Abstract
Multiple major histocompatibility complex (MHC) alleles exist at most class I and II loci. Polymorphism of MHC polypeptides may reflect either different levels of selective pressure operating on each molecule or different mutation rates at different loci. To gain further insight into this issue, we sequenced the non-coding promoter region of the HLA-DRA gene from several Epstein-Barr virus-transformed B cell lines and compared the extent of polymorphism found in this region with the known polymorphism of the HLA-DQB promoter. Our results indicate that the HLA-DRA promoter displays a low level of polymorphism while the promoter of HLA-DQB exhibits a nucleotide substitution rate fivefold greater than that of DRA. Moreover, through phylogenetic analysis, the HLA-DRA promoter was found to have diverged much less than the associated alleles of HLA-DRB1 and -DQA1. Taken together, these results suggest that the HLA-DRA promoter is highly conserved and may be under a stronger functional constraint than the promoter regions of other MHC class II genes.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 30 May 1996 / Revised: 24 January 1997
Rights and permissions
About this article
Cite this article
Schwiebert, L., Hughes, A., Monos, D. et al. HLA-DRA promoter polymorphism and diversity generation within the immune system. Hum Genet 99, 801–805 (1997). https://doi.org/10.1007/s004390050452
Issue Date:
DOI: https://doi.org/10.1007/s004390050452