Atretic ovarian follicles morphology and immunolocalization of active caspase-3 in algerian bedouin goat (capra hircus) ovaries

Abstract

This study aims to highlight the cellular and molecular events of atresia in the Bedouin goat ovarian follicles. Ovaries collected from slaughterhouses during breeding and non-breeding seasons were submitted to morphological studies and immunolocalization of active caspase-3. The results showed that ovaries were heavier (P<0.05) during the breeding season. The atresia occurred at all stages of follicular development in breeding and non-breeding seasons. At the preantral stage, degeneration affected primarily oocyte and active caspase-3 immunoreactivity was detected in the oocyte with a few staining in follicular cells. At the antral stage, atresia affected in first the granulosa layer cells which were characterized by an abnormal indentation of nuclei and positive active caspase-3 immunolabeling. At the early stage of atresia, the granulosa cells exhibited a few pycnotic nuclei and lost their cellular integrity, by getting scattered; these cells were positive to active caspase-3. At the late stage, the scattered cells invaded the antral cavity and the dead cells were eliminated by phagocytic cells. The oocyte seemed to undertake a long process of atresia via an autophagic pathway and it was the last to die. Finally, the follicle was replaced by a collagen fiber forming a scar of atresia. In conclusion, important morphological changes occurred in atretic follicles mainly in antral stage by apoptosis via caspase-3 signaling pathway, in breeding and non-breeding seasons.

Keywords

• atresia
• apoptosis
• active caspase-3
• breeding season
• non-breeding season
• bedouin goat