AUTHOR=Da Fan , Wan Xiaoju , Lin Guixiang , Jian Jichang , Cai Shuanghu 

TITLE=Cloning, characterization and expression analysis of caspase-8 genes from the golden pompano (Trachinotus ovatus)

JOURNAL=Frontiers in Marine Science

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.1093176

DOI=10.3389/fmars.2022.1093176

ISSN=2296-7745

ABSTRACT=<p>Bacterial infection triggers apoptosis and immunity by regulating the expression of caspases. In this article, we report two <italic>caspase-8</italic> paralogs, termed <italic>ToCas8</italic> and <italic>ToCas8</italic>-like, from an economically important teleost golden pompano (<italic>Trachinotus ovatus</italic>). Caspase-8 is a classic cysteine protease that is essential for the initiation and execution of apoptosis and is a critical regulator in initiating death receptor-induced programmed cell death. The two proteins encoded by <italic>ToCas8</italic> and <italic>ToCas8</italic>-like were characterized by multiple sequence alignment and protein structure analysis showing similarity to their counterparts in vertebrates and exhibiting typical features of the Caspase-8 protein family. Gene synteny analysis further confirmed that two isoforms of <italic>caspase-8</italic> genes exactly existed in golden pompano. Phylogenetic analysis showed that the Caspase-8 proteins of the selected species in the study were clustered together, and Cas8 and Cas8-like were clustered into two different subgroups. In addition, <italic>ToCas8</italic> and <italic>ToCas8</italic>-like were widely distributed and both were expressed at high levels in gill, kidney and intestinal tissues. Transcript levels of <italic>ToCas8</italic> and <italic>ToCas8</italic>-like were significantly upregulated in response to LPS and Poly(I:C) challenges, suggesting that <italic>caspase-8</italic> genes are involved in the immune response to pathogens. In summary, we have identified two isoforms of <italic>caspase-8</italic> in golden pompano that are involved in the immune response. These findings will expand our understanding of the evolutionary history and functional characteristics of caspase-8 genes in vertebrates.</p>