The Role of MicroRNA-8 in Cuticle Pigmentation and Brain Function in D. melanogaster

Evan J. Waldron, Vassar College ’12 and Prof. Jennifer A. Kennell

MicroRNAs are a class of RNA that has the ability to reduce gene expression by binding to specific messenger RNAs (mRNAs). A single microRNA can target multiple mRNAs. The phenotype for the deletion of microRNA-8 (miR-8) in Drosophila melanogaster is characterized by decreased pigmentation in the abdominal cuticle and uncoordinated movement. Bioinformatic searches and experiments in cell culture suggest that ebony and bab2, two genes involved in cuticle pigmentation, are direct targets of miR-8. An increased level of Bab2 or Ebony in the cuticle and brain is one possible explanation for the mutant phenotype. We have shown that miR-8 expression partially overlaps with Ebony and completely overlaps with Bab2 in the larval brain. In addition, Ebony, Bab2, and miR-8 are expressed throughout the cuticle. We immunostained for Bab2 and Ebony in order to compare expression levels of either protein in miR-8 mutant and wild type D. melanogaster. So far, we have found no significant difference in the levels of these two potential targets in the larval brain.