Question

you have stumbled on a new species of fly (order diptera), and being a geneticist, you have already identified a few genes and observed an unusual phenotypic inheritance pattern. you have noticed that some flies have wings pointing forward and other flies have wings pointing backward. digging in a bit deeper, you discover that the gene wing direction (wdir) controls which direction the wings point, and that if you cross a homozygous backward-wing mother (wdir wdir) with a homozygous forward-wing father (wdir- wdir-), all of the offspring (wdir wdir-) have backward wings. when you perform the reciprocal cross, a homozygous forward-wing mother (wdir- wdir-) with a homozygous backward-wing father (wdir wdir), you observe that all of the offspring (wdir wdir-) have forward-facing wings. how would you account for this bizarre genotype:phenotype relationship?

Answer 1

Explanation:

Only the maternal gene for wing direction is being expressed due to genomic imprinting that silences the paternal gene during gamete formation.