Five regional localizations to the sheep genome: first assignments to chromosomes 5 and 12.

The regional localization of five reference loci to sheep chromosomes is reported. The newly mapped loci are the T-cell receptor, beta (TCRB), coagulation factor X (F10), laminin gamma 1 (LAMC1), cyclic GMP rod phosphodiesterase, alpha (PDEA) and fibroblast growth factor 2 (FGF2). The assignments of PDEA and LAMC1 to chromosomes 5q23-q31 and 12q22-q24 respectively provide the first markers physically assigned to these chromosomes. They also allow the provisional assignment of sheep syntenic group U19 to chromosome 5 and U1 to chromosome 12. The mapping of FGF2 to chromosome 17q23-q25 anchors the unassigned linkage group 'A' to chromosome 17, and the assignment of TCRB to chromosome 4q32-qter facilitates the orientation of a linkage group on sheep chromosome 4. The mapping of F10 to sheep chromosome 10q23-qter supports the recent assignment of bovine syntenic group U27 to cattle chromosome 12, as sheep chromosome 10 and cattle chromosome 12 are banded homologues.