Germ cell death in the degenerating right ovary of the chick embryo

The right ovary of chick embryos is known to degenerate during embryogenesis, while the left one advanced its normal growth. The present study demonstrates germ cell death in the degenerating right ovary. In the process of germ cell death, chromatin condensation, reduction of cell size, and formation of apoptotic bodies were observed. The cell organelles were almost normal in the early stages of the process. Fragments of broken germ cells were phagocytosed by neighboring cells or macrophages. From these observations, it may be assumed that germ cell death in the right ovary of chicks is related to apoptosis. In the normal left ovary, similar cell death was only observed in the germ cells in the medulla, but not in the cortex. Therefore, germ cell death seems to be a phenomenon common to the medullae of both the right and left ovaries.