A comparative study of induced increases in proximal recombination in Drosophila melanogaster females.

Abstract

Crossing over was studied in Drosophila melanogaster females between f – car – bb1– Dp(y+) on the X chromosome. Mitomycin C and γ-rays increased crossing over in all three regions, increased nondisjunction and affected meiotic as well as gonial cells. Temperature was recombinagenic only in the car – bb1regions and the autosomal inversions Cy and Ubx130increased crossing over in both regions containing euchromatin (f – car and car – bb1). Actino-mycin D-treatment resulted in a slight decrease in crossing over. The data indicate that there may be two general classes of recombinagens, those that affect crossing over in proximal euchromatin and those which in addition, induce breaks in heterochromatin.