Project description:Whole-Genome Duplication and Acceleration of Molecular Evolution are Associated with the Early Diversification of Cornus L. (Cornaceae): Insights from De Novo Assembled Transcriptome Sequences
Project description:The evolution of gene body methylation (gbM) and the underlying mechanism is poorly understood. By pairing the largest collection of CHROMOMETHYLTRANSFERASE (CMT) sequences (773) and methylomes (72) across land plants and green algae we provide novel insights into the evolution of gbM and its underlying mechanism. The angiosperm- and eudicot-specific whole genome duplication events gave rise to what are now referred to as CMT1, 2 and 3 lineages. CMTε, which includes the eudicot-specific CMT1 and 3, and orthologous angiosperm clades, is essential for the perpetuation of gbM in angiosperms, implying that gbM evolved at least 236 MYA. Independent losses of CMT1, 2 and 3 in eudicots, and CMT2 and CMTmonocot+magnoliid in monocots suggests overlapping or fluid functional evolution. The resulting gene family phylogeny of CMT transcripts from the most diverse sampling of plants to date redefines our understanding of CMT evolution and its evolutionary consequences on DNA methylation.
Project description:Chromosome-level genome assembly of Bupleuri radix provides insights into the evolution of its genome and saikosaponin biosynthesis
Project description:The evolution and diversification of proteins capable of remodelling domains has been critical for transcriptional reprogramming during cell fate determination in multicellular eukaryotes. Chromatin remodelling proteins of the CHD3 family have been shown to have important and antagonistic impacts on seed development in the model plant, Arabidopsis thaliana, yet the basis of this functional divergence remains unknown. In this study, we demonstrate that genes encoding the CHD3 proteins PICKLE (PKL) and PICKLE-RELATED 2 (PKR2) originated from a duplication event during the diversification of crown Brassicaceae, and that these homologues have undergone distinct evolutionary trajectories since this duplication, with PKR2 fast-evolving under positive selection, while PKL is evolving under purifying selection. We find that the rapid evolution of PKR2 under positive selection reduces the encoded protein’s intrinsic disorder, possibly suggesting a tertiary structure configuration which differs from that of PKL. Our whole genome transcriptome analysis of gene expression in seeds of pkr2 and pkl mutants reveals that they act antagonistically on the expression of specific sets of genes, providing a basis for their differing roles in seed development. Our results provide insights on gene duplication and neofunctionalization can lead to differing and antagonistic selective pressures on transcriptomes during plant reproduction, as well as on the evolutionary diversification of the CHD3 family within seed plants.
Project description:The Crabtree phenotype defines whether a yeast can perform simultaneous respiration and fermentation under aerobic conditions at high growth rates, a phenomenon that resembles the Warburg effect in cancer cells. Whole genome duplication, global promoter rewiring and loss of respiratory complex I are the main molecular events that contributed to the evolution of Crabtree effect. Here we show that overexpression of a single Gal4-like transcription factor is sufficient to convert Crabtree-negative Komagataella phaffii (Pichia pastoris) into a Crabtree positive yeast. We report the transcriptome profile (RNASeq) of the Δgal4-like and Gal4-like overexpression K. phaffii strains. Upregulation of the glycolytic genes and a significant increase in glucose uptake rate due to the overexpression of the Gal4-like transcription factor caused an overflow metabolism, triggering both short-term and long-term Crabtree phenotypes. This indicates that a single mutation leading to overexpression of one gene may have been sufficient as a first molecular event towards respiro-fermentative metabolism in the course of yeast evolution.
Project description:Orphan genes are characteristic genomic features that have no detectable homology to genes in any other species and represent an important attribute of genome evolution as sources of novel genetic functions. Here, we identified 445 genes specific to Populus trichocarpa. Of these, we performed deeper reconstruction of 13 orphan genes to provide evidence of de novo gene evolution. Populus and its sister genera Salix are particularly well suited for the study of orphan gene evolution because of the Salicoid whole-genome duplication event (WGD) which resulted in highly syntenic sister chromosomal segments across the Salicaceae. We leveraged this genomic feature to reconstruct de novo gene evolution from inter-genera, inter-species, and intra-genomic perspectives by comparing the syntenic regions within the P. trichocarpa reference, then P. deltoides, and finally Salix purpurea. Furthermore, we demonstrated that 86.5% of the putative orphan genes had evidence of transcription. Additionally, we also utilized the Populus genome-wide association mapping panel (GWAS), a collection of 1,084 undomesticated P. trichocarpa genotypes to further determine putative regulatory networks of orphan genes using expression quantitative trait loci (eQTL) mapping. Collectively, we provide novel insights into the processes of de novo gene evolution in the context of a long-lived eukaryote.
Project description:De novo sequencing, characterization, and comparison of inflorescence transcriptomes of Cornus canadensis and C. florida (Cornaceae)
Project description:This set of arrays contains all microarray experiments done involving comparisons among C. elegans natural isolates and mutation-accumulation lines. Abstract: The evolutionary importance of gene-expression divergence is unclear: some studies suggest that it is an important mechanism for evolution by natural selection, whereas others claim that most between-species regulatory changes are neutral or nearly neutral. We examined global transcriptional divergence patterns in a set of Caenorhabditis elegans mutation-accumulation lines and natural isolate lines to provide insights into the evolutionary importance of transcriptional variation and to discriminate between the forces of mutation and natural selection in shaping the evolution of gene expression. We detected the effects of selection on transcriptional divergence patterns and characterized them with respect to coexpressed gene sets, chromosomal clustering of expression changes and functional gene categories. We directly compared observed transcriptional variation patterns in the mutation-accumulation and natural isolate lines to a neutral model of transcriptome evolution to show that strong stabilizing selection dominates the evolution of transcriptional change for thousands of C. elegans expressed sequences. An all pairs experiment design type is where all labeled extracts are compared to every other labeled extract. Computed