Impact of preovulatory follicle maturity on oocyte metabolism and embryo development.

Author

Hannah M. Clark, The University of Tennessee in KnxovilleFollow

Date of Award

5-2024

Degree Type

Thesis

Degree Name

Master of Science

Major

Animal Science

Major Professor

Sarah E. Moorey

Committee Members

J. Lannett Edwards, F. Neal Schrick

Abstract

Improved oocyte competence for embryo development and pregnancy was observed following ovulation of preovulatory follicles with greater physiological maturity prior to the gonadotropin releasing hormone (GnRH)-induced luteinizing hormone (LH) surge. It was hypothesized that follicular fluid from preovulatory follicles of greater physiological maturity better supports the maturing oocyte’s metabolic requirements and improves embryo development. The objective was to determine if differences in preovulatory follicular fluid due to follicle maturity influence oocyte metabolism during in vitro maturation (IVM) and improve embryo development. Bovine preovulatory follicular fluid was collected 18 h after a GnRH-induced LH surge. Serum estradiol concentration at GnRH administration categorized follicles as greater or lesser physiological maturity. Immature bovine oocytes were submitted to 24 h IVM in medium supplemented with 20% follicular fluid from preovulatory follicles of greater or lesser maturity. Embryo development was recorded. Oocyte maturation media and spent blastocyst media were submitted for metabolomics. A randomized block design was utilized to determine differences in embryo development and media metabolites (P < 0.05). Stage was less advanced in blastocysts from oocytes matured in greater versus lesser maturity follicular fluid treatment (P = 0.01), but cleavage and blastocyst development did not differ (P > 0.28). At the conclusion of 24 h IVM, abundance of 66 metabolites differed between greater and lesser follicle maturity treatments. Nine metabolites differed in spent blastocyst media. Results suggest improved amino acid, purine, and glucose metabolism, followed by an economically efficient rate of embryo development, in oocytes matured in greater versus lesser maturity follicular fluid.

Recommended Citation

Clark, Hannah M., "Impact of preovulatory follicle maturity on oocyte metabolism and embryo development.. " Master's Thesis, University of Tennessee, 2024.
https://trace.tennessee.edu/utk_gradthes/11339