Optimized amplification and single-cell analysis identify GnRH-mediated activation of Rap1b in primary rat gonadotropes

► Optimized RNA amplification allowed microarray analysis of GnRH-stimulated gonadotrope-enriched primary pituitary cultures. ► rap1b is a novel early gene induced by GnRH in primary gonadotropes. ► Single-cell real-time PCR demonstrated that rap1b is induced by GnRH in the gonadotropes. ► Rap1b protein was markedly increased in GnRH-stimulated primary gonadotropes.