Progeny (male and female) of homozygous females mated at 29^oC is often sterile due to absence of germ cells in the ovaries or testes.

Homozygous females normal in appearance. When oogenesis in such females proceeds at 28.5^oC 80-85% of the eggs cease development before the blastoderm stage. Most embryos reaching gastrulation continue development normally except for the frequent absence of pole cells; 11-15% of surviving adult progeny have agametic gonads; if the maternal females are also homozygous for an X-linked modifier, mod, the incidence of agametic survivors increases to 60-65%. Oogenesis at 10^oC leads to 62% hatch and 6-10% agametic, which is decreased to <3% in the presence of homozygous mod. Outcome not influenced by genotype of father. The temperature-sensitive period for survival of zygotes produced by mod gs females is monophasic extending from stages 9 to 14 of oocyte development, whereas that for agametic gonads is diphasic with one sensitive period at stages 6-7 and the other more severe period from stages 10-14; stages 7-9 temperature insensitive. The histology of agametic gonads of both males and females resemble those produced by ultra-violet irradiation of embryonic pole cells (Lauge, Sauphanov and Randrianandrianina, 1977).