1 / 10

Did sex with Neanderthals and denisovans shape our immune system? Group b8

Did sex with Neanderthals and denisovans shape our immune system? Group b8. Rebecca Hollman, Colleen Adam, Chang-Gun An . Evolutionary Background. Two archaic human groups, Neanderthals and Denisovans - both migrated out of Africa ~400,000 years ago

arch
Download Presentation

Did sex with Neanderthals and denisovans shape our immune system? Group b8

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Did sex with Neanderthals and denisovans shape our immune system?Group b8 Rebecca Hollman, Colleen Adam, Chang-Gun An

  2. Evolutionary Background • Two archaic human groups, Neanderthals and Denisovans- both migrated out of Africa ~400,000 years ago • Neanderthals migrated northwestward into West Asia and Europe • Denisovans migrated northeastward into East Asia • Ancestors of modern day humans migrated out of Africa ~65,000 years ago to both places and began interbreeding

  3. Recombination • Genetic recombination is any change in the combination of alleles on a given chromosome • DNA recombination can produce 200 X 8262 = 1,652,400 different antigen-specific B-Cell and T-Cell receptors • Due to gene recombination, each B-Cell receptor, antibody and T-Cell receptor has a unique amino acid sequence- enabling it to bind a unique epitope on an antigen

  4. Haplotype • A haplotype is a group of genes, inherited together by an organism from a single parent • It is a result of DNA recombination • Contains for every sequence in the genotype, two haplotype sequences that are compatible with the genotype sequence • Haplotypes can be used to trace migrations in the human population since they are so unique (one passed on from the mother and one from the father)

  5. HLA-A,-B,-C • HLA (Human Leukocyte Antigen) helps against infectious disease • Plays a protective role in recognizing cancer cells • An example of an HLA haplotype is HLA-B*73:01 • HLA genes are some of the most variable and adaptable genes in our genome, in part because the rapid evolution of viruses demands felixibility on the part of our immune system

  6. How do we know HLA genes came from archaic humans? • Genotype sequencing showed that up to 6% of archaic DNA is in the modern day human genome • “Within one class of HLA gene, the researchers estimate that Europeans owe half of their variants to interbreeding…” (Parham, 1) • Because of interbreeding and have variability on the HLA gene, modern day humans have stronger immunity to diseases prominent in their geographic location

  7. Discussion • Modern day humans acquired HLA genes, which were dominant immune-related genes, and were more likely to survive local pathogens in Europe, Asia and Oceania • For small migrating populations, interbreeding with archaic humans could restore HLA diversity after population bottleneck and also provide a rapid way to acquire new HLA variants already adapted to local pathogens- increasing survival and haplotype diversity

  8. Conclusions and Take Home Message • In summary, interbreeding between archaic humans and ancestors of modern day humans gave modern human populations more variable and favorable HLA genes- therefore increasing the strength of the modern day immune system • So the reason you’re not constantly sick is that your ancestors decided to get it on with different species

  9. Works Cited • Parham, Peter. "The Shaping of Modern Human Immune Systems by Multiregional Admixture with Archaic Humans." The Shaping of Modern Human Immune Systems by Multiregional Admixture with Archaic Humans. Science Magazine, 25 Aug. 2011. Web. 19 Nov. 2012. <http://www.sciencemag.org/content/ 334/6052/89>. • Young, Susan L. "Canoodling with Cavemen Gave Healthy Boost to Human Genome, Study Finds." Stanford School of Medicine. Stanford University Medical Center, 25 Aug. 2011. Web. 19 Nov. 2012. <http://med.stanford.edu/ism/2011/august/ caveman.html>. • McGrath, Matt. "Neanderthal Sex Boosted Immunity in Modern Humans." BBC News. BBC, 26 Aug. 2011. Web. 19 Nov. 2012. <http://www.bbc.co.uk/news/science- environment-14673047>.

More Related