Preliminary Study On The Thermal Stress Response Mechanism Of Unfolded Protein Response(UPR) In Oyster Crassostrea Gigas Based On Transcriptome Data

UPR is a group of signaling pathways and it is essential for cell survival under endoplasmic reticulum(ER)stress.When the unfolded proteins are accumulated in ER lumen,UPR can strength the ability of protein folding and degradation to maintain the cell homeostasis through decreasing overall protein synthesis.Due to the vital roles in cell stress response and protein folding,UPR has been paid more and more attentions.Its constitution and multiple regulations have been elucidated well in mammalians,fruit flies,worms and yeasts.Molluscs(including bivalves)distribute extensively under various environments,which demonstrate species diversities and show extraordinary adaptation and survival abilities.Because of the homeostasis under different ER stressors,it is important to study molluscan UPR for understanding its distribution characters,living habits and environmental adaption.In the present study,based on deep-digging and comparing of high throughput RNA sequence files of C.gigas hemocytes after 6,12 and 24 h heat treatments,the research was focused on UPR mechanism details to 1)reveal the constitution and expression patterns after different heat treatment time.From the view of different treatment time,UPR signaling pathways responses positively in general.By analyzing the co-expressed genes of different treatment time,PERK was found to be the first responder,the expression of IRE1 and ATF6 signaling pathways were more complicated than PERK and the organism tended to recover cell vitality by IRE1 signaling pathway.2)This study also investigated the crosstalk between important immunity pathways and UPR.By building the networks on the basis of Kappa matrix,the MAPK was found to be the most intimate pathway which related with UPR in thermal stressed oysters.This study is contributed to better understand the molluscan UPR under thermal stress,as well as provide reference for specific pathway’s research and its crosstalk with entire cell immunity responses.