Full text
| |
| Author(s): |
Cainã Max Couto da Silva
Total Authors: 1
|
| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2021-04-23 |
| Examining board members: |
Tábita Hünemeier;
Carlos Eduardo Guerra Amorim;
Maria Magdalena Gayà Vidal
|
| Advisor: | Tábita Hünemeier |
| Abstract | |
The American continent was peopled approximately 15,000 years ago.he first Native Americans quickly spread out from North to South America, passing through various distinct ecoregions, including the Amazon rainforest and the Andean highlands. Both regions present challenges to human livelihood. The Amazon rainforest is humid with low solar penetration, high pathogenicity, and periods of scarcity of human food. On the other hand, Andean highlands are known for their low oxygen concentration, intense cold, and high UV radiation intensity. Therefore, native populations from such environments could have genetic variants that favored their subsistence in these enco.. To assess the influence of natural selection in these ecorregions, we used 285 Native South American individuals (222 from lowlands and 63 from highlands). To detect positive selection, we applied either haplotype-based methods, such as iHS and XP-EHH, or methods based on population differentiation via Fst, such as PBS. Furthermore, we used the results of the selection tests to apply gene enrichment tests, in silico eQTL analysis, functional annotation of the candidate genes, demographic simulations, and we carried out a metanalysis from already published data on native populations from tropical forests of different continents. As a result, in the Amazon region, we identified candidate genes and signaling pathways related to energy metabolism, cardiovascular pathways, immune defense, and novelty seeking behavior. In the Andean region, we have identified candidate genes with essential functions to metabolism in stress situations promoted by hypoxia, showing that Andean natives seem to have alternative ways for adapting to the altiplano when compared to other altitude populations from distinct continents. The present work reveals unprecedented data related to the adaptation of Native Americans to two leading ecoregions in the continent, showing that metabolic routes that were previously important to the environment exploration and survival, today play a big role in the epidemiological profile of these populations. (AU) | |
| FAPESP's process: | 17/14916-8 - The role of natural selection on the diversification of Native American populations |
| Grantee: | Cainã Max Couto da Silva |
| Support Opportunities: | Scholarships in Brazil - Doctorate |