Identification of age-dependently expressed genes in mouse liver by differential display-PCR analysis

The aim of this study was to identify genes expressed in an age-dependent manner in mouse (Mus musculus) liver. To search for age-dependently expressed genes, we used a fluorescence differential display-PCR (FDD-PCR) technique on total RNA extracted from mouse livers collected at seven different developmental stages. All differentially expressed cDNAs detected by FDD-PCR were reamplified, subcloned and sequenced, and six genes were confirmed to show age-dependent expression by quantitative real-time PCR analysis. Nucleotide sequence analyses showed that four of them had high homology with known genes (mitochondrial DNA, cytosolic aldehyde dehydrogenase, cell division cycle 2-like 5 and complement component 8 alpha polypeptide), and two with expressed sequence tags of unknown genes. The FDD-PCR technique was effective for detecting novel age-dependently expressed genes, and also for newly characterizing individual expression patterns of known genes. The age-dependent expression patterns of known genes revealed in this study may provide an opportunity to investigate the unknown physiological roles of the proteins they encode.