Ontology highlight
ABSTRACT:
PROVIDER: PRJNA376572 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:In the seabed, chemical defences mediate inter- and intraspecific interactions and may determine organisms’ success, shaping the diversity and function of benthic communities. Sponges represent a prominent example of chemically-defended marine organisms with great ecological success. The ecological factors controlling the production of their defensive compounds and the evolutionary forces that select for these defences remain little understood. Each sponge species produces a specific and diverse chemical arsenal with fish-deterrent, antifouling and antimicrobial properties. However, some small animals (mesograzers), mainly sea slugs, have specialized in living and feeding on sponges. Feeding on chemically-defended organisms provides a strategy to avoid predators, albeit the poor nutritional value of sponges. In order to investigate the mechanisms that control sponge chemical defence, with particular focus on the response to specialist grazers, we investigated the interaction between the sponge Aplysina aerophoba and the sea slug Tylodina perversa. Here we performed controlled experiments and collected sponge samples at different time points (3h, 1d and 6d after treatment). To further elucidate if the sponge response is specific to grazing by T. perversa, we also included a treatment in which sponges were mechanically damaged with a scalpel. We compared gene expression between treatments based on RNA-Seq data.
2022-01-30 | E-MTAB-8601 | biostudies-arrayexpress
Project description:To study the evolutionary dynamics of regulatory DNA, we mapped >1.3 million deoxyribonuclease I–hypersensitive sites (DHSs) in 45 mouse cell and tissue types, and systematically compared these with human DHS maps from orthologous compartments. We found that the mouse and human genomes have undergone extensive cis-regulatory rewiring that combines branch-specific evolutionary innovation and loss with widespread repurposing of conserved DHSs to alternative cell fates, and that this process is mediated by turnover of transcription factor (TF) recognition elements. Despite pervasive evolutionary remodeling of the location and content of individual cis-regulatory regions, within orthologous mouse and human cell types the global fraction of regulatory DNA bases encoding recognition sites for each TF has been strictly conserved. Our findings provide new insights into the evolutionary forces shaping mammalian regulatory DNA landscapes.
2014-11-20 | GSE51336 | GEO
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
2006-01-31 | E-GEOD-4123 | biostudies-arrayexpress
Project description:The conservation and development of chicken has considerably affected human activities, but the admixture history of chicken breeds has so far been poorly demonstrated especially for Chinese indigenous breeds. Using genotypes from 580961 single nucleotide polymorphism markers scored in 1201 animals, we evaluate the genetic diversity (heterozygosity and proportion of polymorphic markers), Linkage disequilibrium (LD) decay, population structure (principal component analysis and neighbor-joining tree), genetic differentiation (FST and genetic distance) and migration events (Treemix and f-statistics) of eight domesticated chicken breeds. All population analytical methods reveal patterns of hybridization which occurred after divergence in Tibetan chicken. We argue that chicken migration and admixture followed by trade have been important forces in shaping modern Chinese chicken genomic variation. Moreover, isolation by distance may play critical role in the shaping genomic variation within Eurasia continent chicken breeds.
2019-10-07 | GSE127968 | GEO
Project description:Whole-chromatin profile (FAIRE-seq) in three Drosophila species (D. melanogaster, D. pseudoobscura and D. virilis) in eye-antennal imaginal discs at the stage of third instar wandering larvae. By the use of Ornstein-Uhlenbeck methods, we assess the evolutionary forces acting on regulatory elements (cis-level) on chromatin activity across Drosophila eye-antennal imaginal discs at the stage of third instar larvae.
2015-06-17 | E-GEOD-59706 | biostudies-arrayexpress
Project description:The lack of a comprehensive map of transcription start sites (TSS) across P. falciparum genome has hampered advances in decrypting the molecular mechanisms underlying regulation of gene expression in the malaria parasite. In eukaryotic model organisms, development of genome-wide approaches and next-generation sequencing technologies has contributed to a better understanding of the impact of local nucleotide composition on transcriptional regulation. Using such methods, we generated a single nucleotide-resolution map of transcription initiation events during P. falciparum intra-erythrocytic developmental cycle. Examination of transcription start site during the intra-erythorcytic development of the human parasite Plasmodium falciparum
2016-03-02 | E-GEOD-68982 | biostudies-arrayexpress
Project description:The lack of a comprehensive map of transcription start sites (TSS) across P. falciparum genome has hampered advances in decrypting the molecular mechanisms underlying regulation of gene expression in the malaria parasite. In eukaryotic model organisms, development of genome-wide approaches and next-generation sequencing technologies has contributed to a better understanding of the impact of local nucleotide composition on transcriptional regulation. Using such methods, we generated a single nucleotide-resolution map of transcription initiation events during P. falciparum intra-erythrocytic developmental cycle.
2016-03-02 | GSE68982 | GEO
Project description:Transcription initiation involves the recruitment of basal transcription factors to the core promoter. A variety of core promoter elements exists, however for most of these motifs the distribution across species is unknown. Here we report on the comparison of human and amphibian promoter sequences. We have used oligo-capping in combination with deep sequencing to determine transcription start sites in Xenopus tropicalis. To systematically predict regulatory elements we have developed a de novo motif finding pipeline using an ensemble of computational tools. A comprehensive comparison of human and amphibian promoter sequences revealed both similarities and differences in core promoter architecture. Some of the differences stem from a highly divergent nucleotide composition of Xenopus and human promoters. Whereas the distribution of some core promoter motifs is conserved independent of species-specific nucleotide bias, the frequency of another class of motifs correlates with the single nucleotide frequencies. This class includes the well-known TATA box and SP1 motifs, which are more abundant in Xenopus and human promoters, respectively. While these motifs are enriched above the local nucleotide background in both organisms, their frequency varies in step with this background. These differences are likely adaptive as these motifs can recruit TFIID to either CpG island or sharply initiating promoters. Our results highlight both conserved and diverged aspects of vertebrate transcription, most notably showing co-opted motif usage to recruit the transcriptional machinery to promoters with diverging nucleotide composition. This shows how sweeping changes in nucleotide composition are compatible with highly conserved mechanisms of transcription initiation. ChIP-seq profiles of TBP in Xenopus tropicalis stage 12 embryos and TSS-seq profiles of Xenopus oocytes and stage 12 embryos
2010-12-30 | E-GEOD-21482 | biostudies-arrayexpress
Project description:Sex chromosomes are characterized by a non-random content of genes with preferential expression in one sex. The mechanisms which are responsible for this phenomenon are, however, largely unresolved. To elucidate selective forces shaping the Z chromosome gene content in chicken, we analyzed microarray data from adult and embryonic gonads (the latter already available in GEO Series GSE8693).
2009-12-01 | GSE14013 | GEO
Project description:Transcription initiation involves the recruitment of basal transcription factors to the core promoter. A variety of core promoter elements exists, however for most of these motifs the distribution across species is unknown. Here we report on the comparison of human and amphibian promoter sequences. We have used oligo-capping in combination with deep sequencing to determine transcription start sites in Xenopus tropicalis. To systematically predict regulatory elements we have developed a de novo motif finding pipeline using an ensemble of computational tools. A comprehensive comparison of human and amphibian promoter sequences revealed both similarities and differences in core promoter architecture. Some of the differences stem from a highly divergent nucleotide composition of Xenopus and human promoters. Whereas the distribution of some core promoter motifs is conserved independent of species-specific nucleotide bias, the frequency of another class of motifs correlates with the single nucleotide frequencies. This class includes the well-known TATA box and SP1 motifs, which are more abundant in Xenopus and human promoters, respectively. While these motifs are enriched above the local nucleotide background in both organisms, their frequency varies in step with this background. These differences are likely adaptive as these motifs can recruit TFIID to either CpG island or sharply initiating promoters. Our results highlight both conserved and diverged aspects of vertebrate transcription, most notably showing co-opted motif usage to recruit the transcriptional machinery to promoters with diverging nucleotide composition. This shows how sweeping changes in nucleotide composition are compatible with highly conserved mechanisms of transcription initiation.
2010-12-30 | GSE21482 | GEO