Genetic variation of the second exon of ELA-DRB genes in Argentine Creole horses

DIAZ, S.; GIOVAMBATTISTA, G.; DULOUT, F. N.; PERAL GARCÍA, P.

ANIMAL GENETICS

WILEY-BLACKWELL PUBLISHING, INC

Año: 2001 vol. 32 p. 257 - 263

0268-9146

Genetic variation in the equine leucocyte antigen-DRB (ELA-DRB) second exon was investigated using polymerase chain reaction (PCR) ampli®cation, restriction fragment length polymorphism (RFLP) of PCR products (PCR-RFLP) and deoxyribonucleic acid (DNA) sequencing. Eight distinct PCR-RFLP patterns could be identi®ed in the studied Argentine Creole (AC) horses. The number of observed patterns per individual ranged from four to six, thus con®rming the presence of multiple DRB copies in AC horses. Three PCR-RFLP alleles and three new sequences were identi®ed. The estimated rates of synonymous and non-synonymous substitutions among ELA-DRB exon 2 sequences were higher within the antigen recognition site (ABS) than on the non-ABS. Phylogenetic analysis showed that the nucleotide sequences clustered in two main groups, while some sequences were not included in either group. Finally, the identi®cation of the number of alleles per animal, the phylogenetic and segregation analyses allowed us to explain the number of ELA-DRB loci. However, it was not possible to identify speci®c alleles with speci®c loci.DRB (ELA-DRB) second exon was investigated using polymerase chain reaction (PCR) ampli®cation, restriction fragment length polymorphism (RFLP) of PCR products (PCR-RFLP) and deoxyribonucleic acid (DNA) sequencing. Eight distinct PCR-RFLP patterns could be identi®ed in the studied Argentine Creole (AC) horses. The number of observed patterns per individual ranged from four to six, thus con®rming the presence of multiple DRB copies in AC horses. Three PCR-RFLP alleles and three new sequences were identi®ed. The estimated rates of synonymous and non-synonymous substitutions among ELA-DRB exon 2 sequences were higher within the antigen recognition site (ABS) than on the non-ABS. Phylogenetic analysis showed that the nucleotide sequences clustered in two main groups, while some sequences were not included in either group. Finally, the identi®cation of the number of alleles per animal, the phylogenetic and segregation analyses allowed us to explain the number of ELA-DRB loci. However, it was not possible to identify speci®c alleles with speci®c loci.