Differential expression of diacylglycerol kinase iota and L18A mRNAs in the brains of alcohol-preferring AA and alcohol-avoiding ANA rats

Ethanol preference and behavioral disinhibition in AA (alcohol accepting) a nimals is a behavioral constellation similar to that seen in human type II alcoholism, for which considerable genetic loading has been shown. In searc h of novel neural substrates for this phenotype, we compared gene expressio n in the cerebral cortex of the AA rat with two groups of control animals, the ANA (alcohol non-accepting) line and heterogeneous Wistar animals, by d ifferential display RT-PCR. We identified two transcripts, ribosomal protei n L18a mRNA and diacyglycerol kinase iota mRNA, which are differentially ex pressed between AA and ANA rats. Ribosomal protein L18A mRNA is evenly expr essed throughout the brain, but strongly reduced in cortex of AA rats vs co ntrols, Diacylglycerol kinase iota is exclusively found in the brain, and e xpressed in a distinct regional pattern. Its cortical expression is about 2 5% higher in AA than ANA rats. Differential display RT-PCR seems to provide a feasible strategy to identify previously unknown genes whose differentia l expression correlates with behavioral phenotypes related to dependence.