Polymorphism of the follicle stimulating hormone receptor does not impact reproductive performance or in-vitro embryo production in beef heifers

Authors: Snider, Alexandria - Alex; Yake, Hannah; GRANGER, CAMRYN - South Dakota State University; ROSASCO, SHELBY - New Mexico State University; McDaneld, Tara; Snelling, Warren; CHASE, CHADWICK - Retired ARS Employee; Miles, Jeremy; Lents, Clay; QUAIL, LACEY - Texas A&M Agrilife; RICH, JERICA - Arkansas State University; EPPERSON, KAITLIN - Texas A&M Agrilife; Crouse, Matthew; SUMMERS, ADAM - New Mexico State University; PERRY, GEORGE - Texas A&M Agrilife; Bennett, Gary; Cushman, Robert - Bob

Submitted to: Theriogenology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2022
Publication Date: 10/22/2022
Citation: Snider, A.P., Yake, H.K., Granger, C.D., Rosasco, S.L., McDaneld, T.G., Snelling, W.M., Chase Jr., C.C., Miles, J.R., Lents, C.A., Quail, L.K., Rich, J.J., Epperson, K.M., Crouse, M.S., Summers, A.F., Perry, G.A., Bennett, G.L., Cushman, R.A. 2023. Polymorphism of the follicle stimulating hormone receptor does not impact reproductive performance or in-vitro embryo production in beef heifers. Theriogenology. 195:131-137. https://doi.org/10.1016/j.theriogenology.2022.10.025.
DOI: https://doi.org/10.1016/j.theriogenology.2022.10.025

Interpretive Summary: Follicle stimulating hormone (FSH) is a key regulator for developing ovarian follicles, leading to ovulation of an oocyte for potential fertilization. This hormone is also used in assisted reproductive technologies, such as superovulation for embryo collection. Recently, it has been shown a single nucleotide polymorphism (SNP) on the receptor for FSH (FSHR) can impact embryo quality during a superovulation protocol. The current study examined three different SNP polymorphisms on the c.377C>G FSHR to determine impacts on in-vitro embryo production. Embryonic development rates during in-vitro development were not different between FSHR SNP polymorphisms. This information provides some insight that the FSHR polymorphism does not appear to influence in-vitro embryonic development and may not be a selecting criteria for females undergoing oocyte collections.

Technical Abstract: Assisted reproductive technologies are used to propagate desirable genetics in a shortened timeframe. Selected females undergo ovarian stimulation with the use of follicle stimulating hormone (FSH) to increase embryo recovery for subsequent transfer programs. The FSH receptor (FSHR) c.337 C>G variant was reported to have a reduction in viable embryo numbers in an ovarian stimulation protocol. We, therefore, hypothesized that FSHR c.337 C>G would result in reduced in-vitro blastocyst development. Beef heifers were genotyped and selected based on the c.337 C>G FSHR genotype (CC, CG, GG; n = 15-16/genotype). Estrus was synchronized with a Select Synch protocol and heifers were slaughtered 5 days after induced ovulation. Anterior pituitaries, serum and reproductive tracts were collected at slaughter for analysis. Cumulus oocyte complexes (COCs) were collected and pooled within genotype for in-vitro fertilization (IVF) and subsequent blastocyst development. No differences were observed in carcass weights, anterior pituitary weights, serum progesterone, corpus lutea weight, surface follicle counts, histological follicle counts or follicular fluid estradiol concentration (P > 0.1) due to FSHR genotype. Differences were observed for ovulation rates in the GG FSHR genotype group (P < 0.01). However, cleavage and blastocyst rates were not affected due to FSHR genotype (P > 0.1), following standard IVF protocols. The FSHR variant does not influence antral follicle counts, estradiol production, or in-vitro blastocyst development in beef heifers. The GG FSHR genotype had an increased ovulation rate, which may indicate a greater potential for twinning, but research with a larger population is warranted to support this hypothesis.