CYTOLOGY AND GENETICS OF A PRONOTAL-WING TRAIT IN THE GERMAN COCKROACH

A new pronotal-win g mutant of the German cockroach, Blattella germanica (L.), has been described and studied. Morphologically, it is similar to previously described translocation proving traits (T(9, 10)Pw) in this species. Genetically it is inherited as an autosomal semidominant lethal with somewhat reduced viability especially through the males. Cytologically the trait is associated with a terminal deficiency of the ninth pair of meiotic chromosomes, and has been named Df(9)Pw. It is linked with the group VIII markers ru and st at average map distances of 3.4 and 1.5 units, respectively, thus allowing, for the first time, a positive linkage group-autosome correlation for the German cockroach. Comparative studies of the deficiency and translocation Pw traits have produced an approximation of translocation breakpoints and centromere location on autosomes 9 and 10, establishment of the relationship between the deficiency and the translocation, and a tentative assignment of specific traits to specific locations on chromosome 9. The genetic makeup of the prowing locus is also discussed.