127. PUMA MEDIATES GERM CELL DEATH DURING OVARIAN DEVELOPMENT AND DETERMINES INITIAL PRIMORDIAL FOLLICLE NUMBER IN MICE

2010 ◽  
Vol 22 (9) ◽  
pp. 45
Author(s):  
F. Morgan ◽  
K. J. Hutt ◽  
C. L. Scott ◽  
M. Cook ◽  
A. Strasser ◽  
...  
Keyword(s):  
New York ◽  
Cell Death ◽  
Germ Cell ◽  
Germ Cells ◽  
Ovarian Reserve ◽  
Ovarian Development ◽  
Primordial Follicle ◽  
Primordial Follicles ◽  
Apoptotic Protein ◽  
Programmed Death

The proteins that control the number of primordial follicles initially established within the ovary are largely unknown. Here we investigated the hypothesis that PUMA, a pro-apoptotic protein belonging to the Bcl-2 family, regulates germ cell death during ovarian development and thereby determines the number of primordial follicles that make up the ovarian reserve. Ovaries were obtained from embryonic day 17.5 (E17.5) and post-natal day 10 (PN10) wild-type (wt) and puma–/– mice and subjected to morphological, molecular and stereological characterisation (n = 3-6 mice/genotype/age). At E17.5, ovaries were densely populated with germ cells and early meiotic oocytes. Immunostaining for MVH and PCNA confirmed the identity of germ cells and proliferating germ cells, respectively. Pyknotic nuclei and TUNEL positive germ cells were rarely detected, suggesting that cell death was uncommon at this age. At PN10, primordial follicle assembly was complete for both genotypes, as confirmed morphologically and by immunostaining for oocyte markers GCNA and MSY2. The number of germ cells in E17.5 wt and puma–/– ovaries was comparable (p=0.81, See Table 1). However, PN10 puma–/– ovaries contained significantly more primordial follicles than wt ovaries (P < 0.001, See Table 1), revealing an over-endowment of primordial follicles in the absence of PUMA. These data show that PUMA regulates the developmentally programmed death of germ cells between E17.5 and PN10 in the mouse and thereby determines the number of primordial follicles that make up the initial ovarian reserve. This work was supported by the NHMRC (Program Grants #494802 and #257502, Fellowships JKF (#441101), KJH (#494836), CLS (#406675), AS (#461299)); the Leukemia and Lymphoma Society (New York; SCOR grant#7015), the National Cancer Institute (NIH, US; CA80188 and CA43540) and Victorian Government Infrastructure Funds.

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 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.

Identification of X-Linked Genes Required for Migration and Programmed Cell Death of Drosophila melanogaster Germ Cells

Genetics ◽  
2002 ◽  
Vol 162 (1) ◽  
pp. 273-284 ◽  
Author(s):  
Clark R Coffman ◽  
Rachel C Strohm ◽  
Fredrick D Oakley ◽  
Yukiko Yamada ◽  
Danielle Przychodzin ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Migration ◽  
Germ Cell ◽  
Germ Cells ◽  
Posterior Pole ◽  
Developmentally Regulated ◽  
Regulated Cell Death ◽  
Somatic Gonad ◽  
Programmed Death ◽  
Germ Cell Migration

Abstract Drosophila germ cells form at the posterior pole of the embryo and migrate to the somatic gonad. Approximately 50% of the germ cells that form reach their target. The errant cells within the embryo undergo developmentally regulated cell death. Prior studies have identified some autosomal genes that regulate germ cell migration, but the genes that control germ cell death are not known. To identify X-linked genes required for germ cell migration and/or death, we performed a screen for mutations that disrupt these processes. Here we report the identification of scattershot and outsiders, two genes that regulate the programmed death of germ cells. The scattershot gene is defined by a mutation that disrupts both germ cell migration and the death of germ cells ectopic to the gonad. Maternal and zygotic expression of scattershot is required, but the migration and cell death functions can be genetically uncoupled. Zygotic expression of wild-type scattershot rescues germ cell pathfinding, but does not restore the programmed death of errant cells. The outsiders gene is required zygotically. In outsiders mutant embryos, the appropriate number of germ cells is incorporated into the gonad, but germ cells ectopic to the gonad persist.

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 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.

scholarly journals Transcriptome Landscape Reveals Underlying Mechanisms of Ovarian Cell Fate Differentiation and Primordial Follicle Assembly

2019 ◽  
Author(s):  
Jun-Jie Wang ◽  
Wei Ge ◽  
Qiu-Yue Zhai ◽  
Jing-Cai Liu ◽  
Xiao-Wen Sun ◽  
...  
Keyword(s):  
Germ Cell ◽  
Single Cell ◽  
Cell Fate ◽  
Germ Cells ◽  
Granulosa Cells ◽  
Primordial Follicle ◽  
Gene Clusters ◽  
Bioinformatics Analyses ◽  
Primordial Follicles ◽  
New Genes

AbstractPrimordial follicle assembly in mammals occurs at perinatal ages and largely determines the ovarian reserve available to support the reproductive lifespan. The primordial follicle structure is generated by a complex network of interactions between oocytes and ovarian somatic cells that remain poorly understood. In the present research, using single-cell RNA sequencing performed over a time-series on mouse ovaries coupled with several bioinformatics analyses, the complete dynamic genetic programs of germ and granulosa cells from E16.5 to PD3 are reported for the first time. The time frame of analysis comprises the breakdown of germ cell cysts and the assembly of primordial follicles. Confirming the previously reported expression of genes by germ cells and granulosa cells, our analyses identified ten distinct gene clusters associated to germ cells and eight to granulosa cells. Consequently, several new genes expressed at significant levels at each investigated stage were assigned. Building single-cell pseudo temporal trajectories five states and two branch points of fate transition for the germ cells, and three states and one branch point for the granulosa cells were revealed. Moreover, GO and ClueGO term enrichment enabled identifying biological processes, molecular functions and cellular components more represented in germ cells and granulosa cells or common to both cell types at each specific stage. Finally, by SCENIC algorithm, we were able to establish a network of regulons that can be postulated as likely candidates for sustaining germ cell specific transcription programs throughout the investigated period.

scholarly journals Single-Oocyte Gene Expression Suggests That Curcumin Can Protect the Ovarian Reserve by Regulating the PTEN-AKT-FOXO3a Pathway

2021 ◽  
Vol 22 (12) ◽  
pp. 6570
Author(s):  
Yue Lv ◽  
Rui-Can Cao ◽  
Hong-Bin Liu ◽  
Xian-Wei Su ◽  
Gang Lu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Ovarian Reserve ◽  
Primordial Follicle ◽  
Term Treatment ◽  
New Drugs ◽  
Gene Profiling ◽  
Primordial Follicles ◽  
Long Term Treatment ◽  
Follicle Activation

A better understanding of the mechanism of primordial follicle activation will help us better understand the causes of premature ovarian insufficiency (POI), and will help us identify new drugs that can be applied to the clinical treatment of infertility. In this study, single oocytes were isolated from primordial and primary follicles, and were used for gene profiling with TaqMan array cards. Bioinformatics analysis was performed on the gene expression data, and Ingenuity Pathway Analysis was used to analyze and predict drugs that affect follicle activation. An ovarian in vitro culture system was used to verify the function of the drug candidates, and we found that curcumin maintains the ovarian reserve. Long-term treatment with 100 mg/kg curcumin improved the ovarian reserve indicators of AMH, FSH, and estradiol in aging mice. Mechanistic studies show that curcumin can affect the translocation of FOXO3, thereby inhibiting the PTEN-AKT-FOXO3a pathway and protecting primordial follicles from overactivation. These results suggest that curcumin is a potential drug for the treatment of POI patients and for fertility preservation.

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 Germ cell connectivity enhances cell death in response to DNA damage in the Drosophila testis

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Kevin L Lu ◽  
Yukiko M Yamashita
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Germ Cell ◽  
Germ Cells ◽  
High Sensitivity ◽  
Next Generation ◽  
Drosophila Testis

Two broadly known characteristics of germ cells in many organisms are their development as a ‘cyst’ of interconnected cells and their high sensitivity to DNA damage. Here we provide evidence that in the Drosophila testis, connectivity serves as a mechanism that confers to spermatogonia a high sensitivity to DNA damage. We show that all spermatogonia within a cyst die synchronously even when only a subset of them exhibit detectable DNA damage. Mutants of the fusome, an organelle that is known to facilitate intracyst communication, compromise synchronous spermatogonial death and reduces overall germ cell death. Our data indicate that a death-promoting signal is shared within the cyst, leading to death of the entire cyst. Taken together, we propose that intercellular connectivity supported by the fusome uniquely increases the sensitivity of the germline to DNA damage, thereby protecting the integrity of gamete genomes that are passed on to the next generation.

Sign in / Sign up

Export Citation Format

Share Document