scholarly journals Characterization of Telomeric Repeat-Containing RNA (TERRA) localization and protein interactions in Primordial Germ Cells of the mouse

2018 ◽  
Author(s):  
Miguel Angel Brieno-Enriquez ◽  
Stefannie L. Moak ◽  
Anyul Abud-Flores ◽  
Paula Elaine Cohen

Telomeres are dynamic nucleoprotein structures capping the physical ends of linear eukaryotic chromosomes. They consist of telomeric DNA repeats (TTAGGG), the shelterin protein complex, and Telomeric Repeat-Containing RNA (TERRA). Proposed TERRA functions are wide-ranging and include telomere maintenance, telomerase inhibition, genomic stability, and alternative lengthening of telomere. However, the role of TERRA in primordial germ cells (PGCs), the embryonic precursors of germ cells, is unknown. Using RNA-fluorescence in situ hybridization (RNA-FISH) we identify TERRA in PGCs soon after these cells have migrated to, and become established in, the developing gonad. RNA-FISH showed the presence of TERRA transcripts in female PGCs at 11.5, 12.5 and 13.5 days post-coitum. In male PGCs, however, TERRA transcripts are observable from 12.5 dpc. Using qPCR we evaluated chromosome-specific TERRA expression, and demonstrated that TERRA levels vary with sex and gestational age, and that transcription of TERRA from specific chromosomes is sexually dimorphic. TERRA interacting proteins were evaluated using Identification of Direct RNA Interacting Proteins (iDRiP) which identified 48 in female and 26 in male protein interactors specifically within nuclear extracts from PGCs at 13.5 dpc. We validated two different proteins the splicing factor, proline- and glutamine-rich (SFPQ) in PGCs and Non-POU domain-containing octamer-binding protein (NONO) in somatic cells. Our results show that, TERRA interacting proteins are determined by sex in both PGCs and somatic cells. Taken together, our data indicate that TERRA expression and interactome during PGC development are regulated in a dynamic fashion that is dependent on gestational age and sex.

2018 ◽  
Vol 100 (4) ◽  
pp. 950-962 ◽  
Author(s):  
Miguel A Brieño-Enríquez ◽  
Steffanie L Moak ◽  
Anyul Abud-Flores ◽  
Paula E Cohen

2017 ◽  
Author(s):  
Chih-Yung S. Lee ◽  
Tu Lu ◽  
Geraldine Seydoux

AbstractThe Nanos RNA-binding protein has been implicated in the specification of primordial germ cells (PGCs) in metazoans, but the underlying mechanisms remain poorly understood. We have profiled the transcriptome of PGCs lacking the nanos homologues nos-1 and nos-2 iC. elegans. nos-1nos-2 PGCs fail to silence hundreds of genes normally expressed in oocytes and somatic cells, a phenotype reminiscent of PGCs lacking the repressive PRC2 complex. The nos-1nos-2 phenotype depends on LIN-15B, a broadly expressed synMuvB class transcription factor known to antagonize PRC2 activity in somatic cells. LIN-15B is maternally-inherited by all embryonic cells and is down-regulated specifically in PGCs in a nos-1nos-2-dependent manner. Consistent with LIN-15B being a critical target of Nanos regulation, inactivation of maternal LIN-15B restores fertility to nos-1nos-2 mutants. These studies demonstrate a central role for Nanos in reprogramming the transcriptome of PGCs away from an oocyte/somatic fate by down-regulating an antagonist of PRC2 activity.


Author(s):  
Rafał P. Piprek ◽  
Malgorzata Kloc ◽  
Paulina Mizia ◽  
Jacek Z. KUBIAK

Cadherins are a group of membrane proteins responsible for cell adhesion. They are crucial for cell sorting and recognition during the morphogenesis, but also play many other roles such as assuring tissue integrity and resistance to stretching, mechanotransduction, cell signaling, regulation of cell proliferation, apoptosis, survival, carcinogenesis, etc. Within the cadherin superfamily, the E- and N-cadherin have been especially well studied. They are involved in many aspects of sexual development and reproduction, such as germline development and gametogenesis, gonad development and functioning, and fertilization. E-cadherin is expressed in the primordial germ cells, (PGCs) and also participates in PGC migration to the developing gonads where they become enclosed by the N-cadherin-expressing somatic cells. The differential expression of cadherins is also responsible for the establishment of the testis or ovary structure. In the adult testes, the N-cadherin is responsible for the integrity of the seminiferous epithelium, regulation of sperm production, and the establishment of the blood-testis barrier. Sex hormones regulate the expression and turnover of N-cadherin influencing the course of spermatogenesis. In the adult ovaries, E- and N-cadherin assure the integrity of ovarian follicles and the formation of corpora lutea. Cadherins are expressed in the mature gametes, and facilitate the capacitation of sperm in the female reproductive tract, and gamete contact during fertilization. The germ cells and accompanying somatic cells express a series of different cadherins, however, their role in gonads and reproduction is still unknown. In this review, we show what is known and unknown about the role of cadherins in the germline and gonad development, and suggest the topics for future research.


Author(s):  
Peter H Vogt ◽  
Jutta Zimmer ◽  
Ulrike Bender ◽  
Thomas Strowitzki

The Ubiquitous Transcribed Y (UTY) AZFa candidate gene on the human Y chromosome and its paralog on the X chromosome, UTX, encode a histone lysine demethylase removing chromatin H3K27 methylation marks at genes transcriptional start sites for activation. Both proteins harbour the conserved Jumonji C (JmjC) domain, functional in chromatin metabolism, and an extended N-terminal tetratrico peptide repeat (TPR) block involved in specific protein-interactions. Specific antisera for human UTY and UTX proteins were developed to distinguish expression of both proteins in human germ cells by immunohistochemical experiments on appropriate tissue sections. In the male germ line, UTY was expressed in the fraction of A spermatogonia located at the basal membrane probably including spermatogonia stem cells. UTX expression was more spread in all spermatogonia and in early spermatids. In female germ line, UTX expression was found in the primordial germ cells of the ovary. UTY was also expressed during fetal male germ cell development, whereas UTX expression was visible only at distinct gestation weeks. Based on these results and the conserved neighboured location of UTY and DDX3Y in Yq11 found in mammals of distinct lineages, we conclude that UTY –like DDX3Y- is part of the Azoospermia factor a (AZFa) locus functioning in human spermatogonia to support the balance of their proliferation-differentiation rate before meiosis. Comparable UTY and DDX3Y expression was also found in gonadoblastoma and dysgerminoma cells found in germ cell nests of the dysgenetic gonads of individuals with disorders of sexual development and a Y chromosome in karyotype (DSD-XY). This confirms that AZFa overlaps with GBY, the Gonadoblastoma susceptibility Y locus, and includes the UTY gene.


Development ◽  
2002 ◽  
Vol 129 (5) ◽  
pp. 1155-1164 ◽  
Author(s):  
Ian R. Adams ◽  
Anne McLaren

During embryogenesis, primordial germ cells (PGCs) have the potential to enter either spermatogenesis or oogenesis. In a female genital ridge, or in a non-gonadal environment, PGCs develop as meiotic oocytes. However, male gonadal somatic cells inhibit PGCs from entering meiosis and direct them to a spermatogenic fate. We have examined the ability of PGCs from male and female embryos to respond to the masculinising environment of the male genital ridge, defining a temporal window during which PGCs retain a bipotential fate. To help understand how PGCs respond to the male gonadal environment, we have identified molecular differences between male PGCs that are committed to spermatogenesis and bipotential female PGCs. Our results suggest that one way in which PGCs respond to this masculinising environment is to synthesise prostaglandin D2. We show that this signalling molecule can partially masculinise female embryonic gonads in culture, probably by inducing female supporting cells to differentiate into Sertoli cells. In the developing testis, prostaglandin D2 may act as a paracrine factor to induce Sertoli cell differentiation. Thus part of the response of PGCs to the male gonadal environment is to generate a masculinising feedback loop to ensure male differentiation of the surrounding gonadal somatic cells.


2021 ◽  
Author(s):  
Ruifeng Zhao ◽  
Qisheng Zuo ◽  
Xia Yuan ◽  
Kai Jin ◽  
Yani Zhang ◽  
...  

Abstract The chicken primordial germ cell (PGCs) has the unique characteristic of settling in gonad through blood migration, which was the only way to realize the recovery of bird species. However, the PGCs obtained from a single embryo was far from enough to meet the practical application, while somatic cells can be obtained in large quantities. Therefore, the problem of insufficient PGCs can be solved by the induction of somatic cells into PGCs. Here, we successfully transdifferentiate somatic cells into PGCs, which can be transplanted to the recipient to produce offspring. In detail, The CEF of Black-Feathered Langshan Chicken was reprogrammed into iPS by reprogramming factors Oct4, Sox2, Nanog and Lin28, then was induced into PGCs by BMP4/BMP8b/EGF system. The induced PGCs has similar biological characteristics to the primary PGCs, which was transplanted into White Plymouth Rock Chicken, which self-crossed to produce clone-like offspring. It was the the first time to demonstrate the feasibility of avian cloning from somatic cells.


Zygote ◽  
2011 ◽  
Vol 20 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Susa Shin ◽  
Kwang Sung Ahn ◽  
Seong-Jun Choi ◽  
Soon Young Heo ◽  
Hosup Shim

SummaryUndifferentiated stem cells may support a greater development of cloned embryos compared with differentiated cell types due to their ease of reprogramming during the nuclear transfer (NT) process. Hence, stem cells may be more suitable as nuclear donor cells for NT procedures than are somatic cells. Embryonic germ (EG) cells are undifferentiated stem cells that are isolated from cultured primordial germ cells (PGC) and can differentiate into several cell types. In this study, the in vitro development of NT embryos using porcine EG cells and their derivative neural precursor (NP) cells was investigated, thus eliminating any variation in genetic differences. The rates of fusion did not differ between NT embryos from EG and NP cells; however, the rate of cleavage in NT embryos derived from EG cells was significantly higher (p < 0.05) than that from NP cells (141/247 [57.1%] vs. 105/228 [46.1%]). Similarly, the rate of blastocyst development was significantly higher (P < 0.05) in NT using EG cells than the rate using NP cells (43/247 [17.4%] vs. 18/228 [7.9%]). The results obtained from the present study in pigs demonstrate a reduced capability for nuclear donor cells to be reprogrammed following the differentiation of porcine EG cells. Undifferentiated EG cells may be more amenable to reprogramming after reconstruction compared with differentiated somatic cells.


Zygote ◽  
1997 ◽  
Vol 5 (2) ◽  
pp. 139-151 ◽  
Author(s):  
Jennifer E. Frick ◽  
Edward E. Ruppert

SummaryPrimordial germ cells (PGCs) are described from the gonad of c. 2 cm juvenile Branchiostoma virginiae; early oocytes (c. 10 μm) and enlarging, previtellogenic oocytes (c. 35 μm) are described from the ovary of c. 5 cm adults. The germinal epithelium of the juvenile gonad and adult ovary is composed of both germinal and somatic cells. In the juvenile, somatic cells retain contact with the basal lamina of the germinal epithelium though their perikarya may be displaced towards the lumen; the germinal epithelium is, therefore, a simple but pseudostratified epithelium. In the adult ovary, somatic cells may lose contact with the basal lamina and the epithelium appears to become stratified. PGCs and oocytes are identified as germ cells by the presence of nuage. PGCs and oocytes are polarised epithelial cells. They rest on a basal lamina, extend apically towards a lumen, form adhering junctions with neighbouring cells, and exhibit apical-basal polarity. PGCs and early oocytes have an apical flagellum with an associated basal body, accessory centriole, and one or more striated rootlet fibres. The flagellum is surrounded by a collar of microvilli. Once oocytes begin to enlarge and bulge basally into the connective tissue layer, the flagellum is lost, but the basal bodies and ciliary rootlets are present at the apex of 35 μm oocytes. Similarities of the oogenic pattern in cephalochordates and echinoderms indicate that the establishment of egg polarity in deuterostomes is influenced by the polarity of the germinal epithelium.


2020 ◽  
Vol 21 (21) ◽  
pp. 8264
Author(s):  
Rafał P. Piprek ◽  
Malgorzata Kloc ◽  
Paulina Mizia ◽  
Jacek Z. Kubiak

Cadherins are a group of membrane proteins responsible for cell adhesion. They are crucial for cell sorting and recognition during the morphogenesis, but they also play many other roles such as assuring tissue integrity and resistance to stretching, mechanotransduction, cell signaling, regulation of cell proliferation, apoptosis, survival, carcinogenesis, etc. Within the cadherin superfamily, E- and N-cadherin have been especially well studied. They are involved in many aspects of sexual development and reproduction, such as germline development and gametogenesis, gonad development and functioning, and fertilization. E-cadherin is expressed in the primordial germ cells (PGCs) and also participates in PGC migration to the developing gonads where they become enclosed by the N-cadherin-expressing somatic cells. The differential expression of cadherins is also responsible for the establishment of the testis or ovary structure. In the adult testes, N-cadherin is responsible for the integrity of the seminiferous epithelium, regulation of sperm production, and the establishment of the blood–testis barrier. Sex hormones regulate the expression and turnover of N-cadherin influencing the course of spermatogenesis. In the adult ovaries, E- and N-cadherin assure the integrity of ovarian follicles and the formation of corpora lutea. Cadherins are expressed in the mature gametes and facilitate the capacitation of sperm in the female reproductive tract and gamete contact during fertilization. The germ cells and accompanying somatic cells express a series of different cadherins; however, their role in gonads and reproduction is still unknown. In this review, we show what is known and unknown about the role of cadherins in the germline and gonad development, and we suggest topics for future research.


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