Sequence-ready BAC contig, physical, and transcriptional map of a 2-Mb region overlapping the mouse chromosome 6 host-resistance locus Cmv1

The host-resistance locus Cmv1 controls viral replication of mouse cytomega lovirus (MCMV) in the spleen of infected mice. Cmv1 maps on distal chromoso me 6, very tightly linked to the Ly49 gene family within a 0.35-cM interval defined proximally by Cd94/Nkg2d and distally by D6Mit13/D6Mit111/ D6Mit21 9/Prp/Kap. To facilitate the cloning of the gene, we have created a high-re solution physical map of the Cmv1 genetic interval that is based on long-ra nge restriction mapping by pulsed-field gel electrophoresis, fluorescence f it situ hybridization analysis of interphase nuclei, and the assembly of a cloned contig. A contig of BAC and YAC clones was assembled using probes de rived from the minimal genetic interval. Individual clones from the region were validated by (1) restriction digest fingerprinting, (2) STS content ma pping, (3) Southern hybridizations, and (4) sequencing and mapping of clone ends. This contig contains 25 YACs anchored by 71 STSs and 73 BACs anchore d by 40 STSs. We also report the cloning of 31 new STSs and 18 new polymorp hic markers. A minimum tiling path was defined that consists of either 4 YA Cs or 13 BACs covering 1.82 Mb between D6Ott8, the closest proximal marker, and D6Ott115, the closest distal marker. Gene distribution in the region i ncludes 14 Ly49 genes as well as 3 new additional transcripts. This high-re solution, sequence-ready BAC contig provides a backbone for the identificat ion of Cmv1 and its relationship with genes involved in innate immunity. (C ) 2000 Academic Press.