Sustained fertility from first-wave follicle oocytes that pause their growth
Year: 2024
Type: preprint
Abstract: Summary Ovulation results from the cyclical recruitment of non-renewing, quiescent oocytes for growth. Therefore, the primordial follicles that are established during development from an oocyte encapsulated by granulosa cells are thought to comprise the lifelong ovarian reserve 1–4 . However, using oocyte lineage tracing in mice, we observed that a subset of oocytes recruited for growth in the first juvenile wave remain paused for many months before continuing growth, ovulation, fertilization and development into healthy offspring. This small subset of genetically-labeled fetal oocytes, labeled with Sycp3-CreERT2, is distinguished by earlier entry and slower dynamics of meiotic prophase I. While labeled oocytes were initially found in both primordial follicles and growing follicles of the first wave, they disappeared from primordial follicles by puberty. Unexpectedly, these first-wave labeled growing oocytes persisted throughout reproductive lifespan and contributed to offspring at a steady rate beyond 12 months of age, suggesting that follicles can pause mid-growth for extended periods then successfully resume. These results challenge the conclusion from lineage tracing of granulosa cells that first-wave follicles make a limited contribution to fertility 5 and furthermore suggest that growth-paused oocytes comprise a second and previously unrecognized ovarian reserve.
Institutions: University of California, San Francisco, Cornell University
Language: English
Field: Medicine
Domain: Health Sciences
Open Access status: green
Awards: Assessing transgenerational effects of Phthalates on primordial germ cells, Interrogating the Role of HSF1 in Ovarian Stress, The Role and Branching Dynamics of Sympathetic Nerves in Ovarian Folliculogenesis, Cell competition in the developing mouse germline, Glucocorticoid Signaling and Stress in the Developing Mammalian Germline, Fmr1 Function and Repeat Expansion in the Developing Germline, Predoctoral Training in Developmental Biology, Regulation of MutL-gamma function in mediating crossing over in mammalian meiosis
OpenAlex ID: W4402025373