Full text
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| Author(s): |
Renan Barbosa Lemes
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2013-08-21 |
| Examining board members: |
Paulo Alberto Otto;
Louis Bernard Klaczko;
Diogo Meyer
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| Advisor: | Paulo Alberto Otto |
| Abstract | |
Vale do Ribeira is a region located at the southern part of the state of São Paulo, corresponding to about 10% of its territory. Most of the quilombo remnants of the state are placed inside this region. Using both molecular markers and genealogical data analyses, we estimated population genetic parameters from the communities (breeding system and subestructure organization). Genealogical and molecular data (collected from 2000 and 1000 individuals respectively) were obtained from 13 quilombo communities: Maria Rosa, Pilões, Galvão, São Pedro, Pedro Cubas, Ivaporanduva, Sapatu, André Lopes, Nhunguara, Abobral (both left and right edges), Poça e Reginaldo. Genealogical analysis enabled us to obtain a mean F value of 0.00134, that represents an underestimate of the true value due to lack of reliable genealogical information. Even so, this value is almost 1.5 times higher than the value estimated for the total Brazilian population and almost twice as high than the same parameter estimated for the state of São Paulo. By means of genomic loci data analysis, we obtained mean nF/n value for the quilombo communities separately. Twelve (5%) out of a total of 239 loci from eight communities were in p2:2pq:q2 ratios, as expected by chance; and for the set of all quilombo communities, four (13.33%) out of 30 loci deviated significantly from Hardy-Weinberg ratios, indicating an excess of homozygosis. We also estimated the weighted mean value of F for the whole population by averaging the nF/n values obtained from each locus by the reciprocal of their corresponding variances. For calculating the variance of estimated nF/n values we developed a novel method that can be easily generalized to the case of any number of alleles segregating at an autosomal locus/ No significant levels of population subtructure were detected since the estimated Fst values among populations were in general quite modest. We present also, as attachment to this work, the listings of the main computer program codes we used in our calculations and a section on the evolution of the fixation index F under different systems of regular endogamy. (AU) | |
| FAPESP's process: | 11/16508-8 - Estimation of population genetic parameters in human isolates from Vale do Ribeira, SP ("quilombo" populations) |
| Grantee: | Renan Barbosa Lemes |
| Support Opportunities: | Scholarships in Brazil - Master |