Ovarian defects in hybrids of the species pair Drosophila virilis and Drosophila texana.

ABSTRACT

In interspecific matings between Drosophila virilis and Drosophila texana female sterility is observed in F2 hybrid females. A previous study has shown that no vitellogenin synthesis occurs in the fat body of sterile hybrid females. The results presented in this paper show that hybrid ovaries of sterile females transplanted into the abdomens of females of the parental species are not able to develop upon maturity. With few exceptions, the hybrid ovaries remained alive in the host environment, but their oocytes failed to develop to vitellogenic stages. Thus, in hybrid females between Drosophila virilis and Drosophila texana sterility is the result of defects in both the two main developmental processes of egg maturation, the synthesis of vitellogenins in the fat body and the uptake of vitellogenins by the ovary.