Poster Presentation Society for Molecular Biology and Evolution Conference 2016

Comparative analysis of the thermal stress response in two intertidal Neritid snails (#362)

Peter J Prentis 1 , Shorash Amin 2 , Chris Collett 2 , Daniel Broszczak 2 , Edward K Gilding 3 , Ana Pavasovic 2
  1. School of Earth, Environmental and Biological Sciences, Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD, Australia
  2. School of Biomedical Science, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
  3. Institute for Molecular Biosciences, University of Queensland, Brisbane, Old, Australia

Nerita melanotragus and N. albicilla are widespread intertidal molluscs, distributed across a number of temporally and spatially fluctuating environmental gradients, including abrupt changes in temperature over a tidal cycle. The species differ in their ecology and geographic ranges, as N. melanotragus is a mid-littoral species ranging from temperate to subtropical climes, while N. albicilla is a low-littoral species found in tropical and subtropical regions. Colonisation of different areas in the intertidal zone means that N. melanotragus (mid-littoral) is likely to sustain longer periods of temperature stress than N. albicilla (low-littoral). Consequently, these two species present an interesting case to examine differences in their gene expression patterns in response to the same temperature conditions. In this experiment, nine individual samples from each of N. melanotragus and N. albicilla were randomly allocated into three treatments (14 °C, 22 °C and 31 °C) with three replicates in each treatment. Animals were euthanized, RNA extracted and each individual was sequenced on an Illumina Hiseq. Sequences from each species were assembled and gene expression patterns were determined across the treatment temperatures. The two species had highly divergent patterns of gene expression under treatment conditions. Few differentially expressed genes (~20) were observed in Nerita albicilla, and these were dominated by molecular chaperones. More differentially expressed genes (~100) were observed in N. melanotragus, but no dominant class of genes was observed. This data suggested that N. albicilla had a more significant stress response to temperature and this supports the idea that low-littoral species undergo thermal stress at lower temperatures than mid-littoral species.