The effect of temperature on the viability of superfemales in Drosophila melanogaster

Abstract

The superfemale is an individual having three X-chromosomes and two sets of autosomes. It has also many external characteristics by means of which it can be easily distinguished both from the normal sexes and from other sexual forms, i.e., intersexes and supermales. The superfemales arise in several kinds of genetical experiments concerned with abnormal chromosomal situations, such as in the progeny of the attached X-chromosome female, of the triploid female and in cases of non-disjunction of the X-chromosomes. But the frequency of superfemales found in cultured is always very much below that which might be expected theoretically on the basis of a knowledge of the genetic situation in a given case. Therefore, the superfemale can be considered as a typical semilethal form, which only relatively rarely reaches the imago stage.