Project description:We performed threefold evolution experiment with tobacco etch potyvirus isolate At17b (TEV-At17b) in five different ecotypes of Arabidopsis thaliana L. (Di-2, Ei-2, Ler-0, St-0, and Wt-1,), that are heterogeneous in their susceptibility to TEV-At17b infection. After the evolution phase, (i) we characterized the fitness and virulence of the evolved lineages across all host ecotypes, (ii) the molecular changes fixed in the viral genomes. Next, we analyzed the transcriptoma of the plants using Agilent Microarray tecnology (i)plants infected with local adapted viral lineage, (ii)plants infected with evolved virus vs. ancestal virus, (iii) virus evolved in new host and infecting its original host, (iv) transcriptoma of most specialized and most generalized viruses infecting all five ecotypes.
Project description:The metabolome of a cell is the integration point of an organism's environment, genetics, and gene expression pattern. The metabolic phenotype can be under selection and is known to contribute to adaption. However, the metabolome's inherent networked and convoluted nature makes relating mutations, metabolic changes, and effects on fitness challenging. To overcome this challenge, we use the Long Term Evolution Experiment (LTEE) as a model to understand how mutations can transduce themselves through a cellular network, eventually affecting metabolism and perhaps fitness. We used mass-spectropscopy to broadly survey the metabolomes of both ancestors and all 12 evolved lines and combined this with genomic and expression data to suggest how mutations that alter specific reaction pathways, such as the biosynthesis of nicotinamide adenine dinucleotide, might increase fitness in the system. Our work brings the field closer to a complete genotype-phenotype map for the LTEE and a better understanding of how mutations might affect fitness through the metabolome. We used mass-spectroscopy to profile metabolic changes in the Long Term Evolution Experiment and link these change to upstream changes in gene expression and mutations.
2022-12-01 | ST002431 | MetabolomicsWorkbench
Project description:Organelle genome diversity of carnivorous plants
Project description:Crassulacean acid metabolism (CAM) is a water-use efficient adaptation of photosynthesis that has evolved independently many times in diverse lineages of flowering plants. We hypothesize that convergent evolution of protein sequence and temporal gene expression underpins the independent emergences of CAM from C3 photosynthesis. To test this hypothesis, we generated a de novo genome assembly and genome-wide transcript expression data for Kalanchoe fedtschenkoi, an obligate CAM species within the core eudicots with a relatively small genome (~260 Mb). Our comparative analyses identified signatures of convergence in protein sequence and re-scheduling of diel transcript expression of genes involved in nocturnal CO2 fixation, stomatal movement, heat tolerance, circadian clock and carbohydrate metabolism in K. fedtschenkoi and other CAM species in comparison with non-CAM species. These findings provide new insights into molecular convergence and building blocks of CAM and will facilitate CAM-into-C3 photosynthesis engineering to enhance water-use efficiency in crops.
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:The cercozoan amoeba Paulinella chromatophora contains photosynthetic organelles - termed chromatophores - that evolved from a cyanobacterium independently from plastids in plants and algae. Despite the more recent origin of the chromatophore, it shows tight integration into the host cell. It imports hundreds of nucleus-encoded proteins, and diverse metabolites are exchanged across the two chromatophore envelope membranes. However, the limited set of chromatophore-encoded transporters appears insufficient for supporting metabolic connectivity or protein import. Furthermore, chromatophore-localized biosynthetic pathways as well as multiprotein complexes include proteins of dual genetic origin, suggesting coordination of gene expression levels between chromatophore and nucleus. These findings imply that similar to the situation in mitochondria and plastids, nuclear factors evolved that control metabolite exchange and gene expression in the chromatophore. Here we show by mass spectrometric analyses of enriched insoluble protein fractions that, unexpectedly, nucleus-encoded transporters are not inserted into the chromatophore inner envelope membrane. Thus, despite the apparent maintenance of its barrier function, canonical metabolite transporters are missing in this membrane. Instead we identified several expanded groups of short chromatophore-targeted orphan proteins. Members of one of these groups are characterized by a single transmembrane helix, and others contain amphipathic helices. We hypothesize that these proteins are involved in modulating membrane permeability. Furthermore, we identified an expanded family of chromatophore-targeted helical repeat proteins. These proteins show similar domain architectures as known organelle-targeted octotrico peptide repeat expression regulators in algae and plants suggesting their convergent evolution as nuclear regulators of gene expression levels in the chromatophore.
Project description:Chemostat evolution experiment C1 under glucose-limited condition at 30C. Gene Expression profiles of adaptive clones M1-M5 in evolved conditions compared with original parents. An all pairs experiment design type is where all labeled extracts are compared to every other labeled extract. Genotype: Evolved clones. The genotype is not necessarily complete. Keywords: all_pairs Gene Expression profiles of adaptive clones M1-M5 in evolved conditions compared with original parents
Project description:Diversification of histone variants is marked by the acquisition of distinct motifs and features through convergent evolution. H2A variants tend to be associated with defined domains of the genome. Specific features distinguish H2A variants in eukaryotes but whether evolution of these features predated the evolution of deposition mechanisms or vice-versa has remained unclear.In flowering plants, the variant H2A.W is tightly associated with heterochromatin. H2A.W evolved in land plants through acquisition of an extended C-terminal tail enriched with basic residues and a KSPK motif. Here, we used a synthetic approach in fission yeast, which lacks H2A.W and its dedicated deposition mechanism, to recapitulate the evolutionary steps that led to H2A.W and to assess the impact of the KSPK motif on heterochromatin composition and its properties. In conclusion, the acquisition of the KSPK motif in yeast promotes chromatin properties that are comparable to the properties and function of H2A.W in plant heterochromatin. Hence, the KSPK motif could have been selected before the evolution of direct heterochromatin deposition mechanisms. We propose that the acquisition of functional histone variant motifs can confer properties which affect only specific chromatin states, thereby driving the evolution of specific deposition mechanisms.