scholarly journals Multiple mechanisms of germ cell loss in the perinatal mouse ovary

Reproduction ◽  
2009 ◽  
Vol 137 (4) ◽  
pp. 709-720 ◽  
Author(s):  
Patricia Rodrigues ◽  
Darlene Limback ◽  
Lynda K McGinnis ◽  
Carlos E Plancha ◽  
David F Albertini
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Primordial Follicle ◽  
Cell Loss ◽  
Serum Starvation ◽  
Newborn Mouse ◽  
Organ Cultures ◽  
Mouse Ovary ◽  
Internal Factors ◽  
Fetal Period

In the perinatal ovary of most mammals, external and internal factors establish a primordial follicle reserve that specifies the duration of the reproductive lifespan of a given species. We analyzed the mechanism of follicle loss and survival in C57BI/6 mice using static and dynamic assays of apoptosis, autophagy, and ovarian morphogenesis. We confirm an initial loss soon after birth, when about 44% of the germ cells detectable at the end of the fetal period abruptly disappear. The observations that (1) few germ or somatic cells were apoptotic in newborn ovaries, (2) vitally stained organ cultures exhibit active extrusion of non-apoptotic germ cells and (3) germ-cell lysosome amplification occurs at birth suggested that additional mechanisms are involved in perinatal germ cell loss. Newborn mouse ovaries cultured in the pH sensitive dye lysotracker red exhibit an increased incidence of acidified non-apoptotic germ cells when maintained in the absence but not in the presence of serum, implying a role for autophagy in germ cell attrition. Inhibitors of autophagy, but not apoptosis, reduce germ cell acidification induced by serum starvation in ovary organ cultures and protein mediators of both autophagy and apoptosis are expressed at birth. From these findings we suggest that multiple perinatal mechanisms establish the primordial follicle reserve in mice.

GATA-like protein-1 (GLP-1) is required for normal germ cell development during embryonic oogenesis

Reproduction ◽  
2011 ◽  
Vol 141 (2) ◽  
pp. 173-181 ◽  
Author(s):  
Tamara J Strauss ◽  
Diego H Castrillon ◽  
Stephen R Hammes
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Germ Line ◽  
Primordial Follicle ◽  
Cell Loss ◽  
Basement Membranes ◽  
Cell Protein ◽  
Null Mouse ◽  
Cell Functions ◽  
Expression Of Genes

Oogenesis and primordial follicle formation are tightly linked processes, requiring organized and precisely timed communication between somatic and germ cells. Deviations in ovarian cell cross talk, or aberrant gene expression within one of the cell populations, can lead to follicle loss or dysfunction, resulting in infertility. Expression of GATA-like protein-1 (GLP-1) in ovarian somatic cells is required for normal fertility in female mice, as GLP-1 deficiency leads to the absence of oocytes at birth. However, the timing and nature of this germ cell loss is not well understood. In this study, we characterize the embryonic germ cell loss in GLP-1 null mice. Quantitative PCR demonstrates that ovarian Glp-1 mRNA is expressed in a bimodal pattern during embryogenesis, peaking at E13.5–14.5 and again at birth. In contrast, adult ovaries express low but detectable levels of Glp-1 mRNA. Analysis of developing GLP-1 null mouse ovaries shows that germ cells are appropriately specified and migrate normally to nascent gonads. Upon arrival at the gonad, precocious loss of germ cells begins at around E13.5. This loss is completed by birth and is accompanied by defects in the expression of genes associated with meiotic entry. Interestingly, somatic pregranulosa cells still form basement membranes surrounding germ line cysts and express mRNA encoding paracrine signaling molecules that communicate with oocytes, albeit at lower levels than normal. Together, these data imply that the somatic cell protein GLP-1 is not necessary for many pregranulosa cell functions but is required for germ cell survival.

scholarly journals Suppression of Notch Signaling in the Neonatal Mouse Ovary Decreases Primordial Follicle Formation

Endocrinology ◽  
2009 ◽  
Vol 150 (2) ◽  
pp. 1014-1024 ◽  
Author(s):  
Daniel J. Trombly ◽  
Teresa K. Woodruff ◽  
Kelly E. Mayo
Keyword(s):  
Germ Cell ◽  
Notch Signaling ◽  
Cell Fate ◽  
Germ Cells ◽  
Ex Vivo ◽  
Primordial Follicle ◽  
Neonatal Mouse ◽  
Postnatal Life ◽  
Mouse Ovary ◽  
Primordial Follicles

Notch signaling directs cell fate during embryogenesis by influencing cell proliferation, differentiation, and apoptosis. Notch genes are expressed in the adult mouse ovary, and roles for Notch in regulating folliculogenesis are beginning to emerge from mouse genetic models. We investigated how Notch signaling might influence the formation of primordial follicles. Follicle assembly takes place when germ cell syncytia within the ovary break down and germ cells are encapsulated by pregranulosa cells. In the mouse, this occurs during the first 4–5 d of postnatal life. The expression of Notch family genes in the neonatal mouse ovary was determined through RT-PCR measurements. Jagged1, Notch2, and Hes1 transcripts were the most abundantly expressed ligand, receptor, and target gene, respectively. Jagged1 and Hey2 mRNAs were up-regulated over the period of follicle formation. Localization studies demonstrated that JAGGED1 is expressed in germ cells prior to follicle assembly and in the oocytes of primordial follicles. Pregranulosa cells that surround germ cell nests express HES1. In addition, pregranulosa cells of primordial follicles expressed NOTCH2 and Hey2 mRNA. We used an ex vivo ovary culture system to assess the requirement for Notch signaling during early follicle development. Newborn ovaries cultured in the presence of γ-secretase inhibitors, compounds that attenuate Notch signaling, had a marked reduction in primordial follicles compared with vehicle-treated ovaries, and there was a corresponding increase in germ cells that remained within nests. These data support a functional role for Notch signaling in regulating primordial follicle formation. Gamma secretase inhibitor treatment suppresses germ cell nest breakdown in the neonatal mouse ovary, supporting a role for Notch signaling in promoting primordial follicle formation.

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.

scholarly journals Follistatin288 Regulates Germ Cell Cyst Breakdown and Primordial Follicle Assembly in the Mouse Ovary

PLoS ONE ◽  
2015 ◽  
Vol 10 (6) ◽  
pp. e0129643 ◽  
Author(s):  
Zhengpin Wang ◽  
Wanbao Niu ◽  
Yijing Wang ◽  
Zhen Teng ◽  
Jia Wen ◽  
...  
Keyword(s):  
Germ Cell ◽  
Primordial Follicle ◽  
Mouse Ovary

scholarly journals PUMA regulates germ cell loss and primordial follicle endowment in mice

Reproduction ◽  
2014 ◽  
Vol 148 (2) ◽  
pp. 211-219 ◽  
Author(s):  
Michelle Myers ◽  
F Hamish Morgan ◽  
Seng H Liew ◽  
Nadeen Zerafa ◽  
Thilini Upeksha Gamage ◽  
...  
Keyword(s):  
Cell Death ◽  
Germ Cell ◽  
Germ Cells ◽  
Ovarian Development ◽  
Fold Increase ◽  
Cell Loss ◽  
Postnatal Life ◽  
Critical Determinant ◽  
Primordial Follicles ◽  
Female Mice

The number of primordial follicles initially established within the ovary is influenced by the extent of germ cell death during foetal ovarian development, but the mechanisms that mediate this death have not been fully uncovered. In this study, we identified BBC3 (PUMA) (p53 upregulated modulator of apoptosis, also known as BCL2-binding component 3), a pro-apoptotic BH3-only protein belonging to the BCL2 family, as a critical determinant of the number of germ cells during ovarian development. Targeted disruption of the Bbc3 gene revealed a significant increase in the number of germ cells as early as embryonic day 13.5. The number of germ cells remained elevated in Bbc3−/− female mice compared with WT female mice throughout the remainder of embryonic and early postnatal life, resulting in a 1.9-fold increase in the number of primordial follicles in the ovary on postnatal day 10. The increase in the number of germ cells observed in the ovaries of Bbc3−/− mice could not be attributed to the altered proliferative activity of germ cells within the ovaries. Furthermore, BBC3 was found to be not required for the massive germ cell loss that occurs during germ cell nest breakdown. Our data indicate that BBC3 is a critical regulator of germ cell death that acts during the migratory phase of oogenesis or very soon after the arrival of germ cells in the gonad and that BBC3-mediated cell death limits the number of primordial follicles established in the initial ovarian reserve.

scholarly journals Oocyte Arrested at Metaphase II Stage Were Derived From Human Pluripotent Stem Cells in Vitro

2021 ◽  
Author(s):  
Xiaoli Yu ◽  
Ning Wang ◽  
Yingxin Zhang ◽  
Xiang Wang ◽  
Yikai Qiu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Germ Cells ◽  
Pluripotent Stem Cells ◽  
Polar Body ◽  
Primordial Follicle ◽  
Preimplantation Embryos ◽  
Differentiation Potential ◽  
Cell Medium

Abstract BackgroundGeneration and maturation of human oocyte in vitro could facilitate studies of folliculogenesis and oogenesis. We have previously shown that human aminotic fluid stem cells giving rise to oocyte-like cells (OLCs), However, it was difficult to observe whether these OLCs enter meiotic stage. MethodsHuman induced pluripotent stem cells (hiPSCs) and embryonic stem cells (hESCs) were cultured by follicle fluid, cytokines and small molecule to induced oocyte-like cells (OLCs) formation through a three-step induction procedure. Surface marker expression and differentiation potential of germ cells were analyzed in vitro by flow cytometry, gene expression, immunocytochemistry, western blotting and RNA Sequencing.ResultsTo induce hiPSCs differentiation into OLCs, cells were firstly cultured in a primordial germ cell medium for 10 days. The cells showed the morphology similar to primordial germ cells (PGCs), highly expressing germ cell markers and primordial follicle development associated genes. The induced PGCs were then cultured in the primordial follicle-like cell medium for 5 days to form the induced follicle-like structures (iFLs), which retained both primordial oocytes-like cells and granulosa-like cells. In the third step, the detached iFLs were harvested and transferred to the OLC-medium for additional 10 days. The cumulus-oocyte-complexes (COC) structures and OLCs in different sizes (50-150 μm diameter) with zona pellucida were observed. The in vitro matured OLCs presented the polar body and arrested at metaphase II (MII) stage. Some OLCs were self-activated and spontaneously developed into multiple-cell structures similar to preimplantation embryos, indicating that OLCs were parthenogenetically activated though in vitro fertilization potential of OLCs are yet proved.ConclusionsIn vitro maturation of OLCs derived from hiPSCs provides a new means to study human germ cell formation and oogenesis.

The ultrastructure of normal fetal and neonatal pig testis germ cells and the influence of fetal decapitation on the germ cell development

Development ◽  
1987 ◽  
Vol 99 (4) ◽  
pp. 553-563
Author(s):  
C.J. van Vorstenbosch ◽  
E. Spek ◽  
B. Colenbrander ◽  
C.J. Wensing
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Cell Development ◽  
Ultrastructural Organization ◽  
Cross Sectional ◽  
Fetal Period ◽  
Germ Cell Development ◽  
Typical Cell ◽  
Neonatal Pig ◽  
And Control

The development of germ cells in the male pig was investigated ultrastructurally in normal and decapitated fetuses. The age ranged respectively from 30 days p.c. till one month after birth and from 52 days p.c. until birth. The ultrastructural organization of the germ cells changes dramatically between 30 days p.c. and 52 days p.c. which coincides with the formation of ‘true’ sex cords. From 52 days p.c. onwards the morphology is rather stable: cells show a ‘hydrated’ appearance and typical cell bridges. There is no obvious difference in the ultrastructure of germ cells in decapitated animals, their normal littermates and control animals. Therefore germ cell development in the pig is likely to be insensitive to gonadotropins during the fetal period. The development of pig germ cells follows closely the pattern described for several species. Quantitatively there is an increase in the ratio of germ cell/Sertoli cell per cross sectional diameter in the decapitated animals.

scholarly journals The role of germ cell loss during primordial follicle assembly: a review of current advances

2017 ◽  
Vol 13 (4) ◽  
pp. 449-457 ◽  
Author(s):  
Yuan-Chao Sun ◽  
Xiao-Feng Sun ◽  
Paul W. Dyce ◽  
Wei Shen ◽  
Hong Chen
Keyword(s):  
Germ Cell ◽  
Primordial Follicle ◽  
Cell Loss

scholarly journals Absence of mDazl produces a final block on germ cell development at meiosis

Reproduction ◽  
2003 ◽  
pp. 589-597 ◽  
Author(s):  
PT Saunders ◽  
JM Turner ◽  
M Ruggiu ◽  
M Taggart ◽  
PS Burgoyne ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Meiotic Prophase ◽  
Rna Binding ◽  
Developmental Stages ◽  
Cell Loss ◽  
Functional Differentiation ◽  
Autosomal Gene ◽  
Fetal Life ◽  
Male And Female

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.

scholarly journals Deletion of Genes Implicated in Protecting the Integrity of Male Germ Cells Has Differential Effects on the Incidence of DNA Breaks and Germ Cell Loss

PLoS ONE ◽  
2007 ◽  
Vol 2 (10) ◽  
pp. e989 ◽  
Author(s):  
Catriona Paul ◽  
Joanne E. Povey ◽  
Nicola J. Lawrence ◽  
Jim Selfridge ◽  
David W. Melton ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Cell Loss ◽  
Dna Breaks ◽  
Male Germ Cells ◽  
Differential Effects
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