Reference no: EM13119386

The Drosophila wingless gene (wg) was first Wnt family member identified with a role in development. There are several unusual alleles of the wingless gene. wg1 was the first allele identified and homozygous flies are viable but lack wings. Genetic screens for embryonic patterning genes identified wgcx4, which produces a homozygous lethal embryonic segment polarity phenotype. wgr0727 is also homozygous embryonic lethal but the segment polarity phenotype is not as strong as wgcx4. Sp is a dominant mutation that generates extra hairs on the thorax and is homozygous pupal lethal. It is lethal in trans to some alleles of wg, but not all of them, and it has been suggested that this is due to transvection. A P element-induced revertant of Sp, Sprev, is pupal lethal in trans to all lethal wg alleles. Furthermore, over-expression of the wild-type wg+ gene in developing flies mimics the Sp extra bristle phenotype. In trans to a deficiency for the region, all alleles except wg1 are homozygous lethal. wg1, wgr0727, and Sprev show a more severe phenotype in trans to a deficiency than homozygous, whereas the wgcx4 phenotype is not different in hemizygotes or homozygotes. The heterozygous deficiency flies do not show any phenotypes.

Based on this information, list the most likely classification of the different alleles. Choose from the following categories: null, haploinsufficient, hypomorph, antimorph, hypermorph, neomorph. You do not need to use all of the categories. Explain your logic (evidence) for each answer.