Coding DNA sequence (CDS) and polypeptide diversity of the MHC region. (A) Combined incidence (%) of non-reference CDS alleles through the MHC region of the 95 cell lines. The values are calculated from the homozygous segments only. (B,C) Number of unique coding-sequences (CDS alleles) for each of the expressed genes in the target MHC region detected from analysis of cell lines derived from homozygous individuals. (B) In red are the CDS alleles that encode unique polypeptide sequences, and in blue are additional alleles having synonymous changes. HSPA1 represents three heat-shock protein genes: HSPA1L, HSPA1A, and HSPA1B. MUC22 is the only gene to have more alleles than HLA-B. (C) Total number of CDS alleles corrected for the size of the transcript. Classical HLA genes are indicated in red text. Other polymorphic genes mentioned in the main text are indicated in B; full list of the CDS and alleles is given in Supplemental Table S3. (D) Mean pairwise difference between polypeptide sequences of the unique allotypes expressed by each of the genes in the MHC genomic region.
