Mapping and cloning recessive wing mutations in an undergraduate course. Eric P. Spana, Samuel C. Arnold, S. Canon Brodar, Emily Chang, Karen Y. He, Andrew Hollis, Yanjun Anna Liu, David K. Lung, Sasha McEwan, Uchenna C. Osuji, Ann Prybylowski, Clara Starkweather, Diana L. Xie, Qingyun Li. Department of Biology, Duke University, Durham, NC.

   Drosophila adult visible mutations are valuable for genetic mapping and studying a range of developmental processes. Despite their experimental utility, many wing mutations have not yet been cloned. By employing complementation tests against molecularly defined deficiencies, duplications, and insertion alleles, as well as RNAi knockdowns, we sought to identify genes responsible for four wing mutants: fluted (fl), scooped (scp), folded (fo), and bloated (blo). The fluted (fl) mutation, first identified by Helen Redfield in 1921, displays longitudinal creases adjacent to the 2nd through 5th wing veins. Deficiency crosses narrowed the map region to ~85kb within 90B1-90B2 (~5 genes), and further complementation crosses with insertion lines identified CG5873 as a candidate gene. Described by Muller in 1926, scp mutants display a subtly slight upward curve towards the lateral edges of the wing. We localized scp to two candidate regions spanning a total of ~450 kb through duplication and deficiency crosses (4F10-5C7 & 6B2-6C4). The wings of folded (fo), discovered by Grossman in 1932, remain unexpanded in a varying percentage of adults, with postscutellars bent forward. Using a reported genetic location of fo (1-63), we mapped the mutation to a ~450 kb interval residing in the 15F-16B cytogenetic region. We have also identified a wing pigmentation phenotype on fo flies with expanded wings; whether this wing pigmentation phenotype is associated with fo remains uncertain. The blo mutation, isolated in 1933 by Ives, gives rise to large blisters on the wings. We narrowed blo to a ~165 kb region (44E-44F) using deficiency complementation. We found that a knockdown of sticks and stones in wings phenocopied blo, suggesting that blo may be an adult viable allele of sns. Further molecular analysis will be performed to identify the lesions in the candidate genes.