Project description:Differences between species promote stable coexistence in a resource-limited environment. These differences can result from interspecies competition leading to character shifts, a process referred to as character displacement. While character displacement is often interpreted as a consequence of genetically fixed trait differences between species, it can also be mediated by phenotypic plasticity in response to the presence of another species. Here, we test whether phenotypic plasticity leads to a shift in proteome allocation during co-occurrence of two bacterial species from the abundant, leaf-colonizing families Sphingomonadaceae and Rhizobiaceae in their natural habitat. Upon mono-colonizing of the phyllosphere, both species exhibit specific and shared protein functions indicating a niche overlap. During co-colonization, quantitative differences in the protein repertoire of both bacterial populations occur as a result of bacterial coexistence in planta. Specifically, the Sphingomonas strain produces enzymes for the metabolization of xylan, while the Rhizobium strain reprograms its metabolism to beta-oxidation of fatty acids fueled via the glyoxylate cycle and adapts its biotin acquisition. We demonstrate the conditional relevance of cross-species facilitation by mutagenesis leading to loss of fitness in competition in planta. Our results show that dynamic character displacement and niche facilitation mediated by phenotypic plasticity can contribute to species coexistence.
Project description:Morphological characters are the result of developmental gene expression. Hence the identity of a character is ultimately grounded in the gene regulatory network directing development and thus whole genome gene expression data can provide evidence about character identity. Here we use transcriptomic data to address one of the most enduring paradoxes in evolutionary biology, the identity of the avian wing digits. Deep Sequencing of mRNA from embryonic chicken digits is performed and the gene expression profiles are analyzed.
Project description:Morphological characters are the result of developmental gene expression. Hence the identity of a character is ultimately grounded in the gene regulatory network directing development and thus whole genome gene expression data can provide evidence about character identity. Here we use transcriptomic data to address one of the most enduring paradoxes in evolutionary biology, the identity of the avian wing digits. Deep Sequencing of mRNA from embryonic chicken digits is performed and the gene expression profiles are analyzed. Analysis of mRNA-seq data from 16 samples of chicken digits covering two embryonic stages.
Project description:Recent single-cell studies have revealed that yeast stress response involves multiple transcription factors that are temporally activated in pulses. However, it remains largely unclear whether and how these dynamic transcription factors temporally interact to regulate stress survival. Here we show that budding yeast cells can exploit the temporal relationship between paralogous general stress regulators, Msn2 and Msn4, during stress response. We found that individual pulses of Msn2 and Msn4 are largely redundant, and cells can enhance the expression of their shared target genes by increasing their temporal divergence. Thus, functional redundancy between these two paralogs is modulated in a dynamic manner to confer fitness advantages for yeast cells, which might feed back to promote the preservation of their functional redundancy. This evolutionary implication was supported by evidence from Msn2/Msn4 orthologs and analyses of other transcription factor paralogs. Together, we show a cell fate control mechanism through temporal redundancy modulation in yeast, which may represent an evolutionarily important strategy for maintaining functional redundancy between gene duplicates.
2021-03-06 | GSE161373 | GEO
Project description:Evolutionary Genomics of Gypsy Moth
Project description:Gastro-esophageal adenocarcinomas (GEAs) are aggressive cancers and multiple trials of targeted therapies recently failed to improve survival in these tumors. Intratumor heterogeneity (ITH) is suspected to contribute to poor outcomes. Here we investigate the degree of ITH in multiple primary and metastatic regions of gastric adenocarcinoma tumours. ITH increased significantly with lymph node metastasis formation and subclonal aberrations activating the Mitogen Activated Protein Kinase (MAPK)-pathway were significantly enriched in nodal metastases. This shows that selection pressures in the lymph node ecosystem differ from those in the primary tumor, leading to evolutionary convergence of distinct tumors when they spread to lymph nodes.
Project description:PFGRC has developed a cost effective alternative to complete genome sequencing in order to study the genetic differences between closely related species and/or strains. The comparative genomics approach combines Gene Discovery (GD) and Comparative Genomic Hybridization (CGH) techniques, resulting in the design and production of species microarrays that represent the diversity of a species beyond just the sequenced reference strain(s) used in the initial microarray design. These species arrays may then be used to interrogate hundreds of closely related strains in order to further unravel their evolutionary relationships. The Neissiria are among most deadly pathogens world-wide. The infections and outbreaks caused by this pathogens is quite frequent despite existing diagnostic network and therapeutic means. Therefore, developing reliable diagnostic tools and efficient (broad-spectrum) therapeutics for Neisseria meningitidis remain a public health priority for every country in world today. The comparative genomics study will provide the largest hitherto genomic data sets regarding this pathogen.These large data sets will enable us as well as other members of scientific community to conduct comprehensive data mining in the form of gene association studies with statistical power and significance.