Project description:YerA41 is a myoviridae bacteriophage that was originally isolated due its ability to infect Yersinia ruckeri bacteria, the causative agent of enteric redmouth disease of salmonid fish. Several attempts to determine its genomic DNA sequence using traditional and next generation sequencing technologies failed, indicating that the phage genome is modified such way that it is an unsuitable template for PCR amplification and sequencing. To determine the YerA41 genome sequence we isolated RNA from phage-infected Y. ruckeri cells at different time points post-infection, and sequenced it. The host-genome specific reads were substracted and de novo assembly was performed on the unaligned reads.
Project description:Juvenile rainbow trout were exposed to two different concentrations of 17β-estradiol (E2) (2 or 20 mg/kg feed), and then infected with three concentrations of Yersinia ruckeri, a bacterial pathogen causing massive losses in wild and farmed salmonid populations. Infection with Y. ruckeri caused mortality of trout, and this effect was significantly enhanced by simultaneous exposure to high E2 dose. Analysis of hepatic gene expression profiles revealed complex regulations of pathways involved in immune responses, stress responses and detoxicification pathways. E2 markedly reduced expression of several genes implicated in xenobiotic metabolism. The results suggest that the interaction between pathogen and E2 interfered with the fish’s capability of clearing toxic compounds. The findings of the current study add to our understanding of multiple exposure responses in fish.
