Project description:Aliivibrio wodanis and Moritella viscosa have often been isolated together from fish with winter ulcer. Little is known about the interaction between the two bacterial species and how the presence of one bacterial species affects the behaviour of the other. The impact on bacterial growth in co-culture was investigated in vitro, and the presence of A. wodanis has a strong inhibitorial effect on M. viscosa. Further, we have sequenced the complete genomes of these two marine Gram-negative species, and have performed transcriptome analysis of the bacterial gene expression levels from in vivo samples. Using bacterial implants in the fish abdomen, we demonstrate that the presence of A. wodanis is altering the gene expression levels of M. viscosa compared to when the bacteria are implanted separately. The impeding effect on growth and the change in the global gene expression pattern of M. viscosa when the two pathogens co-exists is discussed in this paper.
Project description:Using RNAseq of small RNA libraries isolated from the gill tissue of the Antarctic fish Trematomus bernacchii we have characterized the termal sensitivity of miRNA homologues in these highly stenothermic fish.
Project description:Chemical signals are produced by aquatic organisms following predatory attacks or perturbations such as parasitic infection. Ectoparasites feeding on host fish are likely to cause release of similar alarm cues into the environment due to the stress, wounding and immune response stimulated upon infection. Alarm cues are often released in the form of proteins and peptides and provide important insights into bodily function and infection status. Here we outline a non-invasive method to identify potential chemical cues associated with infection in fish by extracting, purifying and characterizing proteins from water samples from cultured fish. Gel free proteomic methods were deemed the most suitable for protein detection in saline water samples. It was confirmed that proteins could be characterized from teleost water samples and that variation in protein profiles could be detected between infected and uninfected individuals and fish and parasite only water samples. Our novel assay provides a non-invasive method for assessing the health condition of both wild and farmed aquatic organisms. Similar to environmental DNA monitoring methods, these proteomic techniques could provide an important tool in applied biology and aquaculture biology
