CYTOLOGY OF A GENETIC SEXING SYSTEM IN ANOPHELES ALBIMANUS

Abstract

Several translocation and translocation-inversion strains were induced in Anopheles albimanus Wiedemann by using X and gamma irradiation. The propoxur resistance allele (prr), located on chromosome arm 2R, was used to screen for T(Y;2R) translocations and In(2R) inversions. Six T(Y;2R) translocations and eight In(2R) inversions are described herein. The strains designated In(2R)[T(Y:2R)3]2 and In(2R)[T(Y;2R)6]4 eliminated 99.8% and 99.7%, respectvely, of the crossing over between the translocation breakpoint and the prr locus. A direct correlation is shown between genetic map units and physical distance (micrometers) of the polytene chromosome. Inversions are shown to eliminate recombinants in excess of the expected value based on physical size of the aberration. The Y chromosome, which is heterochromatic and located in the chromocenter in polytene complements, is visible in two terminal translocations.