Desat2 gene encoding the non-functional M-type which is found in Cosmopolitan populations.
Flies carrying the Z-type desat2Z allele in an M-type background show better tolerance to 4[o]C than do flies carrying the desat2M allele in an M-type background. At -10[o]C, flies carrying the desat2M allele in an M-type background show no consistent survival advantage over flies carrying the Z-type desat2Z allele in an M-type background.
Flies carrying the Z-type desat2Z allele in an M-type background and flies carrying the desat2M allele in an M-type background show some significant differences to starvation stress between genotypes, but these differences are not in a consistent direction.
Flies carrying the Z-type desat2Z allele in an M-type background have a higher 5,9-heptacosadiene to 7,11-heptacosadiene ratio than control desat2M flies (which carry the M-type allele of desat2 in an M-type background). However, the ratio is not as high as seen in natural populations of flies from Zimbabwe populations (which carry the naturally occurring desat27-11HD-low Z-type allele), indicating that there are likely other loci involved in cuticle hydrocarbon composition.
Flies carrying the Z-type desat2Z allele in an M-type background show decreased cold tolerance compared to control desat2M flies.
Flies carrying the Z-type desat2Z allele in an M-type background show increased resistance to starvation compared to control desat2M flies. There is no consistent difference in dessication resistance between the two lines. Mean wing length is not significantly different between the two lines.
Control allele; targeted recombination has been done in an M-type background and this allele has been through the same gene targeting procedure as desat2Z, but in this case (desat2M) the type of desat2 present is unchanged, as the non-functional M-type which is naturally found in Cosmopolitan populations has been replaced with the same M-type form.