Caracterização da distribuição de alelos de loci STR do cromossomo Y com elevada taxa de mutação em uma amostra populacional do Rio de Janeiro

• Autor(a) principal: Rêgo, Juliana Jannuzzi Duclos do
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/16287
• topic: Y chromosome; Genetic markers; Microsatellites; RM-YSTR; Cromossomo Y; Marcadores genéticos; Microssatélites; RM-YSTR; Cromossomo Y; Marcadores genéticos; Genética de populações; Mutagênese; Polimorfismo (Genética); CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA HUMANA E MEDICA

Genetic markers on Y chromosome, as microsatellites (Y-STRs) and single nucleotide polymorphisms (Y-SNPs) are used for the characterization of male lineages, since they are fully transmitted to next generations unless mutations occurs (Singh et al., 2011; Mitchell & Hammer, 1996; Butler, 2009). Therefore, these markers are widely applied in several situations, highlighting the constant use of Y-STRs in the field of forensic genetics because of their high capacity of discriminate lineages. Recently, 13 rapidly mutating markers were described due to their highly mutation rates in comparison to other common Y-chromosome STRs, being called as Rapidly Mutating Y-STR (RM-YSTR) (Ballantyne et al., 2010; Kayser et al., 2012). As a result of their high mutation rates, RM-YSTRs display high efficiency in discriminating paternally related males. The present work aimed to deepen the knowledge about population and mutational RM-YSTR loci characteristics in Rio de Janeiro sample, and then, contribute to other studies with this purpose in Brazilian population. Y chromosome 13 STRs analysis was realized in 258 males born in Rio de Janeiro state, grouped in 129 fathers/sons pairs. The extraction of DNA from biological samples was performed according to routine protocols from LDD-UERJ. Target sequences were amplified by three polimerase chain reactions (PCR) and the amplicons were separated through electrophoresis on automated sequencer ABI-3500 (Applied Biosystems). When mutations were detected, they were confirmed by sequencing. Among the investigated sample, RM-YSTR loci showed a discrimination capacity of 1,0 which means that all 129 analyzed individuals have different haplotypes for these markers, displaying frequencies of 0,0077 and haplotype diversity of 1,0. Moreover, high values of genetic diversities were obtained for the 13 markers. Distance genetic analysis and AMOVA values based on Fst results did not show population substructure and common ancestral traits. These results are associated with high mutation rates found, with an average rate about 2,11 x 10-2. RM-YSTR showed to be very discriminative at this mixed sample, besides proving to be more discriminative than other markers commonly used in population studies and forensic analysis. Thus, it is possible to conclude that RM-YSTR markers are promising to discriminate individuals of the same male strain and due to their high mutation rates and discrimination capacity, they are able to differentiate individuals better than other common markers. Nevertheless, for a better characterization of these loci in different populations more studies are needed.