In silico cloning of novel endothelial-specific genes

The endothelium plays a pivotal role in many physiological and pathological processes and is known to be an exceptionally active transcriptional site. To advance our understanding of endothelial cell biology and to elucidate potential pharmaceutical targets, we developed a new database screening app roach to permit identification of novel endothelial-specific genes. The Uni Gene gene index was screened using high stringency BLAST against a pool of endothelial expressed sequence taps (ESTs) and a pool of nonendothelial EST s constructed From cell-type-specific dbEST libraries. UniGene clusters wit h matches in the endothelial pool and no matches in the nonendothelial pool were selected. The UniGene/EST approach was then combined with serial anal ysis of gene expression (SAGE) library subtraction and reverse transcriptio n polymerase chain reaction to further examine interesting clusters. Four n ovel genes were identified and labeled: endothelial cell-specific molecules (ECSM) 1-3 and magic roundabout (similar to the axon guidance protein roun dabout). In summary, we present a powerful novel approach for comparative e xpression analysis combining two datamining strategies followed by experime ntal verification.