You are studying three autosomal recessive mutations in a Mongonian fly that is
ID: 6702 • Letter: Y
Question
You are studying three autosomal recessive mutations in a Mongonian fly that is reminiscent of Drosophila here on Earth. Flies that are homozygous for the rd mutation are red-winged, those that are homozygous for the bl mutation are blind, and those that are homozygous for st mutation are straight-legged. Wildtype flies are blue-winged, not-blind, and bowed-legged.You mate flies from two true-breeding strains, and the resulting F1 flies are all blue-winged, not-blind, and bowed-legged. F1 females are then mated to males that are red-winged, blind, and straight-legged. In the F2 generation, among the 1000 progeny resulting from this cross, you observe the following phenotypes.
red-winged, blind, and straight-legged 26 flies
red-winged, blind, and bowed-legged 455 flies
red-winged, not-blind, and bowed-legged 24 flies
blue-winged, blind, and straight-legged 27 flies
blue-winged, blind, and bowed-legged 4 flies
blue-winged, not-blind, and straight-legged 442 flies
blue-winged, not-blind, and bowed-legged 22 flies
(a) The male flies that were bred to the F1 generation in order to produce the F2 generation were red-winged, blind, and straight-legged. On each of their chromosomes, they have the alleles rd-, bl-, and st-. Using this notation, state the genotype of each of the two true-breeding parental strains.
(b) Draw a genetic map of the three loci. Show all your calculations and indicate if any chromosomal interference is observed.