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HLA in anthropology: The enigma of Easter Island

HLA in anthropology: The enigma of Easter Island. Erik Thorsby Department of Immunology University of Oslo Norway. LA 250114. The HLA class I and II genes are extremely polymorphic > 10.000 alleles are presently known!.

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HLA in anthropology: The enigma of Easter Island

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  1. HLA in anthropology:The enigma of Easter Island Erik Thorsby Department of Immunology University of Oslo Norway LA 250114

  2. The HLA class I and II genes are extremely polymorphic> 10.000 alleles are presently known! Class II genes Class I genes B DP DQ DR C A Series Haplotype (from mother) Haplotype (from father) Gene loci B1 A1 B1 B C A A1 A B1 248 37 509 51 1411 7 3186 2132 2495 Known alleles (2013)

  3. The enigma of Easter Island: Where did the first inhabitants come from?

  4. ~5500 bp ~3500 bp Polynesia . ~3000 bp Easter Island ~1000 bp

  5. But also evidence of an early ”prehistoric” contact between Easter Island and South America • The Andean sweet potato was cultured on Easter Island long before it was discovered by Europeans • Similarities between old fishing gear and other artifacts from eastern Polynesia and the coast of Chile • Linguistic evidence • Thor Heyerdahl : + Similarities between the great stone statues (moai) on Easter Island and South America

  6. But also evidence of an early ”prehistoric” contact between Easter Island and South America • The Andean sweet potato was cultured on Easter Island long before it was discovered by Europeans • Similarities between old fishing gear and other artifacts from eastern Polynesia and the coast of Chile • Linguistic evidence • Thor Heyerdahl : + Similarities between the great stone statues (moai) on Easter Island and South AmericaPostulated that Polynesia and Easter Island were first settled by native Americans; Amerindians

  7. Kon-Tiki 1947 Showed that it is possible to sail a balsa raft from South America to Polynesia But later genetic investigations have failed to detect an early contribution of Amerindians to Polynesia

  8. Easter Island1971 Couldserological HLA typingof ”pure” Easter Islanders reveal an Amerindiangeneticcontribution?

  9. Genomic HLA typing of the 1971 samples All investigated individuals had one or two haplotypes with typical Polynesian HLA alleles

  10. Genomic HLA typing of the 1971 samples 2. Some individuals had a haplotype with ”typical” Amerindian HLA alleles; haplotype a

  11. HLA-B*39:05 Based on investigations of more than 66.800 individuals in 497 populations:HLA-B*39:05is a ”typical” Amerindian HLA allele

  12. Genomic HLA typing of the 1971 samples 2. Some individuals had a haplotype with ”typical” Amerindian HLA alleles; haplotype a

  13. The Amerindian haplotype a could be traced back to before 1846 Wife 1PM (1816-1909) Wife 2: MA (1846-1915): Probable source of the amerindianhaplotype a Haplotype a, an AmerindianHLA haplotype

  14. Genomic HLA typing of the 1971 samples 3. Other individuals had another haplotype with ”typical” Amerindian HLA alleles, haplotype b, - may be a recombinantAmerindian/Polynesian haplotype

  15. Genomic HLA typing of the 1971 samples 3. Other individuals had another haplotype with ”typical” Amerindian HLA alleles, haplotype b, - may be a recombinantAmerindian/Polynesian haplotype- was carried by several unrelated indiv.

  16. When were the Amerindian HLA alleles introduced on Easter Island? • Haplotype a: An Amerindian haplotype which could be traced back to before 1846 • Haplotype b: Recombinant Amerindian/Polynesian HLA haplotype, carried by several unrelated individuals • + Other evidence

  17. When were the Amerindian HLA alleles introduced on Easter Island? • Haplotype a: An Amerindian haplotype which could be traced back to before 1846 • Haplotype b: Recombinant Amerindian/Polynesian HLA haplotype, carried by several unrelated individuals • + Other evidence Suggest introduction i prehistoric time

  18. 1 Polynesia ~1000 bp Easter Island

  19. 1 2 ”Kon-Tiki” ? Polynesia ~1000 bp Easter Island

  20. 1 Polynesia ~1000 bp 2 Easter Island

  21. Remains of Polynesian chicken, from ~ 13-1400 (Storey et al. PNAS 2007) 1 Polynesia ~1000 bp 2 Easter Island

  22. Conclusions • The HLA investigations support that the first ihabitants of Easter Island were Polynesians from the west • But the HLA investigations also demonstrate an early contribution by Amerindians from the east • The Amerindians must have arrived prior to 1846; i.e. before the Peruvian slave trades in the 1860s, • - possibly already in prehistoric time, but most likely after the Polynesians came from the west • Thus, genomic HLA typing added new info on Easter Island • To determine when the first Amerindians may have arrived: - genome wide investigations of the collected DNA - investigations of DNA prepared from ancestral bones

  23. Special thanks to: Benedicte A. Lie, Siri T. Flåm Dept. of Medical Genetics, University of Oslo, Norway Erika HagelbergDept. of Biology, University of Oslo, Norway Alicia Sanchez-Mazas Dept. of Anthropology, University of Geneva, Switzerland Marcelo A. Fernandez-VinaDept. of Pathology, Stanford University, USA and Jean Dausset and Anne Thorsby who helped in the selection of the investigated individuals and collection of the blood samples in 1971

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