title: Validation of rat reference genes for improved quantitative gene expression analysis using low density arrays.
abstract: Real-time PCR has become increasingly important in gene expression profiling research, and it is widely agreed that normalized data are required for accurate estimates of messenger RNA (mRNA) expression. With increased gene expression profiling in preclinical research and toxicogenomics, a need for reference genes in the rat has emerged, and the studies in this area have not yet been thoroughly evaluated. The purpose of our study was to evaluate a panel of rat reference genes for variation of gene expression in different tissue types. We selected 48 known target genes based on their putative invariability. The gene expression of all targets was examined in 11 types of rat tissues using TaqMan low density array (LDA) technology. The variability of each gene was assessed using a two-step statistical model. The analysis of mean expression using multiple reference genes was shown to provide accurate and reliable normalized expression data. The least five variable genes from each specific tissue were recommended for future tissue-specific studies. Finally, a subset of investigated rat reference genes showing the least variation is recommended for further evaluation using the LDA platform. Our work should considerably enhance a researcher's ability to simply and efficiently identify appropriate reference genes for given experiments.
authors.affiliation: Pfizer Global Research and Development, Pfizer Inc., Groton, CT 06340, USA. jenny.h.cai@pfizer.com
authors.forename: Jenny Hong
authors.initials: JH
authors.lastname: Cai
authors.forename: Shibing
authors.initials: S
authors.lastname: Deng
authors.forename: Steven W
authors.initials: SW
authors.lastname: Kumpf
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Lee
authors.forename: Panayiotis
authors.initials: P
authors.lastname: Zagouras
authors.forename: Anne
authors.initials: A
authors.lastname: Ryan
authors.forename: Dan S
authors.initials: DS
authors.lastname: Gallagher
mesh_terms: D000818:Animals; D020869:Gene Expression Profiling; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats / Q000235:genetics* / Q000378:metabolism; D012016:Reference Values
chemical_list: D012333:RNA, Messenger