243 Relationship Among Granulosa Cell Gnrh-i, -II, and Receptor Mrna Abundance and Follicular Fluid Steroid Hormone Concentrations of Bovine Antral Follicles at Specific Stages of Follicular Development Academic Article uri icon

abstract

  • Abstract Transcript abundance of two forms of GnRH and its receptor have been characterized in bovine ovaries. The objective was to investigate the relationship of GnRH-1, GnRH-2, GnRH-R, intrafollicular estradiol (E2) and progesterone (P4) during follicular development. Ovaries were collected from beef cows at specific stages of follicular development [pre-selection (PRE, n = 9), post-selection (POST, n = 9), and post-selection 24h after luteal regression (PG, n = 9)]. The largest follicle per stage was aspirated to obtain granulosa cells (GC) and follicular fluid (FF). Total cellular RNA was extracted from GC and RT-PCR was performed for GnRH-1, GnRH-2, GnRH-R and GAPDH. Radioimmunoassays were performed to determine FF concentrations of E2 and P4. Data were analyzed using the MIXED and REG procedures in SAS. There was no difference (P ≥ 0.23) in mRNA abundance of GnRH-2, GnRH-R or FF concentrations of P4 across follicular stages. There was an effect of stage on FF E2 (PRE: 17,925±20,273, POST: 28,458±21,503, and PG: 252,616±21,503 pg/mL; P > 0.01). Stage affected GnRH-1 mRNA abundance (PRE: 2.28±0.55, POST: 0.92±0.55, and PG: 0.11±0.55; P = 0.03). There was no relationship of GnRH-1 and GnRH-2 mRNA abundance or effect of FF P4 on GnRH-R mRNA abundance (P ≥ 0.23). There was no effect of FF P4 on GnRH-1 mRNA abundance (P = 0.68). There was no effect of FF E2 on GnRH-2 mRNA abundance (P = 0.66). As FF E2 increased GnRH-R mRNA abundance tended to increase (P = 0.10;r2=0.13). As FF P4 concentrations increased GnRH-2 mRNA abundance tended to decrease (P = 0.09;r2=0.12). As FF E2 increased GnRH-1 mRNA abundance decreased (P = 0.02;r2=0.20). In conclusion, there were differences in peptide and receptor mRNA abundance of GnRH in relation to FF E2 and P4 at specific stages of follicular development. This is supportive of a regulatory relationship between ovarian GnRH and steroidogenesis. This work is supported by AFRI Grant No.2018-67016-27578 from USDA. USDA is an equal opportunity provider and employer.

published proceedings

  • Journal of Animal Science

author list (cited authors)

  • Rich, J. J., Northrop-Albrecht, E. J., Epperson, K. M., Zoca, S. M., Perkins, S. D., Daly, R. F., Cushman, R. A., & Perry, G. A.

citation count

  • 0

complete list of authors

  • Rich, Jerica J||Northrop-Albrecht, Emmalee J||Epperson, Kaitlin M||Zoca, Saulo Menegatti||Perkins, Stephanie D||Daly, Russell F||Cushman, Robert A||Perry, George A

publication date

  • October 2021