PRELIMINARY CHARACTERIZATION OF "SEX RATIO" AND REDISCOVERY AND REINTERPRETATION OF "MALE SEX RATIO" IN DROSOPHILA AFFINIS

[摘要] In D. affinis "sex ratio" ( sr ), a form of meiotic drive characterized by the production of mostly or only female progeny by certain males, is associated with two different X chromosome sequences, XS-I XL-II and XS-II XL-IV. The behavior of the two sequences differed, depending on the Y chromosome constitution, being either Y L or 0. Males with sequence XS-II XL-IV and Y L produced progenies with nearly normal sex ratios; males with the same X chromosome sequence but in the absence of a Y chromosome in some cases gave progenies with nearly normal sex ratios but in other cases gave progenies which tended toward phenotypic sr . Males with sequence XS-I XL-II and Y L gave progenies which were characteristically sr (0.97–0.98 females); in the absence of a Y chromosome males with this sequence produced progenies which were virtually all-male. This latter finding is presumably identical to Novitski's (1947) "male sex ratio" ( msr ). The interpretation offered here attributes msr to an interaction between sr sequence XS-I XL-II and the 0 condition. A general consideration of the available data on sr in D. affinis is presented.

[学科分类] 医学（综合）