Selection and Validation of Reference Genes for Quantitative Real-Time PCR Expression Analysis of Candidate Genes in Carposina sasakii (Lepidoptera: Carposinidae)

Carposina sasakii is one of the most important pests on the quality of stone and pome fruits. Investigation of a gene expression level in the species is hampered because of the gap of validated reference genes. The expression variation in the transcription levels of eight candidate reference genes, Actin (ACT), Tubulinbeta-1 (TUB), Ribosomal protein 49 (RP49), Elongation factor1-alpha (EF-1a), Elongation factor1-b (EF-1b), Elongation factor1-d (EF-1d), Ribosomal proteinL13 (RPL13) and Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), were analyzed by quantitative real-time PCR (qPCR). The stability and ranking of these gene expression profiles in three organ types (head, thorax and abdomen), three developmental stages (larva, pupa and moth), and five diapause states (non-diapause, pre-diapause, diapause 0 d, diapause 20 d and diapause 60 d) were assessed using two algorithm-based methods, geNorm and NormFinder. EF-1a, ACT and GAPDH were evaluated to be the three stable reference genes based on the important observations and comprehensive analysis, whereas TUB and EF-1b showed low expression stability. Best gene combinations for different qPCR analysis in C. sasakii could be chosen from the three stable reference genes, the using of two reference genes is sufficient to effectively normalize qPCR data in C. sasakii. The study laid the foundation for gene expression analysis in C. sasakii and provided new information for the selection of reference genes.