Project description:We mapped and sequenced the SLC26A5 of the American bullfrog from its inner ear cDNA using RNA-Seq. The frog SLC26A5 cDNA was 2,292 bp long, encoding a polypeptide of 763 amino acid residues, with 40% identity to mammals. After isolating the prestin gene of the frog, we generated a stable cell line transfected with this new coding gene and found it possessing similar electrophysiological features as the hair cells from the frog’s auditory organ. Our experiment demonstrated that the new coding gene could encode a functionally active protein conferring NLC to both frog HCs and the mammalian cell line.
Project description:Functional modifications shape the ability of populations to cope with anthropogenic environmental changes. These modifications are mediated by complex interactions between transmitted and non-transmitted changes which limit their prediction. To study how these changes are intertwined with evolutionary processes in a case of persistent anthropogenic environmental change, we characterized population structure, genetic diversity and individual response on gene expression of the tree frog Hyla orientalis along a gradient of radioactive contamination around the Chernobyl nuclear power plant. We detected lower effective population size in populations most exposed to ionizing radiation that is not compensated by migrations from surrounding areas. We also highlight a decreased body condition of frogs living in the most contaminated area, a peculiar transcriptomics signature and stop-gained mutations in genes involved in energy metabolism. Population most exposed to ionizing radiation in the Chernobyl exclusion zone experience both genetic drift and functional changes that collectively point towards deleterious effects of ionizing radiation on tree frogs and potential difficulty to adapt to this novel environment.
Project description:Determining the mechanisms of host-pathogen interaction is critical for understanding and mitigating infectious disease. Mechanisms of fungal pathogenicity are of particular interest given the recent outbreaks of fungal diseases in wildlife populations. Our study focuses on Batrachochytrium dendrobatidis (Bd), the chytrid pathogen responsible for amphibian declines around the world. Previous studies have hypothesized a role for several specific families of secreted proteases as pathogenicity factors in Bd, but the expression of these genes has only been evaluated in laboratory growth conditions. Here we conduct a genome-wide study of Bd gene expression under two different nutrient conditions. We compare Bd gene expression profiles in laboratory growth media and in host tissue (i.e., frog skin). A large proportion of genes in the Bd genome show increased expression when grown in host tissue, indicating the importance of studying pathogens in their infection environment. A number of gene classes show particularly high levels of expression in host tissue, including three families of secreted proteases (metallo-, serine- and aspartyl-proteases), adhesion genes, lipase-3 encoding genes, and a group of phylogenetically unusual crinkler-like effectors. We discuss the roles of these different genes as putative pathogenicity factors and discuss what they can teach us about Bd's metabolic targets, host invasion, and pathogenesis. One 12-plex chip was analyzed from 12 RNA samples extracted from Batrachochytrium dendrobatidis grown in 2 substrates. Six biological replicates were used for each substrate - sterile frog skin and tryptone nutrient broth. The same dye, Cy5, was used for all samples.