Date of Award
Program of Study
Krista C. Dobi
Rebecca F. Spokony
Drosophila melanogaster have two sets of muscle systems: larval muscles and adult muscles. The larval somatic muscle system is established during embryogenesis and is necessary for hatching, feeding, and crawling of the larvae. Like humans, Drosophila muscles have individual characteristics, like unique sizes, shapes, orientations, attachment sites, and innervation patterns by motor neurons. These properties are encoded by a group of transcriptional regulators that are expressed in specific muscle subsets. Currently, there are over twenty known transcription factors required for the development of the 30 distinct larval somatic muscles and specification of those muscle properties. We have examined how muscle-specific neuron defasciculation and innervation occurs using genetics, immunohistochemistry, and fluorescent microscopy to identify muscle-specific factors that regulate the process of neuron innervation. We tested how loss-of-function mutations in lateral transverse muscle-specific transcription factors affect innervation of these muscles by the segmental nerve, to identify muscle-specific factors that regulate the process of neuron innervation. We examined the muscle patterns by immunostaining with antibodies to two sarcomeric proteins: myosin heavy chain (MHC) and tropomyosin (TM). Similarly, we examined the architecture of the segmental nerve in these genetic backgrounds using antibodies that recognized FITC-HRP and Fasciclin II (Fas-II). Confocal microscopy images show wild-type embryos with proper muscle patterning of the four lateral transverse muscles, corresponding to proper nerve branching. However, the apUGO35, mid1, and msh∆68 lines displayed defects in lateral transverse muscle patterning, corresponding to an absence of proper nerve branching.
Tang, Sharon, "Motor Neuron Connections and Innervation of Muscles in Drosophila melanogaster" (2020). CUNY Academic Works.