Mutational processes of simple-sequence repeat loci in human populations.
AUTOR(ES)
Di Rienzo, A
RESUMO
Mutational processes of simple sequence repeats (SSRs) in complex genomes are poorly understood. We examined these processes by introducing a two-phase mutation model. In this model, most mutations are single-step changes, but infrequent large jumps in repeat number also occur. We used computer simulations to determine expected values of statistics that reflect frequency distributions of allele size for the two-phase model and two alternatives, the one-step and geometric models. The theoretical expectations for each model were tested by comparison with observed values for 10 SSR loci genotyped in the Sardinian population, whose genetic and demographic histories have been previously reconstructed. The two-phase model provided the best fit to the data for most of these loci in this population. In the analysis we assumed that the loci were neutral and that this population had undergone rapid population growth. Recent observations made for unstable trinucleotide repeats support our suggestion that frequent small changes and rare large changes in repeat number represent two distinct classes of mutation at SSR loci. We genotyped the same 10 loci in Egyptian and sub-Saharan African samples to assess the utility of SSRs for studying the divergence of populations and found that estimates of interpopulation distances from SSRs were similar to those derived from analysis of mitochondrial DNA.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=43536Documentos Relacionados
- Genetic variation in clonal vertebrates detected by simple-sequence DNA fingerprinting.
- Persistence of Tandem Arrays: Implications for Satellite and Simple-Sequence Dnas
- Comparison of the myotonic dystrophy associated CTG repeat in European and Japanese populations.
- Genetics of Natural Populations. Xxxii. Inbreeding and the Mutational and Balanced Genetic Loads in Natural Populations of Drosophila Pseudoobscura
- Distribution of serotypes of human rotavirus in different populations.