Defective nuclear transport: a prime suspect in segregation distortion

Abstract

Segregation Distorter (SD) is an example of a meiotic drive system in Drosophila melanogaster, so designated because the SD locus is transmitted to virtually 100% of the progeny from a heterozygous male. Distortion occurs owing to abortive development of spermatids carrying the wild-type allele (SD+). A second locus, called Responder (Rsp), comprising heterochromatic repeat elements, is the target of Sd. A sensitive Rsp (Rsps) allele generally present on SD+ chromosomes renders the chromosome susceptible to distortion. SD chromosomes carry an insensitive Rsp (Rspi) allele and are resistant, therefore, to Sd-induced distortion.