Nelson Frazão, PhD.
After graduating in Biology from Universidade de Lisboa in 2002, Nelson joined the Instituto de Tecnologia Química e Biológica (ITQB). He started his PhD in 2006, having conducted his doctoral work at ITQB, Portugal, The Rockefeller University, USA, and The Radboud Institute for Health Sciences, Netherlands. During his PhD, Nelson studied the impact of specific vaccines against Streptococcus pneumoniae colonizing healthy infants. In 2010 he received his PhD degree in Molecular Biology from Universidade Nova de Lisboa and in 2014 joined the Evolutionary Biology group at the IGC to study the adaptation of Escherichia coli to the mammalian gut.
Phage-mediated HGT is followed by complex clonal evolution. (A and B) Evolution experiment: Muller plots of the adaptive phage-mediatedHGT and mutation dynamics in the invader E. coli population (A, mouse G2; B, mouse H2). Shaded areas are proportional to the frequency of each clone: ancestral (yellow), Nef lysogen (light orange), Nef+KingRac lysogen (darkorange), and de novo mutations frlR (1 nonsynonymous mutation, 2 deletion mutations) in mouse G2 (black) and psuK/fruA(1 intergenic mutation) in mouse H2 (gray). Phage symbols indicate the HGT events (1 refers to Nef and2 to KingRac) for each clone. Numbers in the top row give the estimated number of generations. (C and D) Co-colonization experiment: Muller plots of phage-mediated HGT in new recipient E. coli populations in 2 mice (clones are now shaded in blue). In all cases, HGT takes place first, and de novo mutations appear on the background of high-frequency lysogenic clones.
Horizontal gene transfer overrides mutation in Escherichia coli colonizing the mammalian gut
