Meeting Abstract
Antarctic Notothenioids are known to display a narrow thermal tolerance window and their reduced capacity to acclimate to a warming ocean is exacerbated by the loss of the heat shock response (HSR) that can help to mitigate the cellular level effects of elevated ocean temperatures. The lack of the inducible HSR has been extensively investigated at the transcriptional level in several species, yet we have little insight into the mechanism underlying this disruption in mRNA regulation. In particular, the role of post-transcriptional regulation of mRNA stability by microRNAs in the HSR has received little to no attention, especially in polar fish. MicroRNAs (miRNAs) are small (~22 nucleotides), evolutionarily conserved, non-coding RNAs that predominantly downregulate gene expression in a sequence specific manner. The aim of this study is to annotate miRNAs from the transcriptome of Trematomous bernacchii and characterize their regulatory role during a thermal stress event. To this end, our deep sequencing analysis identified a total of 125 different miRNAs in T. bernacchii gill tissue, of which 19 displayed differential expression during an acute thermal stress. We further assessed the biological function of these thermoregulated miRNAs using computational prediction programs to identify putative gene targets followed by analysis of the corresponding changes in transcript abundance. This integrated DE analyses of miRNAs and mRNAs in the T. bernacchii transcriptome provides some of the first insights into the role miRNAs play during a cellular stress response of an extreme stenotherm.
