Recently, the existence of a mechanism for neo-oogenesis in the ovaries of adult mammals has generated much controversy within reproductive biology. This mechanism, which proposes that the ovary has cells capable of renewing the follicular reserve, has been described for various species of mammals. The first evidence was found in prosimians and humans. However, these findings were not considered relevant because the predominant dogma for reproductive biology at the time was that of Zuckerman. This dogma states that female mammals are born with finite numbers of oocytes that decline throughout postnatal life. Currently, the concept of neo-oogenesis has gained momentum due to the discovery of cells with mitotic activity in adult ovaries of various mammalian species (mice, humans, rhesus monkeys, domestic animals such as pigs, and wild animals such as bats). Despite these reports, the concept of neo-oogenesis has not been widely accepted by the scientific community, generating much criticism and speculation about its accuracy because it has been impossible to reproduce some evidence. This controversy has led to the creation of two positions: one in favour of neo-oogenesis and the other against it. Various animal models have been used in support of both camps, including both classic laboratory animals and domestic and wild animals. The aim of this review is to critically present the current literature on the subject and to evaluate the arguments pro and contra neo-oogenesis in mammals.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1017/S0967199417000363 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
VSELs and OSCs together sustain oogenesis in adult ovaries and their dysfunction results in age-related senescence, PCOS, POI and cancer.
J Ovarian Res
February 2023
Stem Cell Biology Department, ICMR-National Institute for Research in Reproductive & Child Health, Jehangir Merwanji Street, Parel, Mumbai, 400 012, India.
Multiple studies using single-cell RNA sequencing (scRNAseq) have failed to detect stem cells in adult ovaries. We have maintained that two populations of ovarian stem cells including pluripotent, very small embryonic-like stem cells (VSELs) and tissue-committed 'progenitors' termed ovarian stem cells (OSCs) can easily be detected in Hematoxylin and Eosin-stained ovary surface epithelial (OSE) cells smears prepared from both mice and human ovaries. Most likely the stem cells never get subjected to scRNAseq since they pellet down only by centrifuging cells suspension at 1000 g while cells for scRNAseq were invariably prepared by centrifuging at 200-400 g.
View Article and Find Full Text PDFIdentification of oogonial stem cells in chicken ovary.
Cell Prolif
March 2023
Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, China.
Article Synopsis
- - This study investigates the existence and function of oogonial stem cells (OSCs) in adult chickens, focusing on their role in producing oocytes for egg-laying.
- - Researchers isolated and expanded chicken OSCs in culture and found that these cells can migrate, differentiate, and undergo meiosis when transplanted into embryos.
- - The findings confirm the presence of functional OSCs in birds, which could enhance egg production and aid in the preservation of endangered species.
The Continued Absence of Functional Germline Stem Cells in Adult Ovaries.
Stem Cells
March 2023
Division of Obstetrics and Gynecology, Department of Clinical Science, Intervention and Technology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
Ovaries are central to development, fertility, and reproduction of women. A particularly interesting feature of ovaries is their accelerated aging compared to other tissues, leading to loss of function far before other organs senesce. The limited pool of ovarian follicles is generated before birth and once exhausted, menopause will inevitably commence around the age of 50 years marking the end of fertility.
View Article and Find Full Text PDFDysfunctional Ovarian Stem Cells Due to Neonatal Endocrine Disruption Result in PCOS and Ovarian Insufficiency in Adult Mice.
Stem Cell Rev Rep
December 2022
Stem Cell Biology Department, ICMR- National Institute for Research in Reproductive and Child Health, Jehangir Merwanji Street, Parel, 400 012, Mumbai, India.
Polycystic ovarian syndrome (PCOS) is a common global cause of anovulatory infertility but underlying etiology leading to PCOS still remains elusive. Fetal and perinatal endocrine disruption reportedly affects germ cell nests (GCN) breakdown, meiosis, and primordial follicle (PF) assembly with unassembled oocytes in neonatal ovaries. We recently reported that very small embryonic-like stem cells (VSELs) and ovarian stem cells (OSCs) express ERα, ERβ and FSHR, undergo distinct cyclic changes and neo-oogenesis encompassing GCN formation, meiosis, and primordial follicle (PF) assembly on regular basis in adult mice ovaries and these GCN are arrested in pre-meiotic or early meiotic stage in aged ovaries.
View Article and Find Full Text PDFAged mice ovaries harbor stem cells and germ cell nests but fail to form follicles.
J Ovarian Res
March 2022
Stem Cell Biology Department, ICMR- National Institute for Research in Reproductive Health, Jehangir Merwanji Street, Mumbai, 400, 012, India.
Background: We recently published evidence to suggest that two populations of stem cells including very small embryonic-like stem cells (VSELs) and ovarian stem cells (OSCs) in ovary surface epithelium (OSE) undergo proliferation/differentiation, germ cell nests (GCN) formation, meiosis and eventually differentiate into oocytes that assemble as primordial follicles on regular basis during estrus cycle. Despite presence of stem cells, follicles get exhausted with advancing age in mice and result in senescence equivalent to menopause in women. Stem cells in aged ovaries can differentiate into oocytes upon transplantation into young ovaries, however, it is still not well understood why follicles get depleted with advancing age despite the presence of stem cells.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!