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 Genetic control of programmed cell death in the Caenorhabditis elegans hermaphrodite germline

Development ◽  
1999 ◽  
Vol 126 (5) ◽  
pp. 1011-1022 ◽  
Author(s):  
T.L. Gumienny ◽  
E. Lambie ◽  
E. Hartwieg ◽  
H.R. Horvitz ◽  
M.O. Hengartner
Keyword(s):  
Cell Death ◽  
Caenorhabditis Elegans ◽  
Germ Cell ◽  
Somatic Cell ◽  
Cell Fate ◽  
Germ Cells ◽  
Mapk Pathway ◽  
Apoptotic Cell ◽  
C Elegans ◽  
Pathway Activation

Development of the nematode Caenorhabditis elegans is highly reproducible and the fate of every somatic cell has been reported. We describe here a previously uncharacterized cell fate in C. elegans: we show that germ cells, which in hermaphrodites can differentiate into sperm and oocytes, also undergo apoptotic cell death. In adult hermaphrodites, over 300 germ cells die, using the same apoptotic execution machinery (ced-3, ced-4 and ced-9) as the previously described 131 somatic cell deaths. However, this machinery is activated by a distinct pathway, as loss of egl-1 function, which inhibits somatic cell death, does not affect germ cell apoptosis. Germ cell death requires ras/MAPK pathway activation and is used to maintain germline homeostasis. We suggest that apoptosis eliminates excess germ cells that acted as nurse cells to provide cytoplasmic components to maturing oocytes.

scholarly journals Mouse embryo geometry drives formation of robust signaling gradients through receptor localization

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhechun Zhang ◽  
Steven Zwick ◽  
Ethan Loew ◽  
Joshua S. Grimley ◽  
Sharad Ramanathan
Keyword(s):  
Cell Fate ◽  
Mouse Embryo ◽  
Basolateral Membrane ◽  
Embryonic Stem ◽  
Bmp Signaling ◽  
Receptor Localization ◽  
Bmp Receptors ◽  
Early Mouse

Abstract Morphogen signals are essential for cell fate specification during embryogenesis. Some receptors that sense these morphogens are known to localize to only the apical or basolateral membrane of polarized cell lines in vitro. How such localization affects morphogen sensing and patterning in the developing embryo remains unknown. Here, we show that the formation of a robust BMP signaling gradient in the early mouse embryo depends on the restricted, basolateral localization of BMP receptors. The mis-localization of receptors to the apical membrane results in ectopic BMP signaling in the mouse epiblast in vivo. With evidence from mathematical modeling, human embryonic stem cells in vitro, and mouse embryos in vivo, we find that the geometric compartmentalization of BMP receptors and ligands creates a signaling gradient that is buffered against fluctuations. Our results demonstrate the importance of receptor localization and embryo geometry in shaping morphogen signaling during embryogenesis.

scholarly journals Overexpression of Bcl-w in the Testis Disrupts Spermatogenesis: Revelation of a Role of BCL-W in Male Germ Cell Cycle Control

2003 ◽  
Vol 17 (9) ◽  
pp. 1868-1879 ◽  
Author(s):  
Wei Yan ◽  
Jun-Xing Huang ◽  
Anna-Stina Lax ◽  
Lauri Pelliniemi ◽  
Eeva Salminen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Germ Cell ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Cell Cycle Progression ◽  
Cell Cycle Control ◽  
Testicular Development ◽  
Dna Ladder

Abstract To explore physiological roles of BCL-W, a prosurvival member of the BCL-2 protein family, we generated transgenic (TG) mice overexpressing Bcl-w driven by a chicken β-actin promoter. Male Bcl-w TG mice developed normally but were infertile. The adult TG testes displayed disrupted spermatogenesis with various severities ranging from thin seminiferous epithelium containing less germ cells to Sertoli cell-only appearance. No overpopulation of any type of germ cells was observed during testicular development. In contrast, the developing TG testes displayed decreased number of spermatogonia, degeneration, and detachment of spermatocytes and Sertoli cell vacuolization. The proliferative activity of germ cells was significantly reduced during testicular development and spermatogenesis, as determined by in vivo and in vitro 5′-bromo-2′deoxyuridine incorporation assays. Sertoli cells were structurally and functionally normal. The degenerating germ cells were TUNEL-negative and no typical apoptotic DNA ladder was detected. Our data suggest that regulated spatial and temporal expression of BCL-W is required for normal testicular development and spermatogenesis, and overexpression of BCL-W inhibits germ cell cycle entry and/or cell cycle progression leading to disrupted spermatogenesis.

scholarly journals Formation of organotypic testicular organoids in microwell culture†

2019 ◽  
Vol 100 (6) ◽  
pp. 1648-1660 ◽  
Author(s):  
Sadman Sakib ◽  
Aya Uchida ◽  
Paula Valenzuela-Leon ◽  
Yang Yu ◽  
Hanna Valli-Pulaski ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Germ Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Cell Interactions ◽  
Dependent Manner ◽  
Tissue Architecture ◽  
Cell Cell

Abstract Three-dimensional (3D) organoids can serve as an in vitro platform to study cell–cell interactions, tissue development, and toxicology. Development of organoids with tissue architecture similar to testis in vivo has remained a challenge. Here, we present a microwell aggregation approach to establish multicellular 3D testicular organoids from pig, mouse, macaque, and human. The organoids consist of germ cells, Sertoli cells, Leydig cells, and peritubular myoid cells forming a distinct seminiferous epithelium and interstitial compartment separated by a basement membrane. Sertoli cells in the organoids express tight junction proteins claudin 11 and occludin. Germ cells in organoids showed an attenuated response to retinoic acid compared to germ cells in 2D culture indicating that the tissue architecture of the organoid modulates response to retinoic acid similar to in vivo. Germ cells maintaining physiological cell–cell interactions in organoids also had lower levels of autophagy indicating lower levels of cellular stress. When organoids were treated with mono(2-ethylhexyl) phthalate (MEHP), levels of germ cell autophagy increased in a dose-dependent manner, indicating the utility of the organoids for toxicity screening. Ablation of primary cilia on testicular somatic cells inhibited the formation of organoids demonstrating an application to screen for factors affecting testicular morphogenesis. Organoids can be generated from cryopreserved testis cells and preserved by vitrification. Taken together, the testicular organoid system recapitulates the 3D organization of the mammalian testis and provides an in vitro platform for studying germ cell function, testicular development, and drug toxicity in a cellular context representative of the testis in vivo.

scholarly journals Mouse Germ Cell Development in-vivo and in-vitro

2007 ◽  
Vol 2 ◽  
pp. 117727190700200 ◽  
Author(s):  
Deshira Saiti ◽  
Orly Lacham-Kaplan
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Germ Cell ◽  
Germ Cells ◽  
Expression Patterns ◽  
Embryonic Stem ◽  
Cell Lineage ◽  
Initial Population

In mammalian development, primordial germ cells (PGCs) represent the initial population of cells that are committed to the germ cell lineage. PGCs segregate early in development, triggered by signals from the extra-embryonic ectoderm. They are distinguished from surrounding cells by their unique gene expression patterns. Some of the more common genes used to identify them are Blimp1, Oct3/4, Fragilis, Stella, c-Kit, Mvh, Dazl and Gcna1. These genes are involved in regulating their migration and differentiation, and in maintaining the pluripotency of these cells. Recent research has demonstrated the possibility of obtaining PGCs, and subsequently, mature germ cells from a starting population of embryonic stem cells (ESCs) in culture. This phenomenon has been investigated using a variety of methods, and ESC lines of both mouse and human origin. Embryonic stem cells can differentiate into germ cells of both the male and female phenotype and in one case has resulted in the birth of live pups from the fertilization of oocytes with ESC derived sperm. This finding leads to the prospect of using ESC derived germ cells as a treatment for sterility. This review outlines the evolvement of germ cells from ESCs in vitro in relation to in vivo events.

Cell Junction Dynamics in the Testis: Sertoli-Germ Cell Interactions and Male Contraceptive Development

2002 ◽  
Vol 82 (4) ◽  
pp. 825-874 ◽  
Author(s):  
C. Yan Cheng ◽  
Dolores D. Mruk
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Cell Biology ◽  
Cell Communication ◽  
Seminiferous Epithelium ◽  
Cell Junction ◽  
In Vivo Models ◽  
Blood Testis Barrier

Spermatogenesis is an intriguing but complicated biological process. However, many studies since the 1960s have focused either on the hormonal events of the hypothalamus-pituitary-testicular axis or morphological events that take place in the seminiferous epithelium. Recent advances in biochemistry, cell biology, and molecular biology have shifted attention to understanding some of the key events that regulate spermatogenesis, such as germ cell apoptosis, cell cycle regulation, Sertoli-germ cell communication, and junction dynamics. In this review, we discuss the physiology and biology of junction dynamics in the testis, in particular how these events affect interactions of Sertoli and germ cells in the seminiferous epithelium behind the blood-testis barrier. We also discuss how these events regulate the opening and closing of the blood-testis barrier to permit the timely passage of preleptotene and leptotene spermatocytes across the blood-testis barrier. This is physiologically important since developing germ cells must translocate across the blood-testis barrier as well as traverse the seminiferous epithelium during their development. We also discuss several available in vitro and in vivo models that can be used to study Sertoli-germ cell anchoring junctions and Sertoli-Sertoli tight junctions. An in-depth survey in this subject has also identified several potential targets to be tackled to perturb spermatogenesis, which will likely lead to the development of novel male contraceptives.

scholarly journals In vivo and in vitro differentiation of male germ cells in the mouse

Reproduction ◽  
2004 ◽  
Vol 128 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Orly Lacham-Kaplan
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Embryonic Stem ◽  
Embryoid Bodies ◽  
Cellular Interactions ◽  
Germ Cell Differentiation

Primordial germ cells appear in the embryo at about day 7 after coitum. They proliferate and migrate towards the genital ridge. Once there, they undergo differentiation into germ stem cells, known as ‘A spermatogonia’. These cells are the foundation of spermatogenesis. A spermatogonia commit to spermatogenesis, stay undifferentiated or degenerate. The differentiation of primordial germ cells to migratory, postmigratory and germ stem cells is dependent on gene expression and cellular interactions. Some of the genes that play a crucial role in germ cell differentiation are Steel, c-Kit, VASA, DAZL, fragilis, miwi, mili, mil1 and mil2. Their expression is stage specific, therefore allowing solid identification of germ cells at different developmental phases. In addition to the expression of these genes, other markers associated with germ cell development are nonspecific alkaline phosphatase activity, the stage specific embryonic antigen, the transcription factor Oct3/4 and β1- and α6-integrins. Commitment of cells to primordial germ cells and to A spermatogonia is also dependent on induction by the bone morphogenetic protein (BMP)-4. With this knowledge, researchers were able to isolate germ stem cells from embryonic stem cell-derived embryoid bodies, and drive these into gametes either in vivo or in vitro. Although no viable embryos were obtained from these gametes, the prospects are that this goal is not too far from being accomplished.

scholarly journals Single Cell Sequencing Reveals Early PGC-like Intermediates During Mouse Primed to Naïve Transition

2021 ◽  
Author(s):  
Jing Liu ◽  
Shengyong Yu ◽  
Chunhua Zhou ◽  
Jiangping He ◽  
Xingnan Huang ◽  
...  
Keyword(s):  
Germ Cell ◽  
Single Cell ◽  
Cell Fate ◽  
Single Cell Analysis ◽  
Primordial Germ Cell ◽  
Model System ◽  
Cell Analysis ◽  
Rna Seq ◽  
Single Cell Sequencing

Abstract Single cell analysis provides clarity unattainable with bulk approaches. Here we apply single cell RNA-seq to a newly established BMP4 induced mouse primed to naive transition (Bi-PNT) system and show that the reset is not a direct reversal of cell fate but through developmental intermediates. We first show that mEpiSCs bifurcate into c-Kit+ naïve and c-Kit- placenta-like cells, among which, the naive branch undergoes further transition through a primordial germ cell-like cells (PGCLCs) intermediate capable of spermatogenesis in vivo. Indeed, deficiency of Prdm1/Blimp1, the key regulator for PGC specification, blocks the induction of PGCLCs and naïve cells. Instead, Gata2 knockout arrests placenta-like fate, but facilitates the generation of PGCLCs. Our results not only reveal a newly cell fate dynamics between primed and naive states at single-cell resolution, but also provide a model system to explore mechanisms involved in regaining germline competence from primed pluripotency.

scholarly journals Germline sexual fate is determined by the antagonistic action of dmrt1 and foxl3/foxl2 in tilapia

Development ◽  
2021 ◽  
pp. dev.199380
Author(s):  
Shengfei Dai ◽  
Shuangshuang Qi ◽  
Xueyan Wei ◽  
Xingyong Liu ◽  
Yibing Li ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Germ Cell ◽  
Somatic Cell ◽  
Cell Fate ◽  
Germ Cells ◽  
Sex Reversal ◽  
Testicular Development ◽  
Antagonistic Action ◽  
Male And Female ◽  
Fate Decision

Germline sexual fate has long been believed to be determined by the somatic environment, but this idea is challenged by recent studies of foxl3 mutants in medaka. Here we demonstrate that the sexual fate of tilapia germline is determined by the antagonistic interaction of dmrt1 and foxl3, which are transcriptionally repressed in male and female germ cells, respectively. Loss of dmrt1 rescued the germ cell sex reversal in foxl3Δ7/Δ7 XX fish, and loss of foxl3 partially rescued germ cell sex reversal but not somatic cell fate in dmrt1Δ5/Δ5 XY fish. Interestingly, germ cells lost sexual plasticity in dmrt1Δ5/Δ5 XY and foxl3Δ7/Δ7 XX single mutants, as aromatase inhibitor and estrogen treatment failed to rescue the respective phenotypes. However, recovery of germ cell sexual plasticity was observed in dmrt1/foxl3 double mutants. Importantly, mutation of somatic cell specific foxl2 resulted in testicular development in foxl3Δ7/Δ7 or dmrt1Δ5/Δ5 mutants. Our findings demonstrate that sexual plasticity of germ cells relies on the presence of both dmrt1 and foxl3. The existence of dmrt1 and foxl3 allows environmental factors to influence the sex fate decision in vertebrates.

scholarly journals Genetic and structural analysis of the in vivo functional redundancy between murine NANOS2 and NANOS3

Development ◽  
2020 ◽  
pp. dev.191916
Author(s):  
Danelle Wright ◽  
Makoto Kiso ◽  
Yumiko Saga
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Double Knockout ◽  
Germ Cell Differentiation ◽  
Evolutionarily Conserved ◽  
Male Specific

NANOS2 and NANOS3 are evolutionarily conserved RNA-binding proteins involved in murine germ cell development. NANOS3 is required for protection from apoptosis during migration and gonadal colonization in both sexes, whereas NANOS2 is male-specific and required for the male-type differentiation of germ cells. Ectopic NANOS2 rescues the functions of NANOS3, but NANOS3 cannot rescue NANOS2 function even though its expression is up-regulated in Nanos2-null conditions. It is unknown why NANOS3 cannot rescue NANOS2 function and it is unclear whether NANOS3 plays any role in male germ cell differentiation. To address these questions, we made conditional Nanos3/Nanos2 knockout mice and chimeric mice expressing chimeric NANOS proteins. Conditional double knockout of Nanos2 and 3 led to the rapid loss of germ cells, and in vivo and in vitro experiments revealed that DND1 and NANOS2 binding is dependent on the specific NANOS2 zinc finger structure. Moreover, murine NANOS3 failed to bind CNOT1, an interactor of NANOS2 at its N-terminal. Collectively, our study suggests that the inability of NANOS3 to rescue NANOS2 function is due to poor DND1 recruitment and CNOT1 binding.

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