Abstract
Development of the germline cells of P-M dysgenic hybrids causing Gonadal (GD) sterility in Drosophila melanogaster was analyzed using light and electron microscopes. The first indication of an abnormality appeared in pole cells (primordial germ cells) during migration to gonadal mesoderm 5 to 6hr at 29°C. This stage corresponds to the initial stage of the temperature sensitivity of GD sterility. Necrosis of primordial germ cells was prominent in the gonads at the first instar when the primordial germ cells undergo exponential mitotic proliferation in normal larvae. About 10% of primordial germ cells degenerated in nearly all the gonads of the first instar larvae which would normally develop into fertile flies at 25°C.
