Determination of exon-intron structure: a novel application of the polymerase chain reaction technique.

We describe a novel application of the polymerase chain reaction (PCR) technique of DNA amplification to study the exon-intron structure of the rat plasminogen activator inhibitor (PAI-1) gene. This technique is relatively simple and also allows the isolation of introns for sequencing. Primers were selected based on a knowledge of the cDNA sequences of human and rat PAI-1 and of the gene structure of human PAI-1. However, knowledge of a cDNA sequence and/or the structure of a gene in another species is not a prerequisite. Sequences selected from positions along the cDNA of interest could be used to amplify the DNA either from an isolated but uncharacterized gene or directly from genomic DNA, making this technique generally applicable. Thus, this method is a useful advance in the study of gene structure and evolution.