Chromosomal localization, genomic structure, and allelic polymorphism of the human CD79 alpha (Ig-alpha/mb-1) gene

The germline DNA sequence of the human CD79 alpha (Ig-alpha/mb-1) gene was determined by polymerase chain reaction sequencing of a cosmid clone derived from an arrayed human chromosome 19 library. The CD79 alpha gene was localized to chromosome 19q13.2; this localization places the gene within the CEA-like gene cluster with the following gene order: -CEA-CGM1-CD79 alpha-RPS11-ATP1A3-BGP-CGM9-. The genomic organization of the human CD79 alpha gene resembles the mouse counterpart with five exons interrupted by four introns. Computer analyses suggest the presence of transcription regulatory elements known to be important in the regulation of mouse CD79 alpha (AP-1, EBF, AP-2, MUF2, and SP-1 sites), as well as elements not found in the mouse gene (an NK-kappa B binding site and a series of E-box motifs). Similar to the mouse gene, the 5' flanking region of human CD79 alpha lacks a TATA box; however, unlike mouse CD79 alpha, a classical octamer motif could not be identified in the human gene. Finally, a new Rsa I restriction fragment length polymorphism was defined in the non-coding regions of the human gene.