Search results for "Genome Evolution"
showing 5 items of 55 documents
The rise and the fall of a Pseudomonas aeruginosa epidemic lineage in a hospital
2020
AbstractThe biological features that allow a pathogen to survive in the hospital environment are mostly unknown. The extinction of bacterial epidemics in hospitals is mostly attributed to changes in medical practice, including infection control, but the role of bacterial adaptation has never been documented. We analyzed a collection of Pseudomonas aeruginosa isolates belonging to the Besançon Epidemic Strain (BES), responsible for a 12-year nosocomial outbreak, using a genotype-to-phenotype approach. Bayesian analysis estimated the emergence of the clone in the hospital five years before its opening, during the creation of its water distribution network made of copper. BES survived better t…
Genome Instability in DNA Viruses
2016
Genome instability generally refers to the appearance of a high frequency of mutations in a single genome, including point mutations, insertions/deletions, or major rearrangements. DNA viruses usually show greater genome stability than RNA viruses. However, recent genome-wide molecular evolution and experimental studies have shown that DNA viruses can exhibit rapid sequence changes that are often found in loci involved in dynamic host–virus interactions. In fact, DNA viruses are capable of promoting genome instability specifically at certain genes, thus boosting diversity wherein needed. We review some of the molecular mechanisms underlying genomic instability in prokaryotic and eukaryotic …
Tracking evolutionary trends towards increasing complexity: a case study in Cyanobacteria
2020
AbstractProgressive evolution, the tendency towards increasing complexity, is a controversial issue in Biology, whose resolution requires a proper measurement of complexity. Genomes are the best entities to address this challenge, as they record the history and information gaining of organisms in their ongoing biotic and environmental interactions. Using six metrics of genome complexity, none of which is primarily associated to biological function, we measure genome complexity in 91 genomes from the phylum Cyanobacteria. Several phylogenetic analyses reveal the existence of progressive evolution towards higher genome complexity: 1) all the metrics detect strong phylogenetic signals; 2) ridg…
From molecular genetics to phylodynamics: evolutionary relevance of mutation rates across viruses.
2012
Although evolution is a multifactorial process, theory posits that the speed of molecular evolution should be directly determined by the rate at which spontaneous mutations appear. To what extent these two biochemical and population-scale processes are related in nature, however, is largely unknown. Viruses are an ideal system for addressing this question because their evolution is fast enough to be observed in real time, and experimentally-determined mutation rates are abundant. This article provides statistically supported evidence that the mutation rate determines molecular evolution across all types of viruses. Properties of the viral genome such as its size and chemical composition are…
Reconstruction of the evolutionary history of Saccharomyces cerevisiae x S. kudriavzevii hybrids based on multilocus sequence analysis.
2012
In recent years, interspecific hybridization and introgression are increasingly recognized as significant events in the evolution of Saccharomyces yeasts. These mechanisms have probably been involved in the origin of novel yeast genotypes and phenotypes, which in due course were to colonize and predominate in the new fermentative environments created by human manipulation. The particular conditions in which hybrids arose are still unknown, as well as the number of possible hybridization events that generated the whole set of natural hybrids described in the literature during recent years. In this study, we could infer at least six different hybridization events that originated a set of 26 S…