Haplotype structures and polymorphisms of dog leukocyte antigen (DLA) class I loci shaped by intralocus and interlocus recombination events

• Published in: Immunogenetics (New York) 2022-04, Vol.74 (2), p.245-259
• Main Authors: Miyamae, Jiro, Okano, Masaharu, Nishiya, Kohei, Katakura, Fumihiko, Kulski, Jerzy K., Moritomo, Tadaaki, Shiina, Takashi
• Format: Article
• Language: English
• Subjects: 5' Untranslated Regions; Alleles; Allergology; Animals; Antigens; Biomedical and Life Sciences; Biomedicine; Cell Biology; Chromosome 12; Conversion; Dog Diseases - genetics; Dogs; Gene conversion; Gene Function; Gene sequencing; Genomics; Haplotypes; Haplotypes - genetics; Histocompatibility Antigens Class I - genetics; Human Genetics; Immunology; Leukocytes; Loci; Nucleotide sequence; Nucleotides; Original Article; Polymorphism, Genetic; Recombination; Recombination, Genetic
• ISSN: 0093-7711; 1432-1211
• DOI: 10.1007/s00251-021-01234-5

The dog leukocyte antigen ( DLA ) class I genomic region is located on chromosome 12, and the class I genomic region is composed of at least two distinct haplotypic gene structures, DLA-88 – DLA-12 and DLA-88–DLA-88L . However, detailed information of the genomic differences among DLA-88 , DLA-12 , and DLA-88L are still lacking at the full-length gene level, and therefore, DLA allelic sequences classified for each of these loci are limited in number so far. In this study, we determined the DNA sequence of a 95-kb DLA class I genomic region including DLA-88 , DLA-12/88L , and DLA-64 with three DLA homozygous dogs and of 37 full-length allelic gene sequences for DLA-88 and DLA-12/88L loci in 26 DLA class I homozygous dogs. Nucleotide diversity profiles of the 95-kb regions and sequence identity scores of the allelic sequences suggested that DLA-88L is a hybrid gene generated by interlocus and/or intralocus gene conversion between DLA-88 and DLA-12. The putative minimum conversion tract was estimated to be at least an 850-bp segment in length located from the 5´flanking untranslated region to the end of intron 2. In addition, at least one DLA-12 allele ( DLA-12*004:01 ) was newly generated by interlocus gene conversion. In conclusion, the analysis for the occurrence of gene conversion within the dog DLA class I region revealed intralocus gene conversion tracts in 17 of 27 DLA-88 alleles and two of 10 DLA-12 alleles, suggesting that intralocus gene conversion has played an important role in expanding DLA allelic variations.