Métodos estatísticos aplicados à análise de dados de etiqueta de sequência expressa

• Autor(a) principal: Paula, Fernanda Vital de
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4038
• topic: Biblioteca de cDNA, Inferência bayesiana; MCMC; cDNA library; Bayesian inference; MCMC; CNPQ::CIENCIAS EXATAS E DA TERRA::PROBABILIDADE E ESTATISTICA::ESTATISTICA

Expressed sequence tags (ESTs) surveys are a fundamental tools to identify genes in sequencing studies of various organisms. Given a EST preliminary sample from a certain cDNA library, several prediction statistical problems can arise. Particularly, to calculate the number of genes, Δ (t), which may be discovered in a future EST sample t times larger than the original sample is interesting. This and other ststistics, presented by Susko and Roger (2004), such as coverage and number of necessary readings to discover a new gene are useful for direct sequencing protocols by calculating the degree of redundancy of a cDNA library. This calculation seeks to maximize the obtaining of genes during a EST sequencing, however this is still seen as a costly procedure and adequacy techniques for reducing such costs is of fundamental importance. The present work has as objective to present the theoretical aspects of the methodology proposed by Susko and Roger (2004), to implement computationally the methodology in the free software R and mainly to propose a bayesian approach for estimating Δ (t). All the methodology was applied to two data sets: the first concerns two cDNA libraries from Mastigamoeba balamuthi organism and the second concerns two cDNA libraries from skin of F2 (Holstein × Gyr) bovine infested with the ticks Riphicephalus (Boophilus) microplus. For both data sets the interval estimates obtained for Δ (t) were significantly more accurate when the Bayesian inference was used, indicating that it is an aviable alternative for studies related to the calculation of the redundancy in analysis of ESTs.