Now you will perform a testcross for the same flies used abo

Now you will perform a testcross for the same flies used above in Part 1 of this assignment. You have established a true-breeding mutant line with curved wings (c), which is controlled by a single gene on chromosome 2, and sepia eyes (se), which is controlled by a single gene on chromosome 3. You establish a parental cross between true-breeding males with curved wings and sepia eyes and true-breeding wild-type females. You then mate the F1 females to males that are true-breeding for curved wings and sepia eyes to generate the F2 generation. Map out this cross below, including expected genotypes and phenotypes of males and females at all stages of the experiment. Include the expected phenotypic ratio for the F2 generation.

Solution

Female: c+, se+/c+, se+

Male: c, se/Y

The cross between curved wings and sepia eyes males vs wild-type females

c se/ Y x c+ se+/ c+ se+

F1 Females: c+ se+/c se (Wild type)

Males : c+ se+/ Y (Wild type)

F2 cross between the male and female from F1

c+ se+/c se x c+ se+/ Y

F2 Females: c+ se+/c+ se+ (Wildtype) and c+ se+/c se (Wild type)

Males: c+ se+/Y (wild type) and c se/Y (Mutant)

Phenotypic ratio of F2 generation is 3:1 (Wildtype : Mutant)