Analysis of Expression Characteristics of Related Genes in Response to Acute Thermal Stress in the Razor Clam Sinonovacula constricta

Abstract:

The razor clam, Sinonovacula constricta, as a eurythermic bivalve, might have special adaptive mechanisms for defense against environmental stress because of its specialized lifestyle and limited mobility. To understand the expression characteristics of genes involved in different metabolic processes, quantitative reverse transcription PCR technology was used to analyze the expression levels of three types of temperature response candidate genes (molecular chaperone genes, metabolic and immune related genes, and apoptosis genes) based on a transcriptomic analysis in the gills and hepatopancreas of S. constricta under different acute high temperature conditions (30℃, 32℃ and 34℃). The results showed that the expression of molecular chaperone genes was significantly upregulated at 4 h under thermal stress and was positively correlated with temperature. Meanwhile, gills responded earlier than the hepatopancreas. The mRNA expression of metabolic and immune responses and apoptotic genes increased and then decreased in both tissues with the extension of stress time. In conclusion, the regulation of these genes played significant roles to maintain basic homeostasis in S. constricta under heat stress. The expression of immune response genes was more significant in the hepatopancreas. This study provides a theoretical basis for further exploring the molecular mechanisms of high temperature responses of S. constricta and provides candidate genes for molecular marker-assisted breeding in this species under thermal stress.