Creating a heterozygous male

Hermaphrodite Parent genotype

Male Parent genotype X

Male gametesFemale gametes

Progeny genotype

Which progeny are you continuing with? Why?

Progeny phenotypesand ratios

Hermaphrodite Parent genotype

Male Parent genotype X

Male gametesFemale gametes

F1 Progeny genotype and ratios

F1 Progeny phenotypes

Linkage 1: Cross with Unlinked unc

+/+ ; unc/unc

Linkage 2: Selfing of hermaphrodite from unlinked cross

hermaphrodite

X self cross

gametes

Progeny genotype

Progeny phenotypes and ratios

Hermaphrodite Parent genotype

Male Parent genotype X

Male gametesFemale gametes

Progeny genotype

Progeny phenotypesand ratios

Linkage 1: Crossing with Linked unc

Which progeny are you continuing with? Why?

+ unc/ + unc

Linkage 2: Selfing of hermaphrodite from linked cross

hermaphrodite

X self cross

gametes

Progeny genotype

Progeny phenotypes and ratios

Mapping 1: Making the double mutant

hermaphrodite

X self cross

gametes

Progeny genotype

Progeny phenotypes and ratios

What if the genotype of the parent was + unc/+ unc?

Mapping 2: Making heterozygotes for mapping

Hermaphrodite Parent genotype

Male Parent genotype X

Male gametesFemale gametes

Progeny genotype

Progeny phenotypesand ratios

Why might you see Dpy Unc progeny?

Mapping 3: Test Cross

Hermaphrodite Parent genotype

Male Parent genotype X

Male gametesFemale gametes

Progeny genotype

Progeny phenotypesand ratios

ParentalRecombinant

Symbols to Know for Crosses

• a//a – a is the allele and // represents the chromatids – there are two for a diploid organism – sometimes written as /

• a b//a b – two different genes on the same chromosome

• a//a ; b//b – two different genes on different chromosomes

• X – symbolizes mating between two different individuals

• X - symbolizes a self cross – when the hermaphrodite worms fertilize their own eggs