Identification of specificityH-2.7 as an erythrocyte antigen: Control by an independent locus,H-2G,between theS andD regions

SpecificityH-2.7 is expressed predominantly on erythrocytes and controlled by a gene that maps within theH-2 gene complex at a locus, designated asH-2G, which apparently lies between regionsS andD. Three phenotypes have been observed with respect to this antigen: a) positive by direct test and absorption (haplotypesH-2^f,H-2^j,H-2^p,H-2^s); b) positive only by absorption (H-2^k); and c) negative (H-2^b,H-2^d,H-2^q). New crossover positions have been established for severalH-2 recombinants based on classifications for theH-2G locus.