Analysis of a Strong Suppressor of Segregation Distorter in .

() is a naturally occurring male meiotic drive system in , characterized by almost exclusive transmission of the chromosome owing to dysfunction of sperm receiving the homolog. Previous studies identified at least three closely linked loci on chromosome required for distortion: , the primary distorting gene; (), which increases the strength of distortion; and (), the apparent target of Strength of distortion is also influenced by linked upward modifiers including () and (), and by various unlinked suppressors. Although is known to encode a mutant RanGAP protein, none of the modifiers have been molecularly identified.