In the haplodiploid insect order Hymenoptera, males are derived from haploid unfertilized eggs and females from fertilized diploid eggs. In the August 22
Beye et al. identified genetic markers that flanked the sex-determining locus and by chromosome walking and fine mapping located a single gene that was always heterozygous in females. The ~5-kb region containing it was cloned, sequenced, and analyzed for exon-coding regions. These were assembled into the...