Luteinizing Hormone Receptor (LHR): basic concepts in cattle and other mammals. A review

Acquisition of the luteinizing hormone receptor (LHR) on granulosa cells of the dominant follicle is essential to physiological LH-mediated effects on the final stages of follicular growth, final maturation of the oocyte, ovulation and luteinization of the follicular wall. Therefore, LHR plays a key role in the final maturation of the dominant follicle from follicular dominance to ovulation. In this review, the basic molecular aspects of LHR (gene structure, alternative splicing and ligand mediated activation) and the physiological regulatory aspects (changes in LHR expression during antral follicle growth and a post-transcriptional model for downregulation of LHR transcripts) are addressed. Despite the accumulation of considerable amounts of information about LHR, a comprehensive and broad model for the role of LHR in bovine antral follicle growth is missing. Questions such as the function for alternative LHR transcripts, their transcriptional and translational regulation, and how the transcripts go to the cell surface and interact with ligands remain to be elucidated in bovine and other species.