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126 Regulation of initiation of follicle growth and dynamics of early follicular development in the sheep
- Source :
- Journal of Animal Science, Journal of Animal Science, American Society of Animal Science, 2018, 96 (suppl.S3), pp.343-344. ⟨10.1093/jas/sky404.757⟩, Journal of Animal Science, 2018, 96 (suppl.S3), pp.343-344. ⟨10.1093/jas/sky404.757⟩
- Publication Year :
- 2018
- Publisher :
- HAL CCSD, 2018.
-
Abstract
- Notice à reprendre pas de clé UT au 14 Janvier 2018; International audience; Primordial follicles embedded in the ovarian cortex are the source of developing follicles. Follicle growth activationand development up to the small antral follicle stage are controlled by cell interactions. The sheep ovary offersan appropriate non-rodent model to study these interactions, thanks to the development of in vitro and in vivoexperimental approaches, ex vivo molecular analyses and in silico mathematical modeling. Each primordial follicle, composed of an oocyte surrounded by a single layer of quiescent granulosa cells, relies on nutrients and growth factors supplied by the surrounding stroma of connective tissue. In vitro cultures of ovarian cortex have shown that primordial follicles are activated by the lifting of mechanisms maintaining quiescence, some of them involving AMH secreted by already growing follicles. Afterwards, follicle development is supported by a finely tuned molecular dialog between the growing oocyte and proliferating granulosa cells. The isolation of preantral follicles and their development in vitro as individual follicles perturb this dialog, leading to an acceleration of follicular maturation. In vivo, mutations in the oocyte factors BMP15, GDF9 or their receptor BMPR1B also impair this dialog, leading to an imbalance between oocyte growth and cell proliferation, which can be reproduced by models for cell dynamics. During the growth of preantral follicles, the recruitment and differentiation of theca cells from the ovarian stroma provide them with a structural and vascularized support. In vivo exposure of sheep fetalovaries to testosterone imprints the stroma cells so that the expression of genes involved in extracellular matrixorganization and cell-cell adhesion is affected in theca at adulthood; this leads to a lower ovarian tissue rigiditythat can account for the accelerated follicle growth observed in androgenized ewes. A better knowledge ofcell interactions during early follicular development will help to improve the biotechnology methods of fertilitypreservation.
- Subjects :
- endocrine system
[SDV.OT]Life Sciences [q-bio]/Other [q-bio.OT]
Ovarian Cortex
General Medicine
Biology
Oocyte
Antral follicle
follicle
Cell biology
Abstracts
Follicle
medicine.anatomical_structure
Theca
Follicular phase
Genetics
medicine
Animal Science and Zoology
ovary
Folliculogenesis
oocyte
Food Science
Extracellular matrix organization
Subjects
Details
- Language :
- English
- ISSN :
- 00218812 and 15253163
- Database :
- OpenAIRE
- Journal :
- Journal of Animal Science, Journal of Animal Science, American Society of Animal Science, 2018, 96 (suppl.S3), pp.343-344. ⟨10.1093/jas/sky404.757⟩, Journal of Animal Science, 2018, 96 (suppl.S3), pp.343-344. ⟨10.1093/jas/sky404.757⟩
- Accession number :
- edsair.doi.dedup.....4c31155fb7517bd6a31cf9c1b2f43b35