Identification of Novel Genes Involved in Zinc Metabolism in Caernorhabditis Elegans

Zinc is an essential element for proper cell function in all organisms. High levels of zinc cause metal toxicity; interestingly, low levels of zinc are detrimental for many organisms. Although zinc homeostasis is necessary, the mechanisms that regulate this process have yet to be fully understood. We are investigating how zinc is metabolized and what genes are involved in this process. Previous studies have established the functionality and importance of four zinc inducible genes in C. elegans, mtl-1, mtl-2, cdf-2 and ttm-1. These genes have a conserved promoter region that we used to make a weight matrix. Using BLAST MAST with the upstream sequence and FIMO with whole genome sequence and manual locus check, we identified 17 genes that contain the conserved promoter element. We hypothesized that these genes may be induced by dietary zinc and have a role in zinc metabolism. To test our hypothesis we exposed a synchronized population of larval stage 4 C. elegans to varying concentrations of zinc, and by qRT-PCR analyzed mRNA levels normalized to the reference genes, rps-23 and ama-1. Our results suggest that a novel gene, T26H2.5, is induced by zinc, showing a consistent 14-fold increase in mRNA levels after zinc exposure. To determine the function of T26H2.5, we are currently performing RNAi experiments, which include zinc sensitivity tests. The analyses of the remaining genes will be conducted to determine their role in zinc metabolism. These experiments will serve as a starting point for new studies on the genes involved in zinc metabolism.