Question

In the F3 genetic screen scheme using mutated zebrafish:

a) Why are the offsprings from the first step mated with a WT organism?

b) Why are the 2 F2 fishes mated in the scheme?

c) What is the probability of obtaining a homozygous mutant in the F3 generation?
d) In which generations do you separate/ don't separate the siblings? Why?

e) What genotype does the organism need to have in order to visibly observe a change? Why?

Answer 1

in the F3 genetic screen scheme using mutated zebrafish

a.) In the first step the organisms are mated with WT organism to create the F1 generation.

b.) The 2 F2 fishes are mated because 2 different family of fish will have different mutation but the fish in same family will have same one. Mating the 2 F2 results in F3 generation

c.) The probablity of getting a homozygous mutant in F3 generation is 50%.