A bacterial artificial chromosome (BAC) library was created using partially digested rabbit chromosomal DNA. Four BAC clones spanning about 0.5 Mb of the rabbit immunoglobulin (Ig) heavy chain locus were isolated and sequenced. Three of the BAC clones were partially overlapping. Thirty-four V elements, 11 D elements, DQ52, six J elements and the coding regions of Cmicro, Cgamma, C and four Calpha genes were identified and characterized. Additionally, the sequence of a fosmid clone spanning Calpha13 and 30 kb 3'enhancer region was determined. The organization of the locus and the potential function of newly identified functional and structural elements are discussed.