ONE-MEGABASE SEQUENCE-ANALYSIS OF THE HUMAN-IMMUNOGLOBULIN-LAMBDA GENE LOCUS

A total of 1,025,415 bases of nucleotide sequence, including the entir e human immunoglobulin lambda gene locus has been determined. This is the largest contiguous human DNA sequence ever published. The sequence data revealed the organization of 36 potentially active V-lambda gene segments, 33 pseudogene segmnets, and seven J(lambda)-C-lambda. Among these 69 functional or nonfunctional V-lambda gene segments, 32 were newly discovered. These V-lambda gene segments are located within five gene-rich clusters and are divided into five clans based on sequence identity. Five potentially active nonimmunoglobulin genes were also de tected within the lambda gene locus, and two other genes were observed in the upstream region. Sequence organization suggests that large DNA duplications diversified the germ-line repertoire of the V-lambda gen e segments.