Comparative mapping of IGHG1, IGHM, FES, and FOS in domestic cattle.

The immunoglobulin genes have not been genetically characterized as thoroughly in cattle as in other mammals, particularly humans and mice. Comparative gene mapping in mammals suggests that the bovine immunoglobulin heavy chain genes, IGHG4 and IGHM might be syntenic with the FOS oncogene. Interestingly, however, when these genes were assigned to bovine syntenic groups utilizing a panel of bovine: hamster hybrid somatic cells, IGH genes were shown to be syntenic with the FES oncogene rather than FOS. In this study IGH and FES were assigned to Bos taurus chromosome 21 while FOS was assigned to chromosome 10. In addition, bovine-specific immunoglobulin-like sequences were observed in the hybrid somatic cells, and one, IGHML1, was mapped to bovine syntenic group U16. The probes used for somatic-cell mapping were also used to screen a small number of cattle of several different breeds for restriction fragment length polymorphisms. IGHG4 and IGHM were shown to be highly polymorphic, while FOS and FES were not.