Identification of a rat brain gene associated with aging by PCR differential display method.

The polymerase chain reaction (PCR) differential display method is a powerful tool to detect and characterize alteration of gene expression in eukaryotic cells. In order to screen the differentially expressed genes between the adult (3 mo) and aged (24 mo) rats, the PCR differential display method was adopted in the present study. One differentially expressed cDNA band (C7-1) was identified and the aged rats expressed more the C7-1 gene than the adult rats in the frontal cortex, but not in the hippocampus and hypothalamus. The C7-1 cDNA band was recovered, reamplified, and subcloned as a probe in Northern blot analysis. A transcript of approx 2.8 kb was expressed in the frontal cortex of both the adult and aged rats, but the C7-1 mRNA level was increased for 52% in the aged rats. The C7-1 gene was then sequenced that contains 243 bp. We have found that the C7-1 cDNA shows no significant homology to any published genes, suggesting that the C7-1 gene is an unknown gene associated with aging. This study provides the first evidence to show that there is alteration in gene expression associated with aging by using the PCR differential display method.