Expression characteristics analysis of major QTL candidate genes inresponse to high temperature stress in turbot (Scophthalmus maximus)

Turbot (Scophthalmus maximus) is an important economic species extensively cultured in China. In this study, we exerted acute high temperature stress on turbot to identify the expression characteristics of four candidate genes including UBE2H, p53, ZNF469, and MAGI2 genes in the liver, gill, spleen and skin. These genes are derived from the QTL related to high temperature resistance located at high-density genetic linkage maps. The relative expressions of UBE2H, p53, ZNF469, and MAGI2 mRNA in four experimental groups (temperature 20 °C, 23 °C, 25 °C and 28 °C)and one control group (temperature 14 °C) were tested using real-time quantitative PCR. Data analysis demonstrated that the four genes were expressed in all tissues, and the expression levels were tissue and temperature specific. The relative expression of UBE2H mRNA firstly increased and then decreased in four tissues. The expression levels in the liver, spleen, and skin tissues increased rapidly at 20 °C and reached a peak value, and peaked at 23 °C in gill tissue. The expression of P53 mRNA increased first and then decreased in four tissues. However, the expression of p53 increased sharply at 28 °C and peaked significantly. It was speculated that the tissue was severely damaged and the cells are heavily apoptotic. ZNF469 and MAGI2 were abundantly expressed at 20 °C in four tissues, than other temperatures. Therefore, we think that both can serve as biomarkers for response to high temperature stress in turbot.