A particular Drosophila female that is wild-type in appearance is known to be heterozygous for the three recessive mutations black body (b), curved wings (c) and purple eyes (p). When this female is testcrossed, the following progeny result:
Black body, purple eyes – 27
Curved wings -23
Black body, curved wings – 361
Purple eyes -379
Black body – 92
Curved wings, purple eyes – 108
Wild type – 6
Black body, curved wings, purple eyes – 4
a. Determine the order of these three genes on chromosome 2 of Drosophila. Diagram the allelic arrangement of these three genes on the two homologs carried by the heterozygous female used in this testcross. Indicate the correct gene order.
b. Determine the map distances between these loci. Show your calculations.
c. Determine an interference value for this genetic interval. Show your calculations.