Meeting Abstract

P1.17  Wednesday, Jan. 4  Comparative Transcriptomics of Two Freshwater Mussels, Villosa nebulosa and Villosa lienosa, in Response to Heat Shock PERKINS, Samantha L.*; JENNY, Matthew J.; University of Alabama; University of Alabama

The impact of stress related to global warming of surface waters has been studied extensively on multiple levels of biological organization. However, the impact of warming on freshwater mussels (Bivalvia: Unionidae), keystone species in many of the worlds freshwater systems, is poorly understood. A next generation sequencing approach was undertaken to identify genes that were differentially expressed in response to temperature stress. Two species of mussel native to Alabama (USA), Villosa nebulosa and Villosa lienosa, were chosen for study because of the differences in habitat range and conservation status. V. nebulosa is restricted to a relatively narrow range and is of moderate conservation risk, while Villosa lienosa has a large geographic range and is currently stable. Both species were subjected to heat shock (3°C above ambient 22°C) and tissue samples were collected at 3 and 6 hours post shock to produce the RNA template for sequencing. ~330,000 sequence reads (mean length of 100 base pairs) were generated for each species. Sequence assembly yielded 17,637 and 21,657 contigs for V. nebulosa and V. lienosa, respectively. Contigs were blasted against the NCBI nonredundant database and further annotated by assignment of gene ontology categories. BLAST results confirmed a significant number of genes related to heat shock, oxidative stress and general cellular stress. Seventeen genes were chosen as potential molecular biomarkers across multiple functional categories (heat shock, oxidative stress, growth, metabolism and reproduction) for comparative expression profiling via quantitative real time-PCR. Future work will involve quantitatively modeling the effects of global warming on freshwater mussels by integrating molecular, metabolic, and physiological parameters the determine the effects of heat stress on life history characteristics.