Barry, SusanNunez, MeganWoodard, CraigIslam, Rizwana2011-02-162011-02-162011-02-162005-05-09http://hdl.handle.net/10166/642In Drosophila melanogaster, a gene called betaFTZ-F1 mediates the genetic and developmental responses to the steroid hormone 20-hydroxyecdysone (ecdysone). Loss of function mutations of the betaFTZ-F1 gene gives rise to pupal lethality and causes defects in these processes that occur during the prepupal-pupal transition. In the wild type flies, head eversion and wing and leg extension are brought by contractions of the abdominal muscles, which generate hydrostatic pressure to drive these events. In the betaFTZ-F1 mutants, the muscular contractions are not strong enough to generate enough pressure to cause head eversion and wing and leg extension. My hypothesis is that the betaFTZ-F1 gene plays a key role in the innervation of the abdominal muscles by motor neurons. Thus a mutation in the betaFTZ-F1 gene causes a defect in the innervation pattern of these muscles, causing them to be unable to produce strong enough contractions to drive morphogenesis. I tested the hypothesis that the defects observed in betaFTZ-F1 mutants are due to abnormalities in the innervation of abdominal muscles in Drosophila. I compared the innervation pattern of abdominal muscles in fly stocks called Nrv2-GAL4+UAS-GFP, which express green fluorescent protein (GFP) in the nervous system, which also carried mutations in the betaFTZ-F1 gene. I observed a change in the morphology of the innervating motor neurons from 6 hours after puparium formation. The change was more pronounced in flies aged to 12 hours or more after puparium formation. In the betaFTZ-F1 mutants, the two bundles of longitudinal nerves collapse to form one single bundle. The segmental nerves no longer project toward the periphery and innervate muscles at each segment but spread out together near the posterior end of the animals. These results support my hypothesis that betaFTZ-F1 plays a role in the innervation of abdominal muscles in Drosophila.en-USThesispublic