The immunoglobulin light chain locus of the turkey, Meleagris gallopavo

To date, most jawed vertebrate species encode more than one immunoglobulin light (IgL) chain isotypes. It has been shown that several bird species (chickens, white Pekin or domestic duck, and zebra finches) exclusively express lambda isotype. We analyze here the genomic organization of another bird species turkey IgL genes based on the recently released genome data. The turkey IgL locus located on chromosome 17 spans approximately 75.2 kb and contains a single functional Vλ gene, twenty Vλ pseudogenes, and a single functional Jλ-Cλ block. These data suggest that the genomic organization of bird IgL chain genes seems to be conserved. Ten cDNA clones from turkey Igλ chain containing almost full-length Vλ, Jλ and Cλ segments were acquired. The comparison of Vλ cDNA sequences to all the germline Vλ segments suggests that turkey species may be generating IgL chain diversity by gene conversion and somatic hypermutation like the chicken. This study provides insights into the immunoglobulin light chain genes in another bird species.