Genome-wide identification and characterization of the HSP gene superfamily in apple snails (Gastropoda: Ampullariidae) and expression analysis under temperature stress

Abstract

Heat shock proteins (HSPs) play important roles in the response to various stresses as molecular chaperones. Apple snails from the family Ampullariidae have become economically important due to several species mainly from the genus Pomacea were invasive. The recent release of the genomes of ampullariids (P. canaliculata, P. maculata, Lanistes nyassanus, and Marisa cornuarietis) has opened the opportunity for a comprehensive analysis of the HSP superfamily. We identified that the number of HSP from P. canaliculata (PcaHSPs) was greater than that from the other three species. A total of 42 PcaHSPs were distributed on 12 chromosomes and were classified into the families of HSP90, HSP70, HSP60, HSP40, HSP20, and HSP10. Each family formed a monophyletic clade on the phylogenetic trees, except for the HSP40 family. We identified tandem duplication of paralogous genes in PcaHSP70 and PcaHSP20. The RNA-seq data show that the expression profiles of PcaHSPs in different tissues have similar patterns, except that several PcaHSP20 genes revealed tissue-specific expression levels. Moreover, we identified that there were more HSP genes with stronger induction levels in response to hot than cold stress. Our findings will be helpful for future studies on stress response and adaptation focusing on HSPs in apple snails.