Selection of reference genes for microRNA quantitative expression analysis in Chinese perch, Siniperca chuatsi

Real-time quantitative reverse transcription PCR (RT-qPCR) is one of the most effective and sensitive techniques in gene expression assay, for which selection of reference genes is a prerequisite. In teleost species, such as Chinese perch, the expression profiling of miRNAs as reference genes for RT-qPCR has not been intensively studied. In the present study, the expression profiles of six miRNAs (miR-101a, miR-146a, miR-22a, miR-23a, miR-26a and let-7a) and one small nuclear RNA (U6) were assayed with RT-qPCR in different adult tissues, developmental stages and growth conditions of Chinese perch, Siniperca chuatsi. The analyses revealed that embryonic developmental stage is an important variability factor in the expression stability of miRNAs. All six miRNAs exhibited better expression consistency than U6 in most of the conditions examined, and therefore, they may be more suitable as a reference gene for miRNA quantification. When different tissues and developmental stages were considered, miR-22a demonstrated the most consistent expression pattern, and the best combination of reference genes was miR-22a and miR-23a. Our study offers useful data for selecting miRNAs as reference genes for RT-qPCR analysis of miRNAs in teleost fishes under different conditions.