X-chromosome involvement in male hybrid sterility from glossina morsitans sub-species crosses

Abstract

Crosses between sub-species of the tsetse fly Glossina morsitans yield males which can mate but are unable to inseminate. To test the hypothesis of Xchromosome involvement in this form of male sterility, G. m. morsitans carrying the X-chromosome marker ocra were mated to wild type G. m. centralis, and the F1 females backcrossed to each parental population. The ocra gene was used to distinguish those male progeny which had inherited their X-chromosomes from each sub-species and these categories of male from each backcross differed significantly in the proportion which could inseminate. It is concluded that inability to inseminate is caused by an interaction of the X-chromosome from one sub-species with the Y-chromosome and/or autosomal factors from the other. The results are discussed in relation to similar observations from crosses within two Anopheles species complexes and to the genetic control of tsetse flies. © 1980 The Genetical Society of Great Britain.