The new recombinant haplotypes r19 and r20 in RT1, the MHC of the rat.

ABSTRACT

Two new recombinants, designated r19 and r20, have been found in RT1, the rat major histocompatibility complex. In both recombinants the A and I regions appear to be derived from one parental haplotype, and a further region, able to induce both skin graft rejection and cytotoxic lymphocytes is derived from the other. The properties of this region appear similar to the previously described RT1C and the putative genotypes of the PVG X R19 and PVG X R20 congenic lines are therefore AaIaCc and AcIcCa, respectively. Evidence suggesting that the two recombinants may not be reciprocal is discussed.