Identification of qRT-PCR reference genes for Chilo suppressalis (Walker) during parasitism by Cotesia chilonis (Matsumura)

Quantitative real-time RT-PCR is highly sensitive approach for identifying and studying genes that function in various biochemical and cellular processes. Choosing the proper reference genes is a necessary step in ensuring the accuracy of results obtained with qRT-PCR. Herein, we evaluate the expression stability of nine potential reference genes in Chilo suppressalis parasitized by Cotesia chilonis. Stability was analyzed using the Delta Ct method, geNorm, NormFinder, and BestKeeper, and our results show that the combination of TUB, EF1 and NADHD was optimal for normalizing expression. The transcription of target genes Hsp60 and CAT in C. suppressalis during parasitism was used to evaluate reference genes, and the results varied depending on the gene selected for normalization. Therefore, it is imperative to choose the proper reference genes to estimate target gene expression accurately in a given experiment. This study provides insights on gene expression in C. suppressalis and is especially relevant to further experiments that explore the effectiveness of C. chilonis in biological control.