Oogenesis in an Adult Prosimian

Butler, H.; Juma, M. B.

doi:10.1038/226552a0

Cited by 25 publications

(28 citation statements)

References 2 publications

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“…However, this proposal is a matter of current debate with different studies presenting evidence claiming for and against the existence of de novo oogenesis (Tilly et al 2009, Gougeon 2010. De novo oogenesis has been reported in several species of lorises (Butler & Juma 1970, David et al 1974 in which nests of dividing oogonia persist in the adult ovary. It has been claimed that this may represent an isolated phenomenon of some prosimian species as such germ cell nests do not seem to occur in the adult ovary in rodents (Kerr et al 2006).…”

Section: Discussionmentioning

confidence: 99%

Quantification of healthy and atretic germ cells and follicles in the developing and post-natal ovary of the South American plains vizcacha, Lagostomus maximus: evidence of continuous rise of the germinal reserve

et al. 2014

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The female germ line in mammals is subjected to massive cell death that eliminates 60–85% of the germinal reserve by birth and continues from birth to adulthood until the exhaustion of the germinal pool. Germ cell demise occurs mainly through apoptosis by means of a biased expression in favour of pro-apoptotic members of theBCL2gene family. By contrast, the South American plains vizcacha,Lagostomus maximus, exhibits sustained expression of the anti-apoptoticBCL2gene throughout gestation and a low incidence of germ cell apoptosis. This led to the proposal that, in the absence of death mechanisms other than apoptosis, the female germ line should increase continuously from foetal life until after birth. In this study, we quantified all healthy germ cells and follicles in the ovaries ofL. maximusfrom early foetal life to day 60 after birth using unbiased stereological methods and detected apoptosis by labelling with TUNEL assay. The healthy germ cell population increased continuously from early-developing ovary reaching a 50 times higher population number by the end of gestation. TUNEL-positive germ cells were <0.5% of the germ cell number, except at mid-gestation (3.62%). Mitotic proliferation, entrance into prophase I stage and primordial follicle formation occurred as overlapping processes from early pregnancy to birth. Germ cell number remained constant in early post-natal life, but a remnant population of non-follicular VASA- and PCNA-positive germ cells still persisted at post-natal day 60.L. maximusis the first mammal so far described in which female germ line develops in the absence of constitutive massive germ cell elimination.Free Spanish abstractSpanish translation of this abstract is freely available athttp://www.reproduction-online.org/content/147/2/199/suppl/DC1

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Section: Discussionmentioning

confidence: 99%

Quantification of healthy and atretic germ cells and follicles in the developing and post-natal ovary of the South American plains vizcacha, Lagostomus maximus: evidence of continuous rise of the germinal reserve

et al. 2014

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“…Our findings are in broad agreement with this interpretation. Oogenesis leading to the formation of new oocytes has been reported in immature and adult ovaries of several primate species (Duke 1967, Ioannu 1967, Butler & Juma 1970, David et al 1974.…”

Section: Discussionmentioning

confidence: 99%

“…The notion of a fixed, non-renewable reserve of primordial follicles has been questioned by several earlier studies of primate species, where in adult ovaries mitotically active germ cells in nests or single oogonia have been reported (Vermande-van Eck 1956, Duke 1967, Ioannou 1967, Butler & Juma 1970, David et al 1974. Adult ovaries of Drosophila contain germline stem cells that renew oocyte supply (Lin & Spradling 1995, Deng & Lin 2001, Wang & Lin 2004.…”

Section: Introductionmentioning

confidence: 99%

Quantification of healthy follicles in the neonatal and adult mouse ovary: evidence for maintenance of primordial follicle supply

Kerr¹,

Duckett²,

Myers³

et al. 2006

Reproduction

193

180

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Proliferation and partial meiotic maturation of germ cells in fetal ovaries is believed to establish a finite, non-renewable pool of primordial follicles at birth. The supply of primordial follicles in postnatal life should be depleted during folliculogenesis, either undergoing atresia or surviving to ovulation. Recent studies of mouse ovaries propose that intra-and extraovarian germline stem cells replenish oocytes and form new primordial follicles. We quantified all healthy follicles in C57BL/6 mouse ovaries from day 1 to 200 using unbiased stereological methods, immunolabelling of oocyte meiosis (germ cell nuclear antigen (GCNA)) and ovarian cell proliferation (proliferating cell nuclear antigen (PCNA)) and electronmicroscopy. Day 1 ovaries contained 7924G1564 (S.E.M.) oocytes or primordial follicles, declining on day 7 to 1987G203, with 200-800 oocytes ejected from individual ovaries on that day and day 12. Discarded oocytes and those subjacent to the surface epithelium were GCNA-positive indicating their incomplete meiotic maturation. From day 7 to 100 mean numbers of primordial follicles per ovary were not significantly depleted but declined at 200 days to 254G71. Mean numbers of all healthy follicles per ovary were not significantly different from day 7 to 100 (range 2332G349-3007G322). Primordial follicle oocytes were PCNA-negative. Occasional unidentified cells were PCNA-positive with mitotic figures observed in the cortex of day 1 and 12 ovaries. Although we found no evidence for ovarian germline stem cells, our data support the hypothesis of postnatal follicle renewal in postnatal and adult ovaries of C57BL/6 mice. Reproduction (2006) 132 95-109

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“…Although many studies (1)(2)(3)(4)(5)(6) have been done to understand the mechanism of follicular development in the very small follicles, it has not been clarified because they appear to grow at a very slow speed. Therefore, a new direct analytical method has been needed.…”

mentioning

confidence: 99%

“…It is widely known that a rat's oocyte doubles its DNA in the embryonal stage and its mitosis is arrested until resumption of the first meiotic division just before ovulation (2,9). We noticed this phenomenon could be available to label a certain group of oocyte's nuclei in the embryonal stage.…”

mentioning

confidence: 99%

BrdU Labelling of Fetus Oocytes in the Rat.

Fujimori

Seki

Ito

et al. 1994

Acta Histochem. Cytochem

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To analyze dynamically the development of small follicles in the immature rat, a cohort of follicles was set up by labelling a certain group of oocyte's nuclei in the embryonal stage. The pregnant rats were transabdominally injected with bromodeoxyuridine (BrdU) in the 17th day of pregnancy.The litters were sacrificed at 1, 2, 3 and 4 weeks after birth to localize BrdU in the ovaries and the livers by immunohistochemistry with anti-BrdU antibody.The BrdU staining was evident mainly in the nuclei of oocytes in primordial follicles through 1 to 4 weeks, while live cells were not stained after the 2nd week, indicating that the fetal oocyte escaped the dilution of BrdU uptaken due to arrest of its mitosis. The primordial follicles occupied 100% of the BrdU-labelled follicles at the 1st week, 98.8% the 2nd week, 90.9% the 3rd week, and 88.5% the 4th week. However, the majority of antral follicles were unlabeled though only a few vesicular follicles showed BrdU incorporation even at the 4th week. This result suggests about 10% in a given cohort of primordial follicles were developed into the next growing follicles during this period.

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Oogenesis in an Adult Prosimian

Cited by 25 publications

References 2 publications

Quantification of healthy and atretic germ cells and follicles in the developing and post-natal ovary of the South American plains vizcacha, Lagostomus maximus: evidence of continuous rise of the germinal reserve

Quantification of healthy and atretic germ cells and follicles in the developing and post-natal ovary of the South American plains vizcacha, Lagostomus maximus: evidence of continuous rise of the germinal reserve

Quantification of healthy follicles in the neonatal and adult mouse ovary: evidence for maintenance of primordial follicle supply

BrdU Labelling of Fetus Oocytes in the Rat.

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