PHYSICAL MAPPING OF THE RAT MHC CLASS-II GENES SHOWS A HIGH-LEVEL OF INTERSPECIES CONSERVATION

We report here a pulsed-held gel electrophoresis map of the rat major histocompatibility complex (MHC) class II region. Using probes for the recently discovered Tap-1 and Tap 8 genes and the different MHC class II genes, we found the gene order in the rat MHC (RT1) region to be R T1.H-Tap-1-Tap-2-Bb-Ba-Db-De. Moreover, the distance between the Tap-1 and the RT1.Da genes is approximately 150 kb. This, together with rec ent mapping of the RT1 class III region, demonstrates an extensive col inearity in the MHC region of different species. (C) 1994 Academic Pre ss, Inc.