DNA DISTRIBUTION IN SPERMATID NUCLEI OF NORMAL AND SEGREGATION DISTORTER MALES OF DROSOPHILA MELANOGASTER

E. Hauschteck-Jungen ¹ and D. L. Hartl ²

¹ Strahlenbiologisches Institut der Univ. Zurich August Forel-Str. 7 8029 Zurich, Switzerland
² Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907

Using the DNA-specific dye BAO [2,5-bis-(4'-aminophenyl-(1')]-1,3,4-oxadiazol), we have examined spermiogenesis in wild-type males of Drosophila melanogaster and in males carrying various combinations of the Sd and Rsp mutations involved in segregation distortion. Wild-type strains, even those newly collected from nature, are heterogeneous with respect to the incidence of spermiogenic abnormalities, principally in having a variable number of spermatid nuclei per cyst that fail to undergo complete elongation. Among segregation distorter males, Rsp/Rsp homozygotes have the greatest incidence of nuclear nonelongation or incomplete elongation, Rsp/Rsp ⁺ heterozygotes are intermediate, while Rsp⁺/ Rsp⁺ homozygotes have the least amount of abnormality. Indeed, Sd Rsp⁺/Sd⁺Rsp⁺ males have significantly fewer spermiogenic aberrations than do wild-type strains.