A geneticist discovers a new mutation in Drosophila melanogaster that causes the flies to shake and quiver. She calls this mutation spastic (sps) and determines that it is due to an autosomal recessive gene. She wants to determine whether the gene encoding spastic is linked to the recessive gene for vestigial wings (vg).

She crosses a fly homozygous for spastic and vestigial traits with a fly homozygous for the wild-type traits and then uses the resulting F1 females in a testcross.

Write out the experimental design for this test cross and indicate the progeny genotypes and expected proportions of these genotypes if the loci are completely linked.