Serology, restriction fragment length polymorphism, and sequence analysis of a unique HLA class II antigen, DR5x6.
We analyzed a new class II HLA haplotype, which we have designated DR5x6, by serology, restriction fragment length polymorphism (RFLP), and sequence analysis. As the name DR5x6 implies, the antigen is serologically closely related to both DR5 and DRw6. RFLP analysis of this haplotype suggests a close similarity with DRw11 haplotypes. The DNA sequences encoded by the second exon of its DRB1, DRB3, and DQB1 genes were also determined. Comparison of these sequences with those of alleles at these loci in other haplotypes suggests that this haplotype could have evolved from a DRw11 ancestor haplotype (DRw11-DRw52b (Dw25)-DQw7) by means of: (a) a gene conversion at the DRB1 locus involving DRw8 (Dw8.3) as the sequence donor, plus a point mutation or a gene conversion involving DR4-Dw4; and (b) a recombination event by which this haplotype would have acquired the DRw5a (Dw24) allele at the DRB3 locus.
University of Minnesota Immunobiology Research Center, Department of Laboratory Medicine and Pathology, Minneapolis 55455.
H J
HJ
Noreen
P
P
Santamaria
M L
ML
Davidson
S S
SS
Rich
M
M
Segall
D001483:Base Sequence; D005075:Biological Evolution; D004247:DNA / Q000235:genetics; D005785:Gene Conversion; D015805:HLA-DR5 Antigen / Q000235:genetics*; D015808:HLA-DR6 Antigen / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D008969:Molecular Sequence Data; D012150:Polymorphism, Restriction Fragment Length
D015805:HLA-DR5 Antigen; D015808:HLA-DR6 Antigen; D004247:DNA