Wednesday, February 12, 2014

Black Death Left A Mark On Human Genome

Recent studies of the human genome have found that people who's ancestors were exposed to the Black Plague have a change in their genome. Mihai Netea, an immunologist at Radboud University Nijmegen Medical Centre in the Netherlands, and evolutionary biologist Jaume Bertranpetit of Pompeu Fabra University in Barcelona, Spain, and their colleagues looked for differences at more than 196,000 places in the genomes of 100 Romanians of European descent and 100 Rroma. The researchers also cataloged the differences in 500 people who lived in Northwestern India, where the Rroma had come from. Next, they analyzed which genes changed the most so they could see which were favored by selection.

 
The research was done to figure out why some Europeans respond to different diseases and have different susceptibilities. A thousand years ago, Rroma people (commonly called gypsies) migrated from North India to Europe. They still have very different genetic backgrounds, as they did not often marry outside of their race. However, both of these groups were hit by the Black Plague. Researchers went looking for genes that were favored by natural selection by finding similarities in the Rroma people and in European Romanians that are not found in Northern Indians. 

What they found were 20 genes in the Rroma and Romanians that could not be found in Indian's genes. The genes included skin pigmentation, inflammation, autoimmune diseases, and three immune system genes that can be found on chromosome 4. They code toll-like receptors, and are thought to be directly related with the Black Plague because when they were tested with Yersinia Pestis, they found that the strength of the response had to do with the receptor genes.

Other Europeans who's ancestors have been exposed to the Black Plague do have similar changes. But people who are from places that were not reached by the disease, such as China, do not show these changes. This shows how the Black Death bacterium does change the protein coded for certain genes and has a lasting effect on the population.

This relates to our work in class because we studied the Black Death and what it did to the population during that time period, but now we know the long term effects on people during the present day. Those these changes in genes may not be major, they are significant and a big step in research on disease. These discoveries will probably prompt other labs to see if other bacterial infections could also alter peoples genetic makeup.

http://news.sciencemag.org/biology/2014/02/black-death-left-mark-human-genome

4 comments:

  1. I found this article very interesting because I was unaware that people whose ancestors had the Black Plague had a change in their genome. This relates to the Black Plague unit we did and the bacteria Yersinia Pestis. The article also stated that natural selection played a role. In biology, I learned about Darwin's theory of natural selection. The researchers found 20 genes in the Rroma and Romanians that weren't found in Indian's genes. It is very interesting that researchers are still trying to unveil the science behind the plague that occurred hundreds of years ago. The fact that they may have found something significant is amazing because it could lead to other findings.

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  2. This is a really interesting article, and well summarized. I think I saw a documentary about something similar, where they investigated the inhabitants of a town who were immune to Plague, or something like that. Anyway, this is a cool instance of evolution in humans. Also, I could be mistaken, but wasn't China affected during the Black Plague? I'm probably just misremembering, but maybe it just didn't hit China as hard as Europe to have an effect on people's DNA there.

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  3. Jona, this write up was really well done and interesting! I had no idea that a disease, like the Black Plague could change your genome. This article definitely relates to our class since the Black Plague was a unit we spent quite a bit of time on in class. I really enjoyed reading your article and learned a lot. I would love to look into this topic even more since like I said I had no idea a disease could change your genome. It makes me wonder if other diseases have that ability as well?!

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  4. I think you did a nice job summarizing the article and making it interesting to read. I also agree with Hadley because I had no idea that if an ancestor of yours had the Plague, it would have the ability to affect your genome. I think it would have been interesting to learn more about this in class because who knows what else can be effected. I wonder if there were any other places around the world that has this happening? I also wonder if any other disease have the same affect as well. If so, is there anything we can do?

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