Golgi Bodies in the Male Germ-Cells of Vaginula maculata

Nature ◽  
1953 ◽  
Vol 172 (4380) ◽  
pp. 690-690 ◽  
Author(s):  
JOHN R. BAKER
Keyword(s):  
Germ Cells ◽  
Male Germ Cells ◽  
Golgi Bodies

scholarly journals The 28 + 28 day design is an effective sampling time for analyzing mutant frequencies in rapidly proliferating tissues of MutaMouse animals

2021 ◽  
Vol 95 (3) ◽  
pp. 1103-1116
Author(s):  
Francesco Marchetti ◽  
Gu Zhou ◽  
Danielle LeBlanc ◽  
Paul A. White ◽  
Andrew Williams ◽  
...  
Keyword(s):  
Germ Cells ◽  
False Negative ◽  
Sampling Time ◽  
Male Germ Cells ◽  
Negative Results ◽  
False Negative Results ◽  
Detection Of Mutations ◽  
The Impact ◽  
Sampling Times

AbstractThe Organisation for Economic Co-Operation and Development Test Guideline 488 (TG 488) uses transgenic rodent models to generate in vivo mutagenesis data for regulatory submission. The recommended design in TG 488, 28 consecutive daily exposures with tissue sampling three days later (28 + 3d), is optimized for rapidly proliferating tissues such as bone marrow (BM). A sampling time of 28 days (28 + 28d) is considered more appropriate for slowly proliferating tissues (e.g., liver) and male germ cells. We evaluated the impact of the sampling time on mutant frequencies (MF) in the BM of MutaMouse males exposed for 28 days to benzo[a]pyrene (BaP), procarbazine (PRC), isopropyl methanesulfonate (iPMS), or triethylenemelamine (TEM) in dose–response studies. BM samples were collected + 3d, + 28d, + 42d or + 70d post exposure and MF quantified using the lacZ assay. All chemicals significantly increased MF with maximum fold increases at 28 + 3d of 162.9, 6.6, 4.7 and 2.8 for BaP, PRC, iPMS and TEM, respectively. MF were relatively stable over the time period investigated, although they were significantly increased only at 28 + 3d and 28 + 28d for TEM. Benchmark dose (BMD) modelling generated overlapping BMD confidence intervals among the four sampling times for each chemical. These results demonstrate that the sampling time does not affect the detection of mutations for strong mutagens. However, for mutagens that produce small increases in MF, sampling times greater than 28 days may produce false-negative results. Thus, the 28 + 28d protocol represents a unifying protocol for simultaneously assessing mutations in rapidly and slowly proliferating somatic tissues and male germ cells.

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