The Effect of Mating with Neanderthals and Denisovans on our
Transcript The Effect of Mating with Neanderthals and Denisovans on our
The Effect of Mating with
Neanderthals and Denisovans
on our Immune system
Gerald Duncan, Olivia Lahay, Madeline
Lionberger, Kyle Sledge, Heather Yutko
• HLA (human leukocyte antigen): Genes important in immune
• Haplotype: Combination of alleles transmitted together
• Ligand: binds to receptors
• Natural Killer Cells: Integral part of immune system
• Denisovans: group similar to Neanderthals
• Balancing selection: Multiple alleles maintained in population
• Introgression: Gene flow between hybrids and parental
• Admixture: Mixing formerly unexposed populations
• Study led by Stanford University
• Human migration from Africa occurred 67,500 years ago
• Maximum of 4% of modern Eurasian genomes can be traced
back to Neanderthals
• Maximum of 4-6% of modern Melanesian genomes can be
traced back to Denisovans
• Thousands of alleles per HLA
Model of a HLA-B Protein
• Percentage of HLA-A deviations believed (Abi-Rached) to be
from sexual activity with extinct races:
I. European: 50%
II. Chinese: 70%
III. Papua New Guinean: 95%
• 50-60 % of Chinese inhabitants possess A*11
• Very rare in African regions
• The findings suggest:
Interbreeding between archaic humans and Homo
Adaptive introgression of HLA genes.
Control NK cells
T cell immunity
Highly polymorphic---different alleles
Vital immune system component
Some HLA alleles in modern humans may have
originated from extinct human species.
These alleles may contribute to defending against
locally prevalent diseases.
Abi-Rached, Jobin, Kulkami, McWhinnie, Dalva, Gragert, Babrzadeh, Gharizadeh, Luo, Plummer, Kimani, Carrington,
Middleton, Rajalingam, Beksac, Marsh, Maiers, Guethlein, Tavoularis, Little, Green, Norman & Parham. 2011.
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