Anthropologists at Emory University scanned the whole methylome instead of looking only for inherited DNA changes. The methylome records DNA methylation, an epigenetic mark that can change gene expression in response to the environment. The study was published in Environmental Epigenetics.
The team compared data from 39 individuals in two Indigenous populations: the Kichwa from the Andean highlands of Ecuador and the Ashaninka from the lowland Amazon Basin near the Peruvian border. This is the first whole methylome data for these groups, and it covered many more sites than typical studies.
Analysis showed strong methylation differences in genes such as PSMA8 and FST, and in genes in the P13K/AKT pathway. The authors propose these changes may relate to greater muscularization of small arteries, higher blood viscosity, and a higher rates of pulmonary hypertension reported in Andean highlanders. They also note that epigenetic marks can be flexible, yet the Kichwa had lived in the highlands for nearly 10,000 years, so epigenetics might contribute to long-term adaptation.
Difficult words
- methylome — Complete set of methylation marks on DNA
- methylation — Chemical addition to DNA that affects gene activityDNA methylation, methylation differences
- epigenetic mark — Chemical signal on DNA or proteins changing gene activityepigenetic marks
- gene expression — Process of making a gene's product, like protein
- indigenous population — Group of people native to a particular regionIndigenous populations
- muscularization — Increase in muscle tissue of an organ or vessel
- blood viscosity — Thickness or resistance to flow of blood
- pulmonary hypertension — High blood pressure in blood vessels of the lungs
- adaptation — Change that helps organisms live better in conditionslong-term adaptation
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Discussion questions
- How could flexible epigenetic marks help people who move to a new environment? Give one or two examples.
- Why is it important that this study used whole methylome data for these Indigenous groups?
- Do you think epigenetic changes are more likely to be short-term responses or part of long-term adaptation? Explain your view.
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