de Magalhaes J.P.,University of Liverpool |
Matsuda A.,Escola Superior de Biotecnologia |
Matsuda A.,Harvard University
Annals of Human Genetics | Year: 2012
Modern humans originated in Africa before migrating across the world with founder effects and adaptations to new environments contributing to their present phenotypic diversity. Determining the genetic basis of differences between populations may provide clues about our evolutionary history and may have clinical implications. Herein, we develop a method to detect genes and biological processes in which populations most differ by calculating the genetic distance between modern populations and a hypothetical ancestral population. We apply our method to large-scale single nucleotide polymorphism (SNP) data from human populations of African, European and Asian origin. As expected, ancestral alleles were more conserved in the African populations and we found evidence of high divergence in genes previously suggested as targets of selection related to skin pigmentation, immune response, senses and dietary adaptations. Our genome-wide scan also reveals novel candidates for contributing to population-specific traits. These include genes related to neuronal development and behavior that may have been influenced by cultural processes. Moreover, in the African populations, we found a high divergence in genes related to UV protection and to the male reproductive system. Taken together, these results confirm and expand previous findings, providing new clues about the evolution and genetics of human phenotypic diversity. © 2011 The Authors Annals of Human Genetics © 2011 Blackwell Publishing Ltd/University College London.
Amorim L.R.P.,Escola Superior de Biotecnologia |
Tamames J.A.C.,REQUIMTE |
Silva J.G.L.,Escola Superior de Biotecnologia |
Gibbs P.A.,Escola Superior de Biotecnologia |
Teixeira P.C.,Escola Superior de Biotecnologia
Food Control | Year: 2010
This study explored the lytic ability of bacteriophages as a future tool for reducing the Salmonella spp. loads in food animals. It investigated (a) the concept of a phage cocktail resulting from an exploratory analysis of the 13 phages which were examined, and (b) the possibility of using them in phage typing techniques for a broad range of serotypes. By using the conventional plaque assay method and cluster analysis, it was possible to select the 2/2, N5, 2α, 135KP and 12′ phages, as potential elements of a cocktail as a means of efficiently eliminating the greatest number of several types of Salmonella. The 2/2 and N5 phages were also the most efficacious infective elements against the Typhimurium and Enteritidis serovars, respectively. © 2009 Elsevier Ltd. All rights reserved.