Experiment
As a first step towards mapping Rmp4, authors identified the autosomal regions of D2.B6-Rmp4 mice that were of C57BL/6NCr origin (C57BL/6NCr is a mouse strain which is resistant to ectromelia virus). They selected a panel of 422 provisionally mapped informative Mit microsatellite markers dispersed throughout the 19 autosomes, and found that all of the microsatellites in the D2.B6-Rmp4 mice were of DBA/2NCr origin except for five consecutive Mit microsatellites (D1Mit140, D1Mit33, D1Mit106, D1Mit57 and D1Mit110) spanning a distance of 9.1 cM on distal mouse Chromosome 1 which were of C57BL/6NCr origin. In this manner the authors were able to map the gene responsible for ectromelia virus resistance in C57BL/6NCr to the distal part of mouse Chromosome 1. Potential candidate genes for Rmp4 include Cfh (74.1 cM), Sell (86.6 cM), Fcgr2b (92.3 cM), Ly9 (93.3 cM), Cd48 (93.3 cM), Apcs (94.2 cM), and Ifi203 (95.31 cM).