scholarly journals A transgenic DND1GFP fusion allele reports in vivo expression and RNA binding targets in undifferentiated mouse germ cells

Author(s):  
Victor A Ruthig ◽  
Tetsuhiro Yokonishi ◽  
Matthew B Friedersdorf ◽  
Sofia Batchvarova ◽  
Josiah Hardy ◽  
...  

Abstract In vertebrates, the RNA binding protein (RBP) Dead End 1 (DND1) is essential for primordial germ cell (PGC) survival and maintenance of cell identity. In multiple species, Dnd1 loss or mutation leads to severe PGC loss soon after specification or, in some species, germ cell transformation to somatic lineages. Our investigations into the role of DND1 in PGC specification and differentiation have been limited by the absence of an available antibody. To address this problem, we used CRISPR/Cas9 gene editing to establish a transgenic mouse line carrying a DND1GFP fusion allele. We present imaging analysis of DND1GFP expression showing that DND1GFP expression is heterogeneous among male germ cells (MGCs) and female germ cells (FGCs). DND1GFP was detected in MGCs throughout fetal life but lost from FGCs at meiotic entry. In postnatal and adult testes, DND1GFP expression correlated with classic markers for the pre-meiotic spermatogonial population. Utilizing the GFP-tag for RNA immunoprecipitation (RIP) analysis in MGCs validated this transgenic as a tool for identifying in vivo transcript targets of DND1. The DND1GFP mouse line is a novel tool for isolation and analysis of embryonic and fetal germ cells, and the spermatogonial population of the postnatal and adult testis.

Development ◽  
2020 ◽  
pp. dev.191916
Author(s):  
Danelle Wright ◽  
Makoto Kiso ◽  
Yumiko Saga

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.


Reproduction ◽  
2003 ◽  
pp. 589-597 ◽  
Author(s):  
PT Saunders ◽  
JM Turner ◽  
M Ruggiu ◽  
M Taggart ◽  
PS Burgoyne ◽  
...  

The autosomal gene DAZL is a member of a family of genes (DAZL, DAZ, BOULE), all of which contain a consensus RNA binding domain and are expressed in germ cells. Adult male and female mice null for Dazl lack gametes. In order to define more precisely the developmental stages in germ cells that require Dazl expression, the patterns of germ cell loss in immature male and female wild-type (+/+, WT) and Dazl -/- (DazlKO) mice were analysed. In females, loss of germ cells occurred during fetal life and was coincident with progression of cells through meiotic prophase. In males, testes were recovered from WT and DazlKO males obtained before and during the first wave of spermatogenesis (days 2-19). Mitotically active germ cells were present up to and including day 19. Functional differentiation of spermatogonia associated with detection of c-kit positive cells did not depend upon expression of Dazl. RBMY-positive cells (A, intermediate, B spermatogonia, zygotene and preleptotene spermatocytes) were reduced in DazlKO compared with WT testes. Staining of cell squashes from day 19 testes with anti-gamma-H2AX and anti-SCP3 antibodies showed that germ cells from DazlKO males were unable to progress beyond the leptotene stage of meiotic prophase I. It was concluded that in the absence of Dazl, germ cells can complete mitosis, and embark on functional differentiation but that, in both sexes, progression through meiotic prophase requires this RNA binding protein.


Reproduction ◽  
2003 ◽  
pp. 519-526 ◽  
Author(s):  
T Mayanagi ◽  
K Ito ◽  
J Takahashi

Primordial germ cells differentiate into germ cells and have the ability to reacquire totipotency. Mouse primordial germ cells are identified by alkaline phosphatase staining of the extraembryonic mesoderm, and they proliferate and migrate to reach the genital ridges. Mouse primordial germ cells have never been maintained in culture exclusively for longer than a week without differentiation or dedifferentiation. Moreover, primordial germ cells have not been proliferated with urogenital complexes in vitro, because gonad culture has never been successful. It was thought that primordial germ cells could proliferate in a culture of urogenital complex under modified medium conditions resembling those in vivo; however, organ culture of mouse gonad has been performed with fetal calf serum or equine serum, and those sera produce conditions different from those in vivo. Therefore, mouse urogenital complexes were cultured in media containing rodent sera. As a result, it was possible to proliferate primordial germ cell-like cells outside gonads, and these cells very closely resembled primordial germ cells. In addition, motile primordial germ cell-like cells could be obtained. The ability to maintain primordial germ cell-like cells in culture by this intra-species culture method is important in the study of gametogenesis. Furthermore, this method is useful as a source of stem cells such as embryonic germ cells.


Author(s):  
Hiroshi Ohta ◽  
Yukihiro Yabuta ◽  
Kazuki Kurimoto ◽  
Tomonori Nakamura ◽  
Yusuke Murase ◽  
...  

Abstract Primordial germ cells (PGCs) are the founding population of the germ cell lineage that undergo a multistep process to generate spermatozoa or oocytes. Establishing an appropriate culture system for PGCs is a key challenge in reproductive biology. By a chemical screening using mouse PGC-like cells (mPGCLCs), which were induced from mouse embryonic stem cells, we reported previously that forskolin and rolipram synergistically enhanced the proliferation/survival of mPGCLCs with an average expansion rate of ~20-fold. In the present study, we evaluated other chemicals or cytokines to see whether they would improve the current mPGCLC culture system. Among the chemicals and cytokines examined, in the presence of forskolin and rolipram, cyclosporin A (CsA) and fibroblast growth factors (FGFs: FGF2 and FGF10) effectively enhanced the expansion of mPGCLCs in vitro (~50-fold on average). During the expansion by CsA or FGFs, mPGCLCs comprehensively erased their DNA methylation to acquire a profile equivalent to that of gonadal germ cells in vivo, while maintaining their highly motile phenotype as well as their transcriptional properties as sexually uncommitted PGCs. Importantly, these mPGCLCs robustly contributed to spermatogenesis and produced fertile offspring. Furthermore, mouse PGCs (mPGCs) cultured with CsA ex vivo showed transcriptomes and DNA methylomes similar to those of cultured mPGCLCs. The improved culture system for mPGCLCs/mPGCs would be instructive for addressing key questions in PGC biology, including the mechanisms for germ cell migration, epigenetic reprogramming, and sex determination of the germline.


2019 ◽  
Vol 116 (51) ◽  
pp. 25677-25687 ◽  
Author(s):  
Peter K. Nicholls ◽  
Hubert Schorle ◽  
Sahin Naqvi ◽  
Yueh-Chiang Hu ◽  
Yuting Fan ◽  
...  

Mammalian primordial germ cells (PGCs) are induced in the embryonic epiblast, before migrating to the nascent gonads. In fish, frogs, and birds, the germline segregates even earlier, through the action of maternally inherited germ plasm. Across vertebrates, migrating PGCs retain a broad developmental potential, regardless of whether they were induced or maternally segregated. In mammals, this potential is indicated by expression of pluripotency factors, and the ability to generate teratomas and pluripotent cell lines. How the germline loses this developmental potential remains unknown. Our genome-wide analyses of embryonic human and mouse germlines reveal a conserved transcriptional program, initiated in PGCs after gonadal colonization, that differentiates germ cells from their germline precursors and from somatic lineages. Through genetic studies in mice and pigs, we demonstrate that one such gonad-induced factor, the RNA-binding protein DAZL, is necessary in vivo to restrict the developmental potential of the germline; DAZL’s absence prolongs expression of aNanogpluripotency reporter, facilitates derivation of pluripotent cell lines, and causes spontaneous gonadal teratomas. Based on these observations in humans, mice, and pigs, we propose that germ cells are determined after gonadal colonization in mammals. We suggest that germ cell determination was induced late in embryogenesis—after organogenesis has begun—in the common ancestor of all vertebrates, as in modern mammals, where this transition is induced by somatic cells of the gonad. We suggest that failure of this process of germ cell determination likely accounts for the origin of human testis cancer.


2021 ◽  
Author(s):  
Lacy Barton ◽  
Justina Sanny ◽  
Emily P Dawson ◽  
Marcela Nouzova ◽  
Fernando G Noriega ◽  
...  

Germ cells are essential to sexual reproduction. Across the animal kingdom, extracellular isoprenoids, such as retinoic acids (RAs) in vertebrates and juvenile hormones (JHs) in insects, impact the germline lifecycle from meiosis to gametogenesis. Emerging evidence suggests that these bioactive isoprenoids also influence embryonic reproductive development, though the precise functions remain unclear. Here, we investigated the specific molecular pathways by which JHs regulates embryonic germ cell development in Drosophila. With a newly generated in vivo reporter, we find that JH signaling is active in the vicinity of germ cells as they migrate to colonize the somatic gonad. Through a combination of in vivo and in vitro assays, we find that JHs are both necessary and sufficient for primordial germ cell migration through mechanisms independent of canonical nuclear receptor-mediated transcription. These findings reveal that JH is present during Drosophila embryogenesis and that bioactive isoprenoids impact germ cell development earlier than previously appreciated. Interestingly, we find that like JH in Drosophila, RA is sufficient for murine germ cell migration in vitro, suggesting that the impact of bioactive isoprenoids on embryonic germ cell development may be broadly conserved.


Aquaculture ◽  
2021 ◽  
Vol 535 ◽  
pp. 736381
Author(s):  
Geovanna Carla Zacheo Coelho ◽  
Dilberto Ribeiro Arashiro ◽  
Tamiris Disselli ◽  
Matheus Pereira-Santos ◽  
Tatiana María Mira-López ◽  
...  

genesis ◽  
2006 ◽  
Vol 44 (6) ◽  
pp. 277-286 ◽  
Author(s):  
Céline Souilhol ◽  
Sarah Cormier ◽  
Marie Monet ◽  
Sandrine Vandormael-Pournin ◽  
Anne Joutel ◽  
...  

2020 ◽  
Author(s):  
Jiyoung Lee ◽  
Yeonjoo Kim ◽  
Paris Ataliotis ◽  
Hyung-Goo Kim ◽  
Dae-Won Kim ◽  
...  

ABSTRACTMutations of WDR11 are associated with Kallmann syndrome (KS) and congenital hypogonadotrophic hypogonadism (CHH), typically caused by defective functions of gonadotrophin-releasing hormone (GnRH) neurones in the brain. We previously reported that Wdr11 knockout mice show profound infertility with significantly fewer germ cells present in the gonads. To understand the underlying mechanisms mediated by WDR11 in these processes, we investigated the effects of Wdr11 deletion on primordial germ cell (PGC) development. Using live-tracking of PGCs and primary co-cultures of genital ridges (GR), we demonstrated that Wdr11-deficient embryos contained reduced numbers of PGCs which had delayed migration due to significantly decreased proliferation and motility. We found primary cilia-dependent canonical Hedgehog (Hh) signalling was required for proliferation of the somatic mesenchymal cells of GR, while primary cilia-independent non-canonical Hh signalling mediated by Ptch2/Gas1 and downstream effectors Src and Creb was required for PGC proliferation and migration, which was disrupted by the loss of function mutations of WDR11. Therefore, canonical and non-canonical Hh signalling are differentially involved in the development of somatic and germ cell components of the gonads, and WDR11 is required for both of these pathways operating in parallel in GR and PGCs, respectively, during normal PGC development. Our study provides a mechanistic link between the development of GnRH neurones and germ cells mediated by WDR11, which may underlie some cases of KS/CHH and ciliopathies.


2021 ◽  
Author(s):  
Shuiqiao Yuan ◽  
Shenglei Feng ◽  
Jinmei Li ◽  
Hui Wen ◽  
Kuan Liu ◽  
...  

Abstract Coordinated regulation of alternative pre-mRNA splicing is essential for germ cell development. However, the molecular mechanism underlying that control alternative mRNA expression during germ cell development remains poorly understood. Herein, we showed that hnRNPH1, an RNA-binding protein, is highly expressed in the reproductive system and localized in the chromosomes of meiotic cells but excluded from the XY body in pachytene spermatocytes and recruits the splicing regulators PTBP2 and SRSF3 and cooperatively regulates the alternative splicing of the critical genes that are required for spermatogenesis. Conditional knockout Hnrnph1 in spermatogenic cells caused many abnormal splicing events that affect genes related to meiosis and communication between germ cells and Sertoli cells, characterized by asynapsis of chromosomes and impairment of germ-Sertoli communications, ultimately leading to male sterility. We further showed that hnRNPH1 could directly bind to SPO11 and recruit the splicing regulators PTBP2 and SRSF3 to regulate the alternative splicing of the target genes cooperatively. Strikingly, Hnrnph1 germline-specific mutant female mice were also infertile, and Hnrnph1-deficient oocytes exhibited a similar defective synapsis and cell-cell junction as shown in Hnrnph1-deficient male germ cells. Collectively, our data reveal an essential role for hnRNPH1 in regulating pre-mRNA splicing during spermatogenesis and oogenesis and support a molecular model whereby hnRNPH1 governs a network of alternative splicing events in germ cells via recruiting PTBP2 and SRSF3.


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