Molecular determinants of a competent bovine corpus luteum: first- vs final-wave dominant follicles

Gregson, Emma; Webb, Robert; Sheldrick, Elizabeth L.; Campbell, Bruce K.; Mann, George E.; Liddell, Susan; Sinclair, Kevin D.

Abstract

Reproductive management in cattle requires the synchrony of follicle development and oestrus before insemination. However, ovulation of follicles that have not undergone normal physiological maturation can lead to suboptimal luteal function. Here, we investigated the expression of a targeted set of 47 genes in (a) a first-wave vs final-wave dominant follicle (DF; the latter destined to ovulate spontaneously) and (b) 6-day-old corpora lutea (CLs) following either spontaneous ovulation or induced ovulation of a first-wave DF to ascertain their functional significance for competent CL development. Both the mass and progesterone-synthesising capacity of a CL formed following induced ovulation of a first-wave DF were impaired. These impaired CLs had reduced expression of steroidogenic enzymes (e.g. STAR and HSD3B1), luteotrophic receptors (LHCGR) and angiogenic regulators (e.g. VEGFA) and increased expression of BMP2 (linked to luteolysis). Relative to final-wave DFs, characteristic features of first-wave DFs included reduced oestradiol concentrations and a reduced oestradiol:progesterone ratio in the face of increased expression of key steroidogenic enzymes (i.e. CYP11A1, HSD3B1 and CYP19A1) in granulosa cells and reduced expression of the HDL receptor SCARB1 in thecal cells. Transcripts for further components of the TGF and IGF systems (e.g. INHA, INHBA, IGF2R and IGFBP2) varied between the first- and final-wave DFs. These results highlight the importance of hormones such as progesterone interacting with local components of both the TGF and IGF systems to affect the maturation of the ovulatory follicle and functional competency of the subsequent CL.

Citation

Gregson, E., Webb, R., Sheldrick, E. L., Campbell, B. K., Mann, G. E., Liddell, S., & Sinclair, K. D. (2016). Molecular determinants of a competent bovine corpus luteum: first- vs final-wave dominant follicles. Reproduction, 151(6), 563-575. https://doi.org/10.1530/REP-15-0415

• Journal Article Type: Article
• Acceptance Date: Mar 3, 2016
• Online Publication Date: Jun 1, 2016
• Publication Date: Jun 1, 2016
• Deposit Date: Nov 4, 2016
• Publicly Available Date: Nov 4, 2016
• Journal: Reproduction
• Print ISSN: 1470-1626
• Electronic ISSN: 1741-7899
• Publisher: BioScientifica
• Peer Reviewed: Peer Reviewed
• Volume: 151
• Issue: 6
• Pages: 563-575
• DOI: https://doi.org/10.1530/REP-15-0415
• Public URL: https://nottingham-repository.worktribe.com/output/787016
• Publisher URL: https://rep.bioscientifica.com/view/journals/rep/151/6/563.xml
• Additional Information: Disclaimer: this is not the definitive version of record of this article. This manuscript has been accepted for publication in Reproduction, but the version presented here has not yet been copy-edited, formatted or proofed. Consequently, Bioscientifica accepts no responsibility for any errors or omissions it may contain. The definitive version is now freely available at http://dx.doi.org/10.1530/REP-15-0415. 2016.
• Contract Date: Nov 4, 2016