Granulosa Cell Exposure to Excess Androgens Inhibits Their Ability to Proliferate in the Cow Which May Cause or Perpetuate Androgen Excess

Within the UNL physiology herd, a group of cows have been identified with excess androgen (androstenedione, A4) in their dominant follicle (30 fold higher than controls) and a 17% reduction in calving rate, suggesting subfertility. Th e objective was to identify altered granulosa cell gene expression that could be preventing these cells from converting excess androgen into estrogen. Microarray analysis suggests these granulosa cells experience inhibited proliferation resulting in a reduced total population of cells. Improved understanding of the causes of this phenotype may provide beef producers with tools to identify potentially subfertile cattle and improve reproductive efficiency