9408473 Abstract The long term goal of these studies is to elucidate the genetic and molecular structure of segregation distortion (SD) chromosomes, their mechanism of action and their evolutionary origin. The immediate aims are to (1) molecularly characterize Sd and its products, (2) isolate and analyze null mutations of Sd+, (3) cytogenetically enolase M(SD), an upward modifier of distortion and Su(SD), a strong X-linked suppressor of distortion. %%% Segregation Distorter (SD) is a naturally occurring meiotic drive system on the second chromosome of Drosophila melanogaster with the property that heterozygous SD/SD+ males transmit the SD chromosome to their offspring in vast excess over the normal homolog. The basis of this distorted transmission is the dysfunction of spermatids that receive the SD+ chromosome. Dysfunction of these spermatids is associated with a failure of chromatin condensation in the nuclei but the underlying molecular mechanisms are unknown. The long term goal of these studies is to elucidate the genetic and molecular structure of SD chromosomes. ***
