Abstract
Linkage analysis of kdr (knockdown resistance), the pyrethroid- and DDT-resistance gene, was conducted by performing a series of crosses involving marker genes for each chromosome. The kdr gene assorted independently of the organophosphate-resistance gene Est-2, a marker for the 3rd chromosome, and of the sex-determining factor m, a marker for the 1st chromosome. The 2nd chromosome marker gene y, yellow larva, and kdr were found to be 35 ± 4 map units apart. A 3-point cross with ru (ruby eye), y, and kdr established the gene order as kdr-ru-y.