The recombinant strain D2.GD was originally typed as I-A(d) by serological methods. Indeed, the A(α) and A(β) chains of the I-A antigens appear to exhibit normal behavior by the criteria of serology and two dimensional gel analysis. However, the E(β) chain encoded by the I-A subregion of this strain, one of the two components of the plasma membrane located I-E antigens produced in (D2.GD x A.TFR5)F1 animals, has been demonstrated to be the product of an intragenic recombinational event between E(β) genes from the d and b haplotypes. Sequence analysis suggests that the amino-terminal portion of the E(β)(g2) chain is derived from the d haplotype and, therefore, that the coding strand for this gene is oriented centromeric → telomeric (5' to 3' direction). Finally, these data combined with the data of Rose and Cullen allow the ordering of the genes within the I-A subregion as (H-2K), A(α), A(β), E(β) ... (H-2D).
ASJC Scopus subject areas
- Immunology and Allergy