Tanner crab ( Chionoecetes bairdi ) are an economically important species that is threatened by ocean warming and Bitter Crab Disease, which is caused by an endoparasitic dinoflagellate, Hematodinium . Little is known about disease transmission or its link to host mortality, or how ocean warming will affect pathogenicity or host susceptibility. To better
understand how temperature and infection influence host physiology, we performed a temporal transcriptomic analysis on crab infected with Hematodinium and uninfected crab exposed to either ambient (7.5˚C), elevated (10˚C), or decreased (4˚C) temperature treatments. After assembling a transcriptome and performing a multifactor differential gene expression analysis, we found genes influenced by temperature in relation to infection, and detected some of those genes over time at the individual level using RNAseq data from one crab. Biological processes associated with those genes include lipid storage, transcription, response to oxidative stress, cell adhesion, and morphogenesis. Alteration in lipid storage and transcription provide insight into how temperature impacts energy allocation in Hematodinium infected crabs. Alteration in expression patterns in genes associated with morphogenesis could suggest hemocytes were changing morphology and/or type in response to temperature. This project provides insight into how Hematodinium infection could influence crab physiology as oceans warm.