Date of Award

Spring 5-11-2012

Degree Type

Honors College Thesis


Biological Sciences

First Advisor

Sandra Leal

Advisor Department

Biological Sciences


The Drosophila midline (mid) transcription factor gene encodes a highly conserved invertebrate ortholog of the mammalian Tbx20 gene essential for regulating the development of diverse tissues including the central nervous system (CNS), epidermis and heart. Decreasing mid transcript levels within larval eye discs using RNAi (mid- RNAi) results in poorly organized IPCs and in adult eyes, interommatidal bristles derived from sensory organ precursors are significantly reduced in number within the ventral eye field. We also observe gross abnormalities in bristle polarity, ommatidial organization, cellular adhesion and pigmentation in adult mid-RNAi flies. By combining a classical genetic modifier screen with the established RNAi methods, we set out to identification mid-interacting genes and from this screen found that mid potentially interacts with members of the pexin gene family. Pexin proteins are critical for regulating peroxisome structure and function. Placing heterozygous mutant alleles of several pexin genes within the mid-RNAi background did not enhance or suppress the mutant bristle phenotype. However, we found that overexpressing pexin10 in the mid-RNAi genetic background nearly complete suppressed or rescued the mutant bristle phenotype. These results suggest that peroxisomal functions are compromised in cells of mid-RNAi larval eye discs since expression of a critical pexin gene, pexin10, recovered the cells to their wild- type morphologies. Future research will elucidate how mid functions to regulate peroxisome function.

Included in

Biology Commons