Evaluation of qPCR Reference Genes For Taimen (Hucho Taimen)

As a powerful and attractive method for detecting gene expression, qRT-PCR has been broadly used in aquacultural research. Understanding the biology of taimen (Hucho taimen) has attracted increased interest because of its ecological and economic values. Stable reference genes are required for the reliable quantification of gene expression, but such genes have not yet been optimised for taimen. In this study, the stability levels of 10 commonly used candidate reference genes were evaluated using four methods, geNorm, NormFinder, BestKeeper and RefFinder. The expression levels of the 10 genes were detected using samples from 48 experimental groups that consisted of six tissues (blood, heart, brain, gill, skin and liver) collected under five heat-stress conditions (18, 20, 22, 24 and 26°C) and four heat-stress processing times (4, 24, 48 and 96 h). RPS29 and RPL19 were the most stable genes among all the samples, whereas 28S rRNA, ARBPR and 18S rRNA were the least stable. These results were verified by an expression analysis of the heat-stress genes (hsp60 and hsp70) of taimen. In conclusion, RPS29 and RPL19 are the optimal reference genes for qRT-PCR analyses of taimen, irrespective of the tissue and experimental conditions, and these results allow the reliable study of gene expression in taimen.