Functional genomics in Caenorhabditis elegans: An approach involving comparisons of sequences from related nematodes

Comparative genomic analysis was used to investigate the gene structure of the bli-4 Locus from two related Caenorhabditis species, C. elegans and C, briggsae. In C. elegans, bli-4 is a complex gene encoding a member of the k ex2/subtilisin-like Family of proprotein convertases. Genomic sequence comp arisons coupled with RT-PCR analysis identified five additional coding exon s that had not been identified previously using standard recombinant DNA te chniques. The C. briggsae gene was able to rescue both viable blistered and developmentally arrested mutants of C. elegans bli-4, demonstrating functi onal conservation. In addition, deletion analysis of conserved sequences ou tside of coding regions, combined with phenotypic rescue experiments, ident ified regulatory elements that alter the expression of the bli-4 gene. Thes e results demonstrate the utility of genomic sequence comparisons of homolo gous genes in related species as an effective tool with which to dissect th e functional information of complex genes.