Analytical approach for selecting normalizing genes from a cDNA microarray platform to be used in q-RT-PCR assays: A cnidarian case study

Research in gene function using Quantitative Reverse Transcription PCR (q-RT-PCR) and microarray approaches are emerging and just about to explode in the field of coral and cnidarian biology. These approaches are showing the great potential to significantly advance our understanding of how corals respond to abiotic and biotic stresses, and how host cnidarians/dinoflagellates symbioses are maintained and regulated. With these genomic advances, however, new analytical challenges are also emerging, such as the normalization of gene expression data derived from q-RT-PCR. In this study, an effective analytical method is introduced to identify candidate housekeeping genes (HKG) from a sea anemone (Anthopleura elegantissima) cDNA microarray platform that can be used as internal control genes to normalize q-RT-PCR gene expression data. It is shown that the identified HKGs were stable among the experimental conditions tested in this study. The three most stables genes identified, in term of gene expression, were beta-actin, ribosomal protein L12, and a Poly(a) binding protein. The applications of these HKGs in other cnidarian systems are further discussed.