Three classes of mouse H–2 messenger RNA distinguished by analysis of cDNA clones

Abstract

The major histocompatibility complex (MHC) is composed of a set of linked genes encoding proteins involved in the host's immune response¹. A subset of these proteins are the classical transplantation antigens, which are responsible for rapid allograft rejection and are involved in the associative recognition of foreign antigens by cytotoxic T cells^1,2. Three different genetic loci coding for the transplantation antigens in humans (HLA-A, -B and -C) and in mice (H–2K, D and L) have been identified^3,4; they are highly polymorphic¹. The recent molecular cloning of HLA^5,6 and H–2^7,8 cDNA sequences provide the basis for detailed characterization of the genetic organization and expression of the MHC. We report here the identification, by analysis of cDNA clones, of at least three distinct classes of H-2 messenger RNAs that can be differentiated on the basis of their disparate 3′-non-translated regions, and describe an unusual sequence arrangement in one class of H–2-like molecule.