We study mechanisms of gene expression and regulation using computational and experimental approaches. We also develop algorithms for the identification of genes in genomic sequences and other applications in genomics. A unifying goal of our research is to understand the rules of RNA splicing specificity: how the precise locations of introns and splice sites are identified in primary transcripts. A major current effort is to develop computational methods to identify splicing enhancer and repressor motifs and to test the function of these motifs using in vivo splicing assays. We continue to develop improved methods for identifying genes in eukaryotic genomes, and we have started to work on computational methods for identifying microRNAs and predicting their functions. We are also using a combination of computational and experimental methods to study alternative splicing, a common mechanism of gene regulation in vertebrates.