Somatic cell hybrid mapping on mouse chromosome 11 (MMU11): assignment of markers relative to two breakpoints in band...

Mouse x rat somatic cell hybrids were generated by fusing mouse cell lines that are heterozygous for reciprocal translocations involving the T42H and T9Ad breakpoints on mouse chromosome 11 (MMU11) to a thymidine kinase-negative (Tk-) rat cell line, RT2Tk-. Selection in HAT medium with geneticin disulfate (G418) resulted in some hybrid clones retaining only one derivative translocation chromosome with that part of MMU11 carrying the Tk-1 locus. Southern blot and PCR analyses of these hybrids were used to map the two breakpoints and 30 markers relative to them. The T42H breakpoint has been localized between Mpo and the Cola-1/Hox-2 cluster of loci and is proximal to the T9Ad breakpoint. The T9Ad breakpoint is proximal to the distal loci Tk-1, Gaa, D11Jkn1, and P4hb. The positions of 14 loci (Hox-2, Cola-1, Rara, Phb, Erba, Rnula-1, D11Pas1, Gfap, D11Mit13, D11Mit11, D11Mit12, Myla, Empb3 and Gh) have been further refined by their localization between the two breakpoints in band D. This study therefore improves the correlation of the genetic and physical maps of MMU11 and extends the known homology between MMU11 and human chromosome 17 (HSA17) by the assignment of three additional HSA17 markers, the profilin gene, Pfn, an anonymous marker, D17s28h, and the Crk oncogene, to above the T42H breakpoint; and the prohibitin gene, Phb, to between the T42H and T9Ad breakpoints in band D on MMU11.