Temperature and Development Impacts on Housekeeping Gene Expression in Cowpea Aphid, Aphis craccivora (Hemiptera: Aphidiae)

Quantitative real-time PCR (qRT-PCR) is a powerful technique to quantify gene expression. To standardize gene expression studies and obtain more accurate qRT-PCR analysis, normalization relative to consistently expressed housekeeping genes (HKGs) is required. In this study, ten candidate HKGs including elongation factor 1 α ( EF1A ), ribosomal protein L11 ( RPL11 ), ribosomal protein L14 ( RPL14 ), ribosomal protein S8 ( RPS8 ), ribosomal protein S23 ( RPS23 ), NADH-ubiquinone oxidoreductase ( NADH ), vacuolar-type H+-ATPase ( ATPase ), heat shock protein 70 ( HSP70 ), 18S ribosomal RNA ( 18S ), and 12S ribosomal RNA ( 12S ) from the cowpea aphid, Aphis craccivora Koch were selected. Four algorithms, geNorm , Normfinder , BestKeeper , and the ΔC t method were employed to evaluate the expression profiles of these HKGs as endogenous controls across different developmental stages and temperature regimes. Based on RefFinder , which integrates all four analytical algorithms to compare and rank the candidate HKGs, RPS8 , RPL14 , and RPL11 were the three most stable HKGs across different developmental stages and temperature conditions. This study is the first step to establish a standardized qRT-PCR analysis in A . craccivora following the MIQE guideline. Results from this study lay a foundation for the genomics and functional genomics research in this sap-sucking insect pest with substantial economic impact.