FIG. 4.

(A) Feline chromosome C2 confers susceptibility to FPV infection on feline-mouse hybrid cells. Members of a panel of feline-mouse somatic cell hybrids with known feline karyotypes were inoculated with FPV, and the presence of replicating viral DNA was assayed 48 h later. The discordancy between the presence of each feline chromosome and the susceptibility of the hybrid cells to virus infection is shown. (B) Radiation hybrid mapping of the feline TfR gene (TFRC) in a panel of feline-mouse radiation hybrids. The corresponding human chromosome 3 and 21 segments aligned to the right are derived from the Genebridge-4-based maps in the Gene Map '99 radiation hybrid map database (www.ncbi.nlm.nih.gov/genemap). Numbers at the ends of each human conserved segment represent map positions of the most distal markers. A scale bar is shown to the lower right (cR, centiray).