Isolation of genes differentially expressed in dominant and subordinate bovine follicles.

In monoovulatory species such as cattle, unknown mechanisms lead to the selection of one of a cohort of developing ovarian follicles to assume dominance and continue to grow in each follicular wave. We have used suppressive subtraction hybridization to identify genes differentially expressed in the granulosa cells of dominant and subordinate follicles. Inhibin beta A, apolipoprotein E receptor 2, MAPK kinase kinase 5 (ask1), and carboxypeptidase D were isolated and verified to be reliable markers for dominant follicles using real-time RT-PCR.