Inferring genome trees by using a filter to eliminate phylogenetically discordant sequences and a distance matrix based on mean normalized BLASTP scores. | LitMetric
Darwin's paradigm holds that the diversity of present-day organisms has arisen via a process of genetic descent with modification, as on a bifurcating tree. Evidence is accumulating that genes are sometimes transferred not along lineages but rather across lineages. To the extent that this is so, Darwin's paradigm can apply only imperfectly to genomes, potentially complicating or perhaps undermining attempts to reconstruct historical relationships among genomes (i.e., a genome tree). Whether most genes in a genome have arisen via treelike (vertical) descent or by lateral transfer across lineages can be tested if enough complete genome sequences are used. We define a phylogenetically discordant sequence (PDS) as an open reading frame (ORF) that exhibits patterns of similarity relationships statistically distinguishable from those of most other ORFs in the same genome. PDSs represent between 6.0 and 16.8% (mean, 10.8%) of the analyzable ORFs in the genomes of 28 bacteria, eight archaea, and one eukaryote (Saccharomyces cerevisiae). In this study we developed and assessed a distance-based approach, based on mean pairwise sequence similarity, for generating genome trees. Exclusion of PDSs improved bootstrap support for basal nodes but altered few topological features, indicating that there is little systematic bias among PDSs. Many but not all features of the genome tree from which PDSs were excluded are consistent with the 16S rRNA tree.
Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017, China.
Background: Vernicia montana and V. fordii are economically important woody oil species in the Euphorbiaceae that have great industrial oil and ornamental greening properties, however, the wild resources of Vernicia trees have been reduced because of their habitat destruction. Considering the diverse economic and ecological importance of Vernicia species, it is important to collect more molecular data to determine the genetic differences between V.
The Malvaceae family, comprising 9 subfamilies and 4,225 species, includes economically significant taxa, such as Ceiba pentandra, Gossypium ekmanianum, Gossypium stephensii, Kokia drynarioides, Talipariti hamabo, and Durio zibethinus. Chloroplast (cp) genome research is crucial for elucidating the evolutionary divergence and species identification within this family. In this study, we assembled and annotated cp genomes of six Malvaceae species, conducting comprehensive comparative genomic and phylogenomic analyses.
State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
Background: Eucalyptus grandis, which was first comprehensively and systematically introduced to China in the 1980s, is one of the most important fast-growing tree species in the forestry industry. However, to date, no core collection has been selected from the germplasm resources of E. grandis based on growth and genetic relationship analysis.
Discovery of novel protein biomarkers for clinical applications is an active research field across a manifold of diseases. Despite some successes and progress, the biomarker development pipeline still frequently ends in failure. Biomarker candidates that are discovered by appropriate technologies such as unbiased mass spectrometry cannot be validated or translated to immunoassays in many cases.
Insects, especially forest pests, are frequently characterized by eruptive dynamics. These types of species can stay at low, endemic population densities for extended periods of time before erupting in large-scale outbreaks. We here present a mechanistic model of these dynamics for mountain pine beetle.
