scholarly journals Very Small Embryonic-Like Stem Cells: Implications in Reproductive Biology

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Deepa Bhartiya ◽  
Sreepoorna Unni ◽  
Seema Parte ◽  
Sandhya Anand
Keyword(s):  
Stem Cells ◽  
Germ Cells ◽  
Asymmetric Cell Division ◽  
Functional Unit ◽  
Primordial Germ Cells ◽  
Primordial Follicle ◽  
Human Reproduction ◽  
Primordial Follicles ◽  
Epiblast Stem Cells ◽  
Reproductive Processes

The most primitive germ cells in adult mammalian testis are the spermatogonial stem cells (SSCs) whereas primordial follicles (PFs) are considered the fundamental functional unit in ovary. However, this central dogma has recently been modified with the identification of a novel population of very small embryonic-like stem cells (VSELs) in the adult mammalian gonads. These stem cells are more primitive to SSCs and are also implicated during postnatal ovarian neo-oogenesis and primordial follicle assembly. VSELs are pluripotent in nature and characterized by nuclear Oct-4A, cell surface SSEA-4, and other pluripotent markers like Nanog, Sox2, and TERT. VSELs are considered to be the descendants of epiblast stem cells and possibly the primordial germ cells that persist into adulthood and undergo asymmetric cell division to replenish the gonadal germ cells throughout life. Elucidation of their role during infertility, endometrial repair, superovulation, and pathogenesis of various reproductive diseases like PCOS, endometriosis, cancer, and so on needs to be addressed. Hence, a detailed review of current understanding of VSEL biology is pertinent, which will hopefully open up new avenues for research to better understand various reproductive processes and cancers. It will also be relevant for future regenerative medicine, translational research, and clinical applications in human reproduction.

scholarly journals Formative pluripotent stem cells show features of epiblast cells poised for gastrulation

Cell Research ◽  
2021 ◽  
Author(s):  
Xiaoxiao Wang ◽  
Yunlong Xiang ◽  
Yang Yu ◽  
Ran Wang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Germ Cells ◽  
Pluripotent Stem Cells ◽  
Primordial Germ Cells ◽  
Embryonic Stem ◽  
Large Set ◽  
Mouse Escs ◽  
Epiblast Stem Cells ◽  
Early Gastrula

AbstractThe pluripotency of mammalian early and late epiblast could be recapitulated by naïve embryonic stem cells (ESCs) and primed epiblast stem cells (EpiSCs), respectively. However, these two states of pluripotency may not be sufficient to reflect the full complexity and developmental potency of the epiblast during mammalian early development. Here we report the establishment of self-renewing formative pluripotent stem cells (fPSCs) which manifest features of epiblast cells poised for gastrulation. fPSCs can be established from different mouse ESCs, pre-/early-gastrula epiblasts and induced PSCs. Similar to pre-/early-gastrula epiblasts, fPSCs show the transcriptomic features of formative pluripotency, which are distinct from naïve ESCs and primed EpiSCs. fPSCs show the unique epigenetic states of E6.5 epiblast, including the super-bivalency of a large set of developmental genes. Just like epiblast cells immediately before gastrulation, fPSCs can efficiently differentiate into three germ layers and primordial germ cells (PGCs) in vitro. Thus, fPSCs highlight the feasibility of using PSCs to explore the development of mammalian epiblast.

scholarly journals Oocyte Survival and Development During Follicle Formation and Folliculogenesis in Mice Lacking Aromatase

2021 ◽  
Author(s):  
Jessica M. Toothaker ◽  
Kristen Roosa ◽  
Alexandra Voss ◽  
Suzanne M. Getman ◽  
Melissa Pepling
Keyword(s):  
Germ Cells ◽  
Ovarian Reserve ◽  
Primordial Germ Cells ◽  
Primordial Follicle ◽  
Follicle Development ◽  
Primordial Follicles ◽  
Survival And Development ◽  
Hemosiderin Deposits

Abstract BackgroundAssembly of oocytes into primordial follicles is essential for establishing the ovarian reserve required for female fertility. In mice, this process begins during embryonic development. Primordial germ cells form cysts by incomplete mitosis until 13.5 days post coitum (dpc). These cysts break down just before birth. Some oocytes undergo apoptosis while surviving oocytes are enclosed by granulosa cells to form primordial follicles. Cyst breakdown and primordial follicle formation were previously shown to be inhibited by estradiol and estrogenic compounds in vitro, suggesting that estrogen is important for regulation of this process. MethodsTo determine the role of fetal estrogen in cyst breakdown and follicle formation these processes were quantified in aromatase deficient (ArKO) mice between 17.5 dpc and postnatal day (PND) 9. Ovaries of ArKO mice were also examined at 2-week intervals to determine if folliculogenesis is affected by lack of estrogen and the age at which the typical ArKO ovarian phenotype first appears. ResultsOocyte number, follicle assembly and follicle development in ArKO mice did not differ from controls between 17.5 dpc and PND9 except for a difference in the proportion of follicles at the primordial and primary stage at PND7. At 2 weeks, ArKO heterozygous and homozygous ovaries still had oocytes in cyst while all oocytes were enclosed in follicles in wildtype ovaries. From 2 to 8 weeks oocyte numbers were similar in all genotypes though there was a trend toward fewer total oocytes in ArKO homozygous females as compared to controls at 8 weeks and a significant reduction at 10 weeks. Abnormal structures such as hemorrhagic follicles and hemosiderin deposits were also observed starting at 6 weeks. ConclusionsThese results suggest that a lack of fetal estrogen does not affect the rate of cyst breakdown or primordial follicle formation perinatally, and maternal estrogen or other signals are the chief regulators. Furthermore, the typical ArKO ovarian phenotype occurs earlier than previously reported.

Expression and intracellular localization of Nanos2-homologue protein in primordial germ cells and spermatogonial stem cells

Zygote ◽  
2019 ◽  
Vol 27 (02) ◽  
pp. 82-88 ◽  
Author(s):  
Vivek Pandey ◽  
Anima Tripathi ◽  
Pawan K. Dubey
Keyword(s):  
Stem Cells ◽  
Flow Cytometry ◽  
Germ Cells ◽  
Expression Patterns ◽  
Intracellular Localization ◽  
Primordial Germ Cells ◽  
Type A ◽  
Spermatogonial Stem Cells ◽  
Single Type ◽  
Rt Pcr

SummaryThe decision by germ cells to differentiate and undergo either oogenesis or spermatogenesis takes place during embryonic development and Nanos plays an important role in this process. The present study was designed to investigate the expression patterns in rat of Nanos2-homologue protein in primordial germ cells (PGCs) over different embryonic developmental days as well as in spermatogonial stem cells (SSCs). Embryos from three different embryonic days (E8.5, E10.5, E11.5) and SSCs were isolated and used to detect Nanos2-homologue protein using immunocytochemistry, western blotting, reverse transcription polymerase chain reaction (RT-PCR) and flow cytometry. Interestingly, Nanos2 expression was detected in PGCs at day E11.5 onwards and up to colonization of PGCs in the genital ridge of fetal gonads. No Nanos2 expression was found in PGCs during early embryonic days (E8.5 and 10.5). Furthermore, immunohistochemical and immunofluorescence data revealed that Nanos2 expression was restricted within a subpopulation of undifferentiated spermatogonia (As, single type A SSCs and Apr, paired type A SSCs). The same results were confirmed by our western blot and RT-PCR data, as Nanos2 protein and transcripts were detected only in PGCs from day E11.5 and in undifferentiated spermatogonia (As and Apr). Furthermore, Nanos2-positive cells were also immunodetected and sorted using flow cytometry from the THY1-positive SSCs population, and this strengthened the idea that these cells are stem cells. Our findings suggested that stage-specific expression of Nanos2 occurred on different embryonic developmental days, while during the postnatal period Nanos2 expression is restricted to As and Apr SSCs.

Collagen-alginate microspheres as a 3D culture system for mouse embryonic stem cells differentiation to primordial germ cells

Biologicals ◽  
2017 ◽  
Vol 48 ◽  
pp. 114-120 ◽  
Author(s):  
Vahid Mansouri ◽  
Mohammad Salehi ◽  
Mir davood Omrani ◽  
Zahra Niknam ◽  
Abdolreza Ardeshirylajimi
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Germ Cells ◽  
Culture System ◽  
Primordial Germ Cells ◽  
Embryonic Stem ◽  
3D Culture ◽  
Mouse Embryonic Stem Cells ◽  
3D Culture System

scholarly journals Follistatin Regulates Germ Cell Nest Breakdown and Primordial Follicle Formation

Endocrinology ◽  
2010 ◽  
Vol 152 (2) ◽  
pp. 697-706 ◽  
Author(s):  
Fuminori Kimura ◽  
Lara M. Bonomi ◽  
Alan L. Schneyer
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Ovarian Function ◽  
Primordial Follicle ◽  
Biochemical Properties ◽  
The Body ◽  
Protein Isoforms ◽  
Primordial Follicles ◽  
Reduced Rate ◽  
Regulatory Functions

Abstract Follistatin (FST) is an antagonist of activin and related TGFβ superfamily members that has important reproductive actions as well as critical regulatory functions in other tissues and systems. FST is produced as three protein isoforms that differ in their biochemical properties and in their localization within the body. We created FST288-only mice that only express the short FST288 isoform and previously reported that females are subfertile, but have an excess of primordial follicles on postnatal day (PND) 8.5 that undergo accelerated demise in adults. We have now examined germ cell nest breakdown and primordial follicle formation in the critical PND 0.5–8.5 period to test the hypothesis that the excess primordial follicles derive from increased proliferation and decreased apoptosis during germ cell nest breakdown. Using double immunofluorescence microscopy we found that there is virtually no germ cell proliferation after birth in wild-type or FST288-only females. However, the entire process of germ cell nest breakdown was extended in time (through at least PND 8.5) and apoptosis was significantly reduced in FST288-only females. In addition, FST288-only females are born with more germ cells within the nests. Thus, the excess primordial follicles in FST288-only mice derive from a greater number of germ cells at birth as well as a reduced rate of apoptosis during nest breakdown. These results also demonstrate that FST is critical for normal regulation of germ cell nest breakdown and that loss of the FST303 and/or FST315 isoforms leads to excess primordial follicles with accelerated demise, resulting in premature cessation of ovarian function.

154 MOLECULAR CHARACTERIZATION OF CAT PRIMORDIAL GERM CELLS

2016 ◽  
Vol 28 (2) ◽  
pp. 207
Author(s):  
J. Galiguis ◽  
C. E. Pope ◽  
C. Dumas ◽  
G. Wang ◽  
R. A. MacLean ◽  
...  
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Embryonic Stem ◽  
Transcript Abundance ◽  
Domestic Cat ◽  
Sample Type

As precursors to germline stem cells and gametes, there are many potential applications for primordial germ cells (PGC). Primordial germ cell-like cells have been generated from mouse embryonic stem cells and induced pluripotent stem cells, which subsequently were used to produce functional spermatozoa, oocytes, and healthy offspring (Hayashi et al. 2012 Science 338(6109), 971–975). Applying this approach to generate sperm and oocytes of endangered species is an appealing prospect. Detection of molecular markers associated with PGC is essential to optimizing the process of PGC induction. In the current study, in vitro-derived domestic cat embryos were assessed at various developmental stages to characterise the expression of markers related to the specification process of cat PGC. In vivo-matured, IVF oocytes were cultured until Days 7, 9, and 12 post-insemination. Then, embryos were assessed by RT-qPCR to determine relative transcript abundance of the pluripotency markers NANOG, POU5F1, and SOX2; the epiblast marker DNMT3B; the primitive endoderm marker GATA4; the PGC marker PRDM14; and the germ cell marker VASA; RPS19 was used as the internal reference gene. To validate the qPCR results, fibroblasts served as the negative control cells, whereas spermatogonial stem cells (SSC) served as the positive control cells for GATA4, PRDM14, and VASA. Total mRNA were isolated using the Cells-to-cDNA™ II Kit (Ambion/Thermo Fisher Scientific, Waltham, MA, USA) from either pools of 2 to 6 embryos or ~25 000 fibroblasts/SSC. A minimum of 2 biological replicates for each sample type was analysed, with transcript abundance detected in 2 technical replicates by SYBR Green chemistry. Student’s t-tests were performed on the ΔCts for statistical analysis. PRDM14, specific to the germ cell lineage, was detected as early as Day 7, suggesting the presence of PGC precursor cells. Compared with their levels at Day 7, PRDM14 expression was 0.34-fold lower in SSC (P < 0.05), whereas expression of VASA and GATA4 were 1964-fold and 144-fold higher, respectively (P < 0.05). This seems to emphasise the relative importance of PRDM14 in pre-germ cell stages. In general, all genes analysed were up-regulated from Day 7 to Day 9. This up-regulation was statistically significant for SOX2 and GATA4 (P < 0.05). Relative to that at Day 9, all transcripts were relatively less abundant at Day 12 (P < 0.05 for NANOG, POU5F1, SOX2, DNMT3B, and PRDM14). The data suggest that PGC specification takes place near Day 9, with peak specification activity concluding by Day 12. Although much needs be explored about PGC specification in the cat before applying induction and in vitro germ cell production techniques, these findings represent the first step towards a new potential strategy for preserving endangered and threatened felids.

BMP4 can generate primordial germ cells from bone-marrow-derived pluripotent stem cells

2012 ◽  
Vol 36 (12) ◽  
pp. 1185-1193 ◽  
Author(s):  
Reza Shirazi ◽  
Amir Hassan Zarnani ◽  
Masoud Soleimani ◽  
Mir Abbas Abdolvahabi ◽  
Karim Nayernia ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Germ Cells ◽  
Pluripotent Stem Cells ◽  
Primordial Germ Cells

scholarly journals Follicular assembly: mechanisms of action

Reproduction ◽  
2012 ◽  
Vol 143 (2) ◽  
pp. 139-149 ◽  
Author(s):  
Melissa E Pepling
Keyword(s):  
Cell Death ◽  
Germ Line ◽  
Primordial Germ Cells ◽  
Primordial Follicle ◽  
Mechanisms Of Action ◽  
Initial Number ◽  
Primordial Follicles ◽  
Meiotic Progression ◽  
Germ Cell Cysts ◽  
Reproductive Cancers

The differentiation of primordial germ cells (PGCs) into functional oocytes is important for the continuation of species. In mammals, PGCs begin to differentiate into oocytes during embryonic development. Oocytes develop in clusters called germ line cysts. During fetal or neonatal development, germ cell cysts break apart into single oocytes that become surrounded by pregranulosa cells to form primordial follicles. During the process of cyst breakdown, a subset of cells in each cyst undergoes cell death with only one-third of the initial number of oocytes surviving to form primordial follicles. The mechanisms that control cyst breakdown, oocyte survival, and follicle assembly are currently under investigation. This review describes the mechanisms that have been implicated in the control of primordial follicle formation, which include programmed cell death regulation, growth factor and other signaling pathways, regulation by transcription factors and hormones, meiotic progression, and changes in cell adhesion. Elucidation of mechanisms leading to formation of the primordial follicle pool will help research efforts in ovarian biology and improve treatments of female infertility, premature ovarian failure, and reproductive cancers.

Sign in / Sign up

Export Citation Format

Share Document