Evaluation of a genomics platform for cross-species transcriptome analysis of recombinant CHO cells

Microarray technology for mammalian cells has been utilized mainly for humans, mouse, and rat gene expression analysis. In this approach the feasibility of cross-species hybridization experiments using Chinese hamster ovary (CHO) cells was evaluated. Sequence alignments of available data for CHO were performed against mouse and rat transcripts to determine the homology between the investigated species. We implemented a probability model based on this homology in order to estimate the chance for successful hybridization using Agilent's 60-mer oligonucleotide platform. Heat-shock expression data from CHO, mouse 3T3, and rat A10 cells were generated to determine intraspecies variability, reproducibility, and specificity in order to assess the accuracy of this method. Detected signature genes, in particular from studies with the mouse arrays, showed a reliable similarity between these two rodents and were confirmed by quantitative RT-PCR. Our findings provide evidence that cross-species analysis can be a useful tool to study gene expression profiles of related organisms for which species-specific microarrays are not available.