Abstract Steroids and gonadotrophins are essential for the regulation of late stages of preantral development and antral follicular development. Although the luteinizing hormone receptor (LHCGR) has been detected in the preantral follicles of rats, rabbits, and pigs, its expression, in bovine fetal ovary, has not been demonstrated. Based on this, we aimed to investigate the expression of the LHCGR and LHCGR mRNA binding protein (LRBP), as well as, to quantify bta-miR-222 (a regulatory microRNA of the LHCGR gene) during the development of bovine fetal ovary. In summary, LHCGR expression was observed in the preantral follicle in bovine fetal ovary, from oogonias to primordial, primary and secondary stages, and the mRNA abundance was lower on day 150 than day 60. However, the mRNA abundance of LRBP followed the opposite pattern. Similar to LRBP, the abundance of bta-miR-222 was higher on day 150 than day 60 or 90 of gestation. The LHCGR protein was detected in oogonia, primordial, primary, and secondary follicles. Moreover, both oocytes and granulosa cells showed positive immunostaining for LHCGR. In conclusion, we suggest the involvement of LHCGR/LRBP/bta-mir222 with mechanisms related to the development of preantral follicles in cattle. (LHCGR rats rabbits pigs ovary demonstrated this , (LRBP) btamiR222 btamiR bta miR 222 bta-miR-22 a gene summary primordial 15 However pattern 6 9 gestation oogonia Moreover conclusion LHCGR/LRBP/btamir222 LHCGRLRBPbtamir222 LHCGRLRBPbtamir LHCGR/LRBP/bta mir222 mir LHCGR/LRBP/bta-mir22 cattle (LRBP btamiR22 22 bta-miR-2 1 btamir222 btamir LHCGR/LRBP/btamir22 LHCGRLRBPbtamir22 LHCGRLRBPbta mir22 LHCGR/LRBP/bta-mir2 btamiR2 2 bta-miR- btamir22 LHCGR/LRBP/btamir2 LHCGRLRBPbtamir2 mir2 LHCGR/LRBP/bta-mir bta-miR btamir2 LHCGR/LRBP/btamir

Abstract Lipid metabolism is essential for ensuring oocyte maturation and embryo development. β-Oxidized fatty acids (FA) are a potent source of energy for cells, particularly for bovine somatic follicular cells. Superstimulatory protocols using follicle stimulating hormone (FSH) or FSH combined with equine chorionic gonadotropin (eCG) are capable of stimulating the follicular microenvironment and drive the expression of biomarker genes associated with lipid metabolism in the cumulus-oocyte complex (COC) for better embryo development. In this study, we assesed the effects of FSH and FSH/eCG protocols on the expression of genes related to lipid metabolism in bovine granulosa cells (GCs). Further, we measured triglyceride levels in follicular fluid (FF) obtained from both superstimulatd and non-superstimulated cows (synchronized cows). In summary, superstimulation with gonadotropins maintained the TG levels in bovine FF and ensured GCs mRNA abundance of ACSL1, ACSL3, ACSL6, SCD, ELOVL5, ELOVL6, FASN, FADS2, and SREBP1. We, however, found the abundance of CPTIB mRNA to be lower in GCs obtained from cows subjected to FSH/eCG protocols than synchronized cows. In conclusion, the findings of this study showed that ovarian superstimulation around the preovulatory phase has a mild impact on the lipid metabolism in GCs. development βOxidized β Oxidized FA (FA (FSH eCG (eCG cumulusoocyte cumulus COC (COC FSHeCG . (GCs) Further (FF nonsuperstimulated non superstimulated cows) summary ACSL1 ACSL ACSL3 ACSL6 SCD ELOVL5 ELOVL ELOVL6 FASN FADS2 FADS SREBP1 SREBP We however conclusion (GCs