HIGH-RESOLUTION LINKAGE MAP IN THE PROXIMITY OF THE HOST-RESISTANCE LOCUS CMV1

The mouse chromosome 6 locus Cmv1 controls replication of mouse Cytome galovirus (MCMV) in the spleen of the infected host. In our effort to clone Cmv1, we have constructed a high-resolution genetic linkage map in the proximity of the gene. For this, a total of 45 DNA markers corr esponding to either cloned genes or microsatellites were mapped within a 7.9-cM interval overlapping the Cmv1 region. We have followed the c osegregation of these markers with respect to Cmv1 in a total of 2248 backcross mice from a preexisting interspecific backcross panel of 281 (Mus spretus x C57BL/6J)F1 x C57BL/6J and 2 novel panels of 989 (A/J x C57BL6)F1 x A/J and 978 (BALB/c x C57BL/6J)F1 x BALB/c segregating C mv1. Combined pedigree analysis allowed us to determine the following gene order and intergene distances (in cM) on the distal region of mou se chromosome 6: 3)-Tel/D6Mit374/290/220/196/195/110-(1.1)-D6Mit25. Th erefore, the minimal genetic interval for Cmv1 of 0.7 cM is defined by 13 tightly linked markers including 2 markers, Ly49A and D6Mit370, th at did not show recombination with Cmv1 in 1967 meioses analyzed; the proximal limit of the Cmv1 domain was defined by 8 crossovers between Nkrp1/D6Mit61/135/257/289/338 and Cmv1/Ly49A/D6Mit370, and the distal limit was defined by 5 crossovers between Cmv1/Ly49A/D6Mit370 and Prp/ Kap/D6Mit13/111/219. This work demonstrates tight linkage between Cmv1 and genes from the natural killer complex (NKC), such as Nkrp1 and Ly 49A, suggesting that Cmv1 may represent an NK cell recognition structu re encoded in the NRC region. (C) 1997 Academic Press