Regulatory Factor X (RFX) transcription factors (TF) are present in most eukaryotes and are important for regulating processes such as the cell cycle, brain development, neural function, and ciliogenesis. The only C. elegans RFX TF, DAF-19, has four known isoforms: A, B, C, and M. Recent studies suggest DAF-19 A/B, the longest isoforms varying only by one exon, are important for synaptic protein maintenance. However, the molecular details of this regulation are not yet understood. DAF-19A and B may be activating genes coding for proteins that inhibit synaptic protein degradation or may inhibit genes encoding proteins that activate synaptic protein degradation. Failing to maintain healthy synapses has been correlated with neurodegenerative disease initiation or progression, including early stages of Alzheimer’s. The purpose of this study was to identify gene targets of DAF-19A/B in C. elegans. Transgenes for three putative genes, hex-1, T07F10.1, and Y73F8A.11, were constructed so that the promoter regions of each gene regulate the expression of GFP. Expression of each transgene was characterized in two strains of animals: one with a functional daf-19 gene and one with a daf-19 mutation. The expression of GFP was compared between these two strains, via confocal microscopy, to determine whether DAF-19 regulates the expression of that gene. All genes showed DAF-19-dependent changes in their expression patterns, especially in the nervous system. Furthermore, a behavioral investigation, via a roaming and dwelling assay, revealed that mutant alleles of these three genes phenocopy the effect of a daf-19 mutatation. Finally, a transformation rescue experiment was designed to further test the effect of mutant alleles of these three genes.
Level of Honors
summa cum laude
Elizabeth De Stasio
Esemen, Yagmur, "Identifying the Neural Targets of DAF-19 in Caenorhabditis Elegans" (2013). Lawrence University Honors Projects. Paper 48.