Question 3.2: (16 points total) For your Bios 399 project, you are studying 3 recessive mutations that affect body color, wing size, and eye color in Drosophila. The $p$ gene affects body color, and $p$ mutant flies have a pale body. The $srt$ gene affects wing size, and $srt$ mutants have short wings. The $w$ gene affects eye color, and $w$ mutants have white eyes. These genes are linked on chromosome 1, but their order and map position are unknown. Your advisor asks you to map these genes, so you test-cross females heterozygous for the mutant alleles with homozygous mutant males as indicated below.
$p/p \cdot srt/srt \cdot w/w \text{ ?} \times p/p \cdot srt/srt \cdot w/w \text{ ?}$ (test-cross)
In the progeny of this cross, you observe the gametic genotypes in the table below. Use a check mark to indicate the parental gametes and recombinant gametes between the indicated gene pairs. (7 points)
gamete
genotypes
#
parentals
p to srt recomb
p to w recomb.
srt to w recomb.
p- srt- w+
379
p- srt+ w+
67
p+ srt- w+
48
p- srt- w-
6
p+ srt+ w+
5
p+ srt+ w-
382
p- srt+ w-
44
p+ srt- w-
69
total
1000
Use this information to draw a genetic map indicating the distance between each pair of genes in cM. Show your work for full or partial credit. (9 points)
