In Drosophila, the recessive dp allele of the dumpy geneproduces short, curved wings, while the recessive allele bw of thebrown gene causes brown eyes. In a testcross using femalesheterozygous for both of these genes, the following results wereobtained:
wild-type wings, wild-type eyes 178
wild-type wings, brown eyes 185
dumpy wings, wild-type eyes 172
dumpy wings, brown eyes 181
In a testcross using males heterozygous for both of these genes,a different set of results was obtained:
wild-type wings, wild-type eyes 247
dumpy wings, brown eyes 242
a. What can you conclude from the first testcross?
b. What can you conclude from the second testcross?
c. How can you reconcile the data shown in parts a and b ? Canyou exploit the difference between these two sets of data to devisea general test for synteny in Drosophila?
d. The genetic distance between dumpy and brown is 91.5 m.u. Howcould this value be measured?
