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Journal of Ovarian Research 2014For many years, ovarian biology has been based on the dogma that oocytes reserve in female mammals included a finite number, established before or at birth and it is... (Review)
Review
For many years, ovarian biology has been based on the dogma that oocytes reserve in female mammals included a finite number, established before or at birth and it is determined by the number and quality of primordial follicles developed during the neonatal period. The restricted supply of oocytes in adult female mammals has been disputed in recent years by supporters of postnatal neo-oogenesis. Recent experimental data showed that ovarian surface epithelium and cortical tissue from both mouse and human were proved to contain very low proportion of cells able to propagate themselves, but also to generate immature oocytes in vitro or in vivo, when transplanted into immunodeficient mice ovaries. By mentioning several landmarks of ovarian stem cell reserve and addressing the exciting perspective of translation into clinical practice as treatment for infertility pathologies, the purpose of this article is to review the knowledge about adult mammalian ovarian stem cells, a topic that, since the first approach quickly attracted the attention of both the scientific media and patients.
Topics: Adult; Adult Stem Cells; Animals; Female; Germ Cells; Humans; Models, Animal; Ovary; Stem Cell Niche
PubMed: 25018783
DOI: 10.1186/1757-2215-7-71 -
Zoology (Jena, Germany) Oct 2023Ovaries in earthworms belonging to the family Megascolecidae are paired structures attached to the septum in the anterior part of the XIII segment. They are fan to...
Ovaries in earthworms belonging to the family Megascolecidae are paired structures attached to the septum in the anterior part of the XIII segment. They are fan to rosette shaped with numerous rows of growing oocytes, known as egg strings, radiating from the ovary center towards the segmental cavity. The histological and ultrastructural ovary organization in megascolecids and the course of oogenesis remain unknown. The paper presents the results of light and electron microscopy analyses of ovaries in six megascolecid species, three from the genus Amynthas and three from Metaphire. Both parthenogenetic and sexually reproducing species were included in the study. The organization and ultrastructure of ovaries in all studied species are broadly similar. Considering the histological organization of ovaries, they could be divided into two zones. Zone I (proximal, close to the connection with the septum) is tightly packed with germline and somatic cells. Germ cells are interconnected via intercellular bridges and thin strands of the central cytoplasm (known as cytophore) and form syncytial cysts. Cysts unite oogonia, early meiotic cells (till diplotene), and clustering cells develop synchronously. During diplotene, interconnected cells lose developmental synchrony; most probably, one cell per cyst grows faster than others, detaches from the cysts, and becomes an oocyte. The remaining cells grow slightly and are still interconnected via the thin and reticular cytophore; these cells are considered nurse cells. Zone II has a form of egg strings where growing oocytes are isolated one from another by thin somatic cells and form short cords. We present the ultrastructural details of germline and somatic cells. We propose the term "Amynthas" type of ovaries for this ovary organization. We suppose that such ovaries are characteristic of other megascolecids and related families.
Topics: Humans; Female; Animals; Ovary; Oligochaeta; Oocytes; Oogenesis; Germ Cells
PubMed: 37586295
DOI: 10.1016/j.zool.2023.126109 -
The Journal of Reproduction and... Aug 2019Eggs are female germ cells that are required for producing offspring through sexual reproduction. In mammals, eggs are produced in the ovary and ovulated into the... (Review)
Review
Eggs are female germ cells that are required for producing offspring through sexual reproduction. In mammals, eggs are produced in the ovary and ovulated into the oviduct. It is well known that over 99% of eggs are degenerated without ovulation, so that many studies have attempted in vitro folliculogenesis to produce many eggs in different species for a few decades. Although many methods have been developed, a success of in vitro egg production with the resultant live birth of offspring has been limited, especially in livestock animals. More recently, we have succeeded in producing live pups derived from in vitro/ex vivo egg production in mice. This review aims to introduce our recent findings with a brief history of in vitro/ex vivo culture systems for follicles and ovaries.
Topics: Animals; Cells, Cultured; Female; Humans; In Vitro Oocyte Maturation Techniques; Mammals; Mice; Oocytes; Oogenesis; Ovarian Follicle; Ovary; Ovulation
PubMed: 31006727
DOI: 10.1262/jrd.2019-024 -
Journal of Assisted Reproduction and... Jan 2021To study the effect of aging on ovarian circadian rhythm.
OBJECTIVE
To study the effect of aging on ovarian circadian rhythm.
DESIGN
Human and animal study.
SETTING
University hospital and research laboratory.
PATIENTS/ANIMALS
Human granulosa cells were obtained by follicular aspiration from women undergoing in vitro fertilization (IVF), and ovarian and liver tissues were obtained from female C57BL/6 mice.
INTERVENTION(S)
None.
MAIN OUTCOME MEASURE(S)
Expression of circadian genes in young and older human granulosa cells and circadian rhythm in ovaries and livers of young and older mice.
RESULT(S)
All examined circadian clock genes in human granulosa cells showed a downward trend in expression with aging, and their mRNA expression levels were negatively correlated with age (P < 0.05). Older patients (≥ 40 years of age) had significantly reduced serum anti-Müllerian hormone (AMH) levels. Except for Rev-erbα, all other examined circadian clock genes were positively correlated with the level of AMH (P < 0.05). The circadian rhythm in the ovaries of older mice (8 months) was changed significantly relative to that in ovaries of young mice (12 weeks), although the circadian rhythm in the livers of older mice was basically consistent with that of young mice.
CONCLUSION(S)
Lower ovarian reserve in older women is partially due to ovarian circadian dysrhythmia as a result of aging.
Topics: Aging; Animals; Anti-Mullerian Hormone; Circadian Rhythm; Female; Fertilization in Vitro; Granulosa Cells; Humans; Liver; Mice; Ovarian Reserve; Ovary; RNA, Messenger
PubMed: 32926298
DOI: 10.1007/s10815-020-01943-y -
Aging Jan 2019Aging has been regarded as a treatable condition, and delaying aging could prevent some diseases. Ovarian aging, a special type of organ senescence, is the... (Review)
Review
Aging has been regarded as a treatable condition, and delaying aging could prevent some diseases. Ovarian aging, a special type of organ senescence, is the earliest-aging organ, as ovaries exhibit an accelerated rate of aging with characteristics of gradual declines in ovarian follicle quantity and quality since birth, compared to other organs. Ovarian aging is considered as the pacemaker of female body aging, which drives the aging of multiple organs of the body. Hence, anti-ovarian aging has become a research topic broadly interesting to both biomedical scientists and pharmaceutical industry. A marked progress has been made in exploration of possible anti-ovarian agents or approaches, such as calorie restriction mimetics, antioxidants, autophagy inducers etc., over the past years. This review is attempted to discuss recent advances in the area of anti-ovarian aging pharmacology and to offer new insights into our better understanding of molecular mechanisms underlying ovarian aging, which might be informative for future prevention and treatment of ovarian aging and its related diseases.
Topics: Aging; Animals; Anti-Inflammatory Agents; Antioxidants; Caloric Restriction; Female; Humans; Ovary
PubMed: 30674710
DOI: 10.18632/aging.101784 -
PloS One 2022Understanding the transition from quiescent primordial follicles to activated primary follicles is vital for characterizing ovarian folliculogenesis and improving...
Understanding the transition from quiescent primordial follicles to activated primary follicles is vital for characterizing ovarian folliculogenesis and improving assisted reproductive techniques. To date, no study has investigated preantral follicle crowding in the ovaries of livestock or characterized these crowds according to follicular morphology and ovarian location (portions and regions) in any species. Therefore, the present study aimed to assess the crowding (clustering and neighborhood) patterns of preantral follicles in the equine ovary according to mare age, follicular morphology and developmental stage, and spatial location in the ovary. Ovaries from mares (n = 8) were collected at an abattoir and processed histologically for evaluation of follicular clustering using the Morisita Index and follicular neighborhoods in ovarian sections. Young mares were found to have a large number of preantral follicles with neighbors (n = 2,626), while old mares had a small number (n = 305). Moreover, young mares had a higher number of neighbors per follicle (2.6 ± 0.0) than old mares (1.2 ± 0.1). Follicle clustering was shown to be present in all areas of the ovary, with young mares having more clustering overall than old mares and a tendency for higher clustering in the ventral region when ages were combined. Furthermore, follicles with neighbors were more likely to be morphologically normal (76.5 ± 6.5%) than abnormal (23.5 ± 6.5%). Additionally, morphologically normal activated follicles had increased odds of having neighbors than normal resting follicles, and these normal activated follicles had more neighbors (2.6 ± 0.1) than normal resting follicles (2.3 ± 0.1 neighbors). In the present study, it was demonstrated that preantral follicles do crowd in the mare ovary and that clustering/neighborhood patterns are dynamic and differ depending on mare age, follicular morphology, and follicular developmental stage.
Topics: Animals; Cluster Analysis; Female; Horses; Ovarian Follicle; Ovary
PubMed: 36194590
DOI: 10.1371/journal.pone.0275396 -
Naunyn-Schmiedeberg's Archives of... Feb 2021Caffeine consumption increases during early adulthood, which has adverse effects on the reproductive system. This study aimed to assess the impact of embryonic caffeine...
Caffeine consumption increases during early adulthood, which has adverse effects on the reproductive system. This study aimed to assess the impact of embryonic caffeine exposure on rat ovary in adulthood. Female Wistar rats (240-270 g) were divided into 5 groups (n = 7): experimental groups were exposed to 26, 45, 100, and 150 mg/kg of caffeine via drinking water during pregnancy and the control group only received drinking water. The ovaries of the offspring were taken out on days 7, 14, 28, 60, 90, and 120 of postnatal development, and then, they were fixed in 10% formaldehyde solution. Ovarian follicles were studied using stereological methods, and data were analyzed using one-way ANOVA followed by the Tukey test in SPSS software. A value of p < 0.05 was considered significant. The body weight, the weight of the ovaries, the ovarian volume, and the number of primordial follicles decreased significantly (p < 0.05) in 45 and 100 mg/kg, and (p < 0.001) in 150 mg/kg caffeine-treated groups at all stages of postnatal development. Significant decreases were observed in the number of primary and secondary follicles in 45 and 100 mg/kg (p < 0.05) and (p < 0.001) in 150 mg/kg caffeine-treated groups on days 7, 14, 28, and 60 compared to the control group. The number of Graafian follicles also decreased significantly (p < 0.001) in 45, 100, and 150 mg/kg caffeine-treated groups on days 14 and 28. Moreover, the mean volume of the oocyte in Graafian follicles reduced considerably in 45, 100, and 150 mg/kg caffeine-treated groups compared to other groups (p < 0.05). The thickness of the zona pellucida (ZP) in the secondary follicles (p < 0.02) and Graafian follicles (p < 0.05) showed a significant reduction in 100 and 150 mg/kg caffeine-treated groups on the 14th, 28th, and 60th days. In conclusion, high-dose caffeine consumption during gestation affects all stages of ovarian follicle development in rat offspring.
Topics: Animals; Caffeine; Female; Maternal-Fetal Exchange; Organ Size; Ovary; Pregnancy; Rats, Wistar; Rats
PubMed: 33128590
DOI: 10.1007/s00210-020-02008-8 -
Poultry Science Aug 2021Chicken ovaries are known to develop asymmetrically and only the left ovary fully develops. Although both have been greatly investigated, a gap in scientific reports is...
Chicken ovaries are known to develop asymmetrically and only the left ovary fully develops. Although both have been greatly investigated, a gap in scientific reports is still felt between 2-mo-old and sexual maturity. In this study, we aimed at investigating the changes in components that occur during growth to analyze the morphohistological correlation between the left ovary and the follicle development at different age stages in Gallus domesticus. The ovaries were harvested from 60 chickens aged 1 and 3-wk-old, 1, 2, 3, and 4-mo-old (n = 10 per age group), then fixed in AAF solution. Hematoxylin-and Eosin protocol was used to stain the tissue for microscopic observations. Results revealed that the left ovary exhibited an ovarian tissue, a site of follicular growth that displayed various shapes from smooth to greatly indented as the follicles differentiated. Atretic follicles at various regression stages were noticed frequently as the chicks grew in age from 3-wk-old onward along with their differentiation. Rete ovarii, remnants from the male homologs were observed throughout the whole study showing epoöphoron, connecting rete, and gland-like structures that tend to diminish with age. The feature of the left ovary is closely related to the follicular developmental stage, and the bigger and differentiated the follicles are, the more indented and irregular its epithelium appears. Atresia is a normal physiological process that we observed throughout the whole study. Also that, rete ovarii do not spontaneously arise in the ovary but it develops and grows in juvenile chicken as well as in adult ones.
Topics: Animals; Chickens; Female; Follicular Phase; Growth and Development; Male; Ovarian Follicle; Ovary
PubMed: 34242943
DOI: 10.1016/j.psj.2021.101191 -
Maturitas Nov 2015The regenerative potential of the mammalian ovary has been a controversial area over the last decade. Isolation of cells, termed oogonial stem cells (OSCs), from adult... (Review)
Review
The regenerative potential of the mammalian ovary has been a controversial area over the last decade. Isolation of cells, termed oogonial stem cells (OSCs), from adult rodent and human ovaries has been reported, with these cells exhibiting both germ and stem cell markers in culture. When re-introduced into an ovarian somatic environment these cells have generated follicles capable of producing healthy offspring in rodents, and there is some evidence of human OSCs being able to form oocyte-like structures in a xenotransplant model. Importantly, there are no data on their potential physiological role within the ovary, and specifically no evidence that they contribute to the primordial follicle pool and thus to later stages of follicle development. The cues required for oocyte differentiation from these cells are not well understood either in vivo or in vitro, and these will need to be further elucidated to maximise their potential for therapeutic intervention. OSCs may also be of value as a model to investigate normal human germ cell differentiation. It is likely that their interactions with ovarian somatic cells and/or extracellular signals will be important in these processes. This review summarises our current knowledge on the isolation and characterisation of mammalian oogonial stem cells.
Topics: Adult Stem Cells; Animals; Cell Differentiation; Female; Humans; Oocytes; Oogenesis; Ovarian Follicle; Ovary
PubMed: 26278874
DOI: 10.1016/j.maturitas.2015.07.017 -
International Journal of Molecular... Oct 2020Due to improvements in chemotherapeutic agents, cancer treatment efficacy and cancer patient survival rates have greatly improved, but unfortunately gonadal damage... (Review)
Review
Due to improvements in chemotherapeutic agents, cancer treatment efficacy and cancer patient survival rates have greatly improved, but unfortunately gonadal damage remains a major complication. Gonadotoxic chemotherapy, including alkylating agents during reproductive age, can lead to iatrogenic premature ovarian insufficiency (POI), and loss of fertility. In recent years, the demand for fertility preservation has increased dramatically among female cancer patients. Currently, embryo and oocyte cryopreservation are the only established options for fertility preservation in women. However, there is growing evidence for other experimental techniques including ovarian tissue cryopreservation, oocyte in vitro maturation, artificial ovaries, stem cell technologies, and ovarian suppression. To prevent fertility loss in women with cancer, individualized fertility preservation options including established and experimental techniques that take into consideration the patient's age, marital status, chemotherapy regimen, and the possibility of treatment delay should be provided. In addition, effective multidisciplinary oncofertility strategies that involve a highly skilled and experienced oncofertility team consisting of medical oncologists, gynecologists, reproductive biologists, surgical oncologists, patient care coordinators, and research scientists are necessary to provide cancer patients with high-quality care.
Topics: Antineoplastic Agents; Artificial Organs; Cryopreservation; Embryo, Mammalian; Female; Fertility Preservation; Humans; In Vitro Oocyte Maturation Techniques; Oocytes; Ovary; Pregnancy; Primary Ovarian Insufficiency
PubMed: 33096794
DOI: 10.3390/ijms21207792