Differential expression of Notch component and effector genes during ovarian follicle and corpus luteum development during the oestrous cycle.

Ovarian dynamics throughout the female oestrous cycle (EC) are characterised by cyclical follicle and corpus luteum (CL) development. These events are tightly regulated, involving extensive cell-to-cell communication. Notch is an evolutionarily well conserved cell-signalling pathway implicated in cell-fate decisions in several tissues. Here, we evaluated the extra-vascular expression patterns of Notch component and effector genes during follicle and CL development throughout the EC. Five mature CD1 female mice were killed at each EC stage. Blood samples were collected for progesterone measurement, ovaries were processed for immunohistochemistry and expression patterns of Notch components (Notch1, 2 and 3, Jagged1 and Delta-like1 and 4) and effectors (Hes1, Hes2 and Hes5) were characterised. Nuclear detection of Notch effectors indicates that Notch signalling is active in the ovary. Notch components and effectors are differentially expressed during follicle and CL development throughout the EC. The spatial and temporal specific expression patterns are associated with follicle growth, selection and ovulation or atresia and CL development and regression.