Inferring patterns of recombination and divergence with ancient and modern treponemal genomes
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ABSTRACT:
PROVIDER: PRJEB57584 | ENA |
REPOSITORIES: ENA
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Project description:In the social amoebae (Dictyostelia) quorum sensing system mediates aggregation of single cells into multicellular aggregates by chemotactic movement towards gradients of diffusible molecules known as acrasins. The acrasin of P. violaceum is the unusual dipeptide N-propionyl-gamma-L-glutamyl-L-ornithine-delta-lactam-ethylester, known as glorin. Phylogenetic analysis has indicated that P. violaceum is more related to the most derived group 4 dictyostelids than to the ancient group 2 polysphondylids such as P. pallidum. Nevertheless it has been reported that P. pallidum cells respond to glorin in chemotaxis assays. This has led to the assumption that glorin-based communication may be the most ancient form of intercellular communication that Dictyostelia invented to organize early steps of multicellular development. In this study we show that glorin mediates rapid changes in gene expression at the transition from vegetative growth to aggregation, apparently without pronounced cross-talk with the cyclic AMP-based communication system that coordinates post-aggregation events in this species. We describe glorin-mediated changes in gene expression in the social amoeba Polysphondylium pallidum at the transition from unicellular growth to multicellular development. Comparison of gene expression in growing cells versus cells starving for 2 or 3 hours in the presence or absence of glorin.
2010-10-29 | E-GEOD-24911 | biostudies-arrayexpress
Project description:In the social amoebae (Dictyostelia) quorum sensing system mediates aggregation of single cells into multicellular aggregates by chemotactic movement towards gradients of diffusible molecules known as acrasins. The acrasin of P. violaceum is the unusual dipeptide N-propionyl-gamma-L-glutamyl-L-ornithine-delta-lactam-ethylester, known as glorin. Phylogenetic analysis has indicated that P. violaceum is more related to the most derived group 4 dictyostelids than to the ancient group 2 polysphondylids such as P. pallidum. Nevertheless it has been reported that P. pallidum cells respond to glorin in chemotaxis assays. This has led to the assumption that glorin-based communication may be the most ancient form of intercellular communication that Dictyostelia invented to organize early steps of multicellular development. In this study we show that glorin mediates rapid changes in gene expression at the transition from vegetative growth to aggregation, apparently without pronounced cross-talk with the cyclic AMP-based communication system that coordinates post-aggregation events in this species. We describe glorin-mediated changes in gene expression in the social amoeba Polysphondylium pallidum at the transition from unicellular growth to multicellular development.
2010-10-29 | GSE24911 | GEO
Project description:Inferring genome-wide genealogies from modern and ancient genomes.
| PRJEB43093 | ENA
Project description:Southern African ancient genomes estimate modern human divergence to 350,000-260,000 years ago
| PRJEB22660 | ENA
Project description:Ancient Bacterial Genomes Reveal a High Diversity of Treponema pallidum Strains in Early Modern Europe
| PRJEB35855 | ENA
Project description:Genome-wide premortem DNA methylation patterns can be computationally reconstructed from high-coverage DNA sequences of ancient samples. As DNA methylation is more conserved across species than across tissues, and as ancient DNA is typically extracted from bones and teeth, previous works utilizing ancient DNA methylation maps focused on studying evolutionary changes in the skeletal system. Here, we suggest that DNA methylation patterns in one tissue may, under certain conditions, be informative on DNA methylation patterns in other tissues of the same individual. Using the fact that tissue- specific DNA methylation builds up during embryonic development, we identified the conditions that allow for such cross-tissue inference and devised an algorithm that carries it out. We trained the algorithm on methylation data from extant species and reached high precisions of up to 0.92 for validation data sets. We then used the algorithm on archaic humans, and identified more than 1,850 positions for which we were able to observe differential DNA methylation in prefrontal cortex neurons. These positions are linked to hundreds of genes, many of which are involved in neural functions such as structural and developmental processes. Six positions are located in the NBPF gene family, which likely played a role in human brain evolution. The algorithm we present here allows for the examination of epigenetic changes in tissues and cell types that are absent from the paleontological record, and therefore provides new ways to study the evolutionary impacts of epigenetic changes.
2025-01-22 | GSE276666 | GEO
Project description:Alignment of publicly available ancient genomes to hg38
| PRJEB64654 | ENA
Project description:The number of sequenced species is increasing at a staggering rate, calling for new approaches for incorporating evolutionary information in the study of biological mechanisms. Evolutionary conservation is widely used for assigning a function to new proteins and for predicting functional coding or non-coding sequences. Here, we argue for a complementary approach that focuses on the divergence of regulatory programs. Regulatory mechanisms can be learned from patterns of evolutionary divergence in regulatory properties such as gene expression, transcription factor binding or nucleosome positioning. We review examples of this concept using yeast as a model system, and highlight a hybrid-based approach that is highly instrumental in this analysis.
| S-EPMC3202799 | biostudies-other
Project description:The sequencing of modern and ancient genomes from around the world has revolutionized our understanding of human history and evolution. However, the problem of how best to characterize ancestral relationships from the totality of human genomic variation remains unsolved. Here, we address this challenge with nonparametric methods that enable us to infer a unified genealogy of modern and ancient humans. This compact representation of multiple datasets explores the challenges of missing and erroneous data and uses ancient samples to constrain and date relationships. We demonstrate the power of the method to recover relationships between individuals and populations as well as to identify descendants of ancient samples. Finally, we introduce a simple nonparametric estimator of the geographical location of ancestors that recapitulates key events in human history.
| S-EPMC10027547 | biostudies-literature