Computational analysis of variation in C. elegans ugts

Caenorhabditis elegans are free-living nematodes with a relatively short life cycle and a wealth of genomic information across multiple databases. Uridine diphosphate-glycosyltransferases (UGTs) are a family of enzymes involved in Phase II modification of xenobiotics in C. elegans , which is the addition of a sizeable water-soluble molecule to a xenobiotic to allow for its excretion out of a cell. Little is known about the variation in UGTs across wild isolates and how that might affect their innate immune response. We analyzed the diversity in ugt genes across C. elegans isolates from different geographical locations from the Caenorhabditis elegans Natural Diversity Resource (CaeNDR) database. This was accomplished using whole genome data and data identifying genome regions as hyper-divergent for each isotype. We implemented three steps to identify ugt genes and make inferences based on their variation. First, we created a catalog of UGTs in the N2 reference strain and used them to create a phylogenetic tree that depicts the relationships between the UGT protein sequences. We then quantified ugt variation using the strains from the CaeNDR database and used their data to remove hyper-divergent ugt genes. The third step was to catalog the occurrence of minor allele frequency (MAF) > 0.05 for all the ugts to compare how that aligned with genes classified as hyper-divergent by CaeNDR. Of the 67 ugt genes analyzed, 18 were hyper-divergent. This research will help improve our understanding of ugt variation in C. elegans .