OVARIAN DEFECTS IN HYBRIDS OF THE SPECIES PAIR DROSOPHILA-VIRILIS ANDDROSOPHILA-TEXANA

In interspecific matings between Drosophila virilis and Drosophila tex ana female sterility is observed in F-2 hybrid females. A previous stu dy 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 fe males of the parental species are not able to develop upon maturity. W ith few exceptions, the hybrid ovaries remained alive in the host envi ronment, but their oocytes failed to develop to vitellogenic stages. T hus, in hybrid females between Drosophila virilis and Drosophila texan a sterility is the result of defects in both the two main developmenta l processes of egg maturation, the synthesis of vitellogenins in the f at body and the uptake of vitellogenins by the ovary. (C) 1997 Wiley-L iss, Inc.