Identification of rat lung - prominent genes by a parallel DNA microarray hybridization

Background: The comparison of organ transcriptomes is an important strategy for understanding gene functions. In the present study, we attempted to identify lung-prominent genes by comparing the normal transcriptomes of rat lung, heart, kidney, liver, spleen, and brain. To increase the efficiency and reproducibility, we first developed a novel parallel hybridization system, in which 6 samples could be hybridized onto a single slide at the same time. Results: We identified the genes prominently expressed in the lung ( 147) or co-expressed in lung-heart ( 23), lung-liver ( 37), lung-spleen ( 203), and lung-kidney ( 98). The known functions of the lung-prominent genes mainly fell into 5 categories: ligand binding, signal transducer, cell communication, development, and metabolism. Real-time PCR confirmed 13 lung-prominent genes, including 5 genes that have not been investigated in the lung, vitamin D-dependent calcium binding protein ( Calb3), mitogen activated protein kinase 13 ( Mapk13), solute carrier family 29 transporters, member 1 ( Slc29a1), corticotropin releasing hormone receptor ( Crhr1), and lipocalin 2 ( Lcn2). Conclusion: The lung-prominent genes identified in this study may provide an important clue for further investigation of pulmonary functions.