Cloning and expression of class I major histocompatibility complex genes of the rat.
Little is known about the organization of class I genes in the rat although there is prima facie evidence that it is distinct from that of the mouse. We report the cloning of 61 nonclassical rat class I genes into cosmid clusters with a total mapped length of 1,264 kb. It is certain that the total number of class I genes in the rat must exceed this number. From restriction maps it is possible to identify substantial regions of duplication. By transfection of cosmids into mouse L cells, it has been possible to demonstrate at least seven different nonclassical rat class I genes that are expressible on the cell surface. Crossreaction of a single mouse monoclonal antibody with all of these class I molecules is consistent with sequence homogenization within the rat nonclassical system. Attempts to find rat homologues of the mouse Tla genes by crosshybridization of rat cosmids with a range of different TLa-specific probes were unsuccessful, suggesting that this large group of divergent class I genes is absent or nearly so from the rat. The large number of class I genes in the rat appears to have arisen by expansion of genes more closely related to the classical sequence.
Jameson
S C
SC
Department of Immunology, Agricultural and Food Research Council Institute of Animal Physiology and Genetics Research, Babraham, Cambridge, England.
Tope
W D
WD
Tredgett
E M
EM
Windle
J M
JM
Diamond
A G
AG
Howard
J C
JC
D000818:Animals; D003001:Cloning, Molecular; D003360:Cosmids; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D015342:DNA Probes; D005091:Exons; D015870:Gene Expression; D015723:Gene Library; D005805:Genes, MHC Class I; D051379:Mice; D051381:Rats; D011919:Rats, Inbred Strains; D015183:Restriction Mapping; D014162:Transfection
D015342:DNA Probes; D004247:DNA