Publication Synopsis

Gene Expression Profiling of the Left Ventricles in a Rat Model of Intrinsic Aerobic Running Capacity. Physiol Genomics

In a study of cardiorespiratory function and aerobic running capacity (ARC), scientists used global genomic approaches to identify differentially expressed cardiac genes that may serve as cardiovascular risk factors. They employed a rat model comprising two strains: DA (a high ARC strain) and COP (a low ARC strain). Genetic linkage demonstrated that genes associated with aerobic capacity were heritable and the chromosomal locations were identified.

Inbred strains of DA and COP as well as bred F1(DAXCOP) were used in the experiment. RNA isolated from left ventricles after tests was applied to the Affymetrix 7 Rat Genome U34 array set. Quantitative PCR and identification of chromosomal locations were performed to validate and confirm the signature genes. The IPA application was applied to generate gene networks and identify the functional relationships of the candidate genes.

By comparing the high ARC strain (DA) to the low ARC strain (COP), 199 differentially expressed probe sets were identified. Nine probe sets were matched to known chromosomal locations based on their sequences and validated by quantitative real time PCR. Using the IPA application, 50 differentially expressed genes were identified from 13 biological networks containing a total of 135 genes, as shown in supplemental Table 3 of the paper. Three large networks with 40 differentially expressed genes indicating potential functions are listed in Table 4 of the paper. Chromosomal locations of 85 genes from these networks were examined, but these genes were not among the 199 genes identified by the microarray analysis. Four genes recognized by the IPA application were mapped to known ARC regions. These genes may be considered potential risk factors for cardiorespiratory disease.