DELETIONAL MAPPING OF 15 MOUSE V-H GENE FAMILIES REVEALS A COMMON ORGANIZATION FOR 3 IGH HAPLOTYPES

In addition to the content of germ-line variable gene segments, the or ganization of V genes has been implicated in the development of the Ab repertoire, We have searched the expressed V-H genes of BALB/c mice f or additional V-H gene families and utilized deletion mapping to explo re the extent of V-H gene family interspersion. We have identified and characterized one new V-H gene family (V(H)15) acid extended our prev ious studies of the Igh(a) and Igh(b) haplotypes to include a third ha plotype (Igh(j)) using a newly developed panel of pre-B cell lines (CX CB cell lines), We conclude that the Igh(a) Igh(b), and Igh(j) haploty pes have a similar Igh-Vlocus structure, A refined deletional map for 15 V-H gene families and an individual member of the V(H)SM7 family (H 10) has been constructed based on the deletion profiles of 72 rearrang ed heavy chain loci, These results demonstrate previously unrecognized examples of interspersion among members of the V(H)S107, V(H)10, and V(H)SM7 families.