Abstract
Native American populations have a limited HLA polymorphism compared with other ethnic groups. In spite of this, many novel HLA-B locus alleles, not observed in other populations, have been identified in South American tribes, and rapid evolution of this locus has been suggested. We have studied unrelated subjects of the Toba (TOB n = 116), Wichi (WIC n = 46) and Pilaga (PIL n = 14) tribes from northeastern Argentina to investigate the extent of the HLA polymorphism and obtain clues of selective forces that may have acted in these populations. In these tribes the number of HLA alleles is small at all loci except HLA-B, which presents 22 alleles. Seven novel alleles were characterized including 5 of HLA-B (B(*)35092, B(*)35l8, B(*)3519, B(*)4009, B(*)4803) 1 at HLA-A (A(*)0219) and 1 at DRB1 (DRB1(*)0417). All these variants may have arisen by gene conversion events. Some of the novel variants represent the most frequent alleles of these populations (B(*)4803 in TOB and PIL; B(*)3519 in WIC) or are the most frequent subtypes in their lineages. HLA-A, B, DRB1, DQA1 and DQB1, but not DPB1, display relatively similar gene frequencies. This results in high heterozygosity in all the tribes for all the loci studied except HLA-DPB1. The larger polymorphism and the generation and maintenance of novel alleles at the HLA-B locus suggests a more specialized response of this locus to evolutionary forces. These effects may be related to the nature of the polymorphism, to the number of founder alleles and to the functional characteristics of the individual alleles.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 233-250 |
| Number of pages | 18 |
| Journal | Tissue Antigens |
| Volume | 50 |
| Issue number | 3 |
| State | Published - 1997 |
Fingerprint
Keywords
- A-locus
- B-locus
- G51152
- HLA class II
- South America
ASJC Scopus subject areas
- Immunology
- Cell Biology
Cite this
Dissimilar evolution of B-locus versus A-locus and class II loci of the HLA region in South American Indian tribes. / Fernández-Viña, M. A.; Lázaro, A. M.; Marcos, C. Y.; Nulf, C.; Raimondi, E.; Haas, E. J.; Stastny, Peter.
In: Tissue Antigens, Vol. 50, No. 3, 1997, p. 233-250.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Dissimilar evolution of B-locus versus A-locus and class II loci of the HLA region in South American Indian tribes
AU - Fernández-Viña, M. A.
AU - Lázaro, A. M.
AU - Marcos, C. Y.
AU - Nulf, C.
AU - Raimondi, E.
AU - Haas, E. J.
AU - Stastny, Peter
PY - 1997
Y1 - 1997
N2 - Native American populations have a limited HLA polymorphism compared with other ethnic groups. In spite of this, many novel HLA-B locus alleles, not observed in other populations, have been identified in South American tribes, and rapid evolution of this locus has been suggested. We have studied unrelated subjects of the Toba (TOB n = 116), Wichi (WIC n = 46) and Pilaga (PIL n = 14) tribes from northeastern Argentina to investigate the extent of the HLA polymorphism and obtain clues of selective forces that may have acted in these populations. In these tribes the number of HLA alleles is small at all loci except HLA-B, which presents 22 alleles. Seven novel alleles were characterized including 5 of HLA-B (B(*)35092, B(*)35l8, B(*)3519, B(*)4009, B(*)4803) 1 at HLA-A (A(*)0219) and 1 at DRB1 (DRB1(*)0417). All these variants may have arisen by gene conversion events. Some of the novel variants represent the most frequent alleles of these populations (B(*)4803 in TOB and PIL; B(*)3519 in WIC) or are the most frequent subtypes in their lineages. HLA-A, B, DRB1, DQA1 and DQB1, but not DPB1, display relatively similar gene frequencies. This results in high heterozygosity in all the tribes for all the loci studied except HLA-DPB1. The larger polymorphism and the generation and maintenance of novel alleles at the HLA-B locus suggests a more specialized response of this locus to evolutionary forces. These effects may be related to the nature of the polymorphism, to the number of founder alleles and to the functional characteristics of the individual alleles.
AB - Native American populations have a limited HLA polymorphism compared with other ethnic groups. In spite of this, many novel HLA-B locus alleles, not observed in other populations, have been identified in South American tribes, and rapid evolution of this locus has been suggested. We have studied unrelated subjects of the Toba (TOB n = 116), Wichi (WIC n = 46) and Pilaga (PIL n = 14) tribes from northeastern Argentina to investigate the extent of the HLA polymorphism and obtain clues of selective forces that may have acted in these populations. In these tribes the number of HLA alleles is small at all loci except HLA-B, which presents 22 alleles. Seven novel alleles were characterized including 5 of HLA-B (B(*)35092, B(*)35l8, B(*)3519, B(*)4009, B(*)4803) 1 at HLA-A (A(*)0219) and 1 at DRB1 (DRB1(*)0417). All these variants may have arisen by gene conversion events. Some of the novel variants represent the most frequent alleles of these populations (B(*)4803 in TOB and PIL; B(*)3519 in WIC) or are the most frequent subtypes in their lineages. HLA-A, B, DRB1, DQA1 and DQB1, but not DPB1, display relatively similar gene frequencies. This results in high heterozygosity in all the tribes for all the loci studied except HLA-DPB1. The larger polymorphism and the generation and maintenance of novel alleles at the HLA-B locus suggests a more specialized response of this locus to evolutionary forces. These effects may be related to the nature of the polymorphism, to the number of founder alleles and to the functional characteristics of the individual alleles.
KW - A-locus
KW - B-locus
KW - G51152
KW - HLA class II
KW - South America
UR - http://www.scopus.com/inward/record.url?scp=0030853136&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030853136&partnerID=8YFLogxK
M3 - Article
C2 - 9331946
AN - SCOPUS:0030853136
VL - 50
SP - 233
EP - 250
JO - HLA
JF - HLA
SN - 2059-2302
IS - 3
ER -