THE IMMUNOGLOBULIN-LAMBDA-LIKE GENE-CLUSTER (14.1, 16.1, AND F-LAMBDA-1) CONTAINS GENE(S) SELECTIVELY EXPRESSED IN PRE-B CELLS AND IS THE HUMAN COUNTERPART OF THE MOUSE LAMBDA-5 GENE

A human immunoglobulin (Ig)-related gene, covering -8 kb, was Isolated from a cosmid genomic library, by hybridization with a Cλ probe and with a λ-like probe. This gene was Identified as 14.1. It belongs to the human λ-like cluster which is composed of three genes (14.1, 16.1 and Fλ1) that do not rearrange. Sequence data indicate that 14.1 is organized similarly to the mouse λ5 gene. It contains three exons with lengths of 69, 38, and 106 codons as compared with 65, 38, and 106 for exons 1, 2, and 3 of mouse λ5, respectively. The corresponding homology values were 61, 66 and 75.5%. Using a 14.1 specific probe containing exon 1, we showed that this gene was selectively expressed in human pre-B cell lines. It is likely to encode a 213-amlno acid λ-like light chain that would associate with μ chains and play an Important role in the early steps of B cell differentiation. © 1990 Oxford University Press.