SUBTYPES OF ACTIVE CELL-DEATH IN THE GRANULOSA OF OVARIAN ATRETIC FOLLICLES IN THE QUAIL (COTURNIX-COTURNIX-JAPONICA)

Follicular atresia in the ovaries of Japanese quail was studied by cyt ochemistry and electron microscopy. Three different types of cell deat h coexisted in the granulosa. A large number of cells showed signs of apoptosis. The DNA fragmentation in these cells was demonstrated in a previous study using in situ end-labeling. A second and non-negligible type of cell death consisted of extensive autophagocytosis of the cyt oplasm occurring simultaneously with late nuclear alterations. Finally , a few detached cells displayed cytoplasmic disintegration and small irregular clumps of chromatin condensation indicative of primary cell necrosis. Apoptotic versus autophagic cell death revealed a different pattern of acid phosphatase activity (lysosomal versus cytoplasmic). W e propose that these observations may be linked to the existence of di stinct subpopulations in the granulosa as has been shown by others. Th is study confirms the biochemical data on granulosa cell death, but de monstrates that apoptosis is not the exclusive mode of active cell dea th in follicular atresia.