Project description:We have determined methylation state differences in the epigenomes of neutrophils purified from human and chimpanzee. We used deep sequencing of ends generated by digestion with a methylation-sensitive restriction enzyme, followed by analysis with the MetMap computational pipeline to infer methylation states from the sequencing data. Using the orangutan as an outgroup, analysis of DNA sequence substitutions in CG-dense regions that are either methylated or unmethylated in all three species indicates that methylation states in the neutrophil reflect methylation states in the germline. Differences in methylation states were not correlated with differences in the local genomic sequences, indicating that they can be determined independently of local DNA sequence. Methylation differences were not distributed randomly among the individuals we analyzed, but recapitulated the known phylogenetic relationships of the three species in a pattern consistent with their stable inheritance. This data provide the first comprehensive dataset indicating that epigenetic states are maintained as independent characters that are predictably transmitted within species. Heritable epigenetic differences such as those we have identified could readily have functional and adaptive consequences, and contribute to the phenotypic divergence of human and chimpanzee. Comparison of methylation states in a single, uncultered cell type from human and chimpanzee
Project description:We have determined methylation state differences in the epigenomes of neutrophils purified from human and chimpanzee. We used deep sequencing of ends generated by digestion with a methylation-sensitive restriction enzyme, followed by analysis with the MetMap computational pipeline to infer methylation states from the sequencing data. Using the orangutan as an outgroup, analysis of DNA sequence substitutions in CG-dense regions that are either methylated or unmethylated in all three species indicates that methylation states in the neutrophil reflect methylation states in the germline. Differences in methylation states were not correlated with differences in the local genomic sequences, indicating that they can be determined independently of local DNA sequence. Methylation differences were not distributed randomly among the individuals we analyzed, but recapitulated the known phylogenetic relationships of the three species in a pattern consistent with their stable inheritance. This data provide the first comprehensive dataset indicating that epigenetic states are maintained as independent characters that are predictably transmitted within species. Heritable epigenetic differences such as those we have identified could readily have functional and adaptive consequences, and contribute to the phenotypic divergence of human and chimpanzee.
2011-09-09 | GSE22376 | GEO
Project description:Transcriptomes to assess the phylogenetic relationships within Polynoidae (Annelida)
| PRJNA882866 | ENA
Project description:Genomes of two species within the order Lysobacterales
Project description:A phylogenetic analysis of seven different species (human, mouse, rat, worm, fly, yeast, and plant) utilizing all (541) basic helix-loop-helix (bHLH) genes identified, including expressed sequence tags (EST), was performed. A super-tree involving six clades and a structural categorization involving the entire coding sequence was established. A nomenclature was developed based on clade distribution to discuss the functional and ancestral relationships of all the genes. The position/location of specific genes on the phylogenetic tree in relation to known bHLH factors allows for predictions of the potential functions of uncharacterized bHLH factors, including EST's. A genomic analysis using microarrays for four different mouse cell types (i.e. Sertoli, Schwann, thymic, and muscle) was performed and considered all known bHLH family members on the microarray for comparison. Cell-specific groups of bHLH genes helped clarify those bHLH genes potentially involved in cell specific differentiation. This phylogenetic and genomic analysis of the bHLH gene family has revealed unique aspects of the evolution and functional relationships of the different genes in the bHLH gene family. PMID: 18557763 We used microarrays to determine bHLH expression in 20d rat Sertoli cells. RNA samples from two control groups (Sertoli cells cultured for 72 h) are compared to two treated groups (Sertoli cells cultured for 72 h with cAMP).
Project description:<p>Intratumoral genetic heterogeneity has been characterized across cancers by genome sequencing of bulk tumors, including chronic lymphocytic leukemia (CLL). In order to more accurately identify subclones, define phylogenetic relationships, and probe genotype-phenotype relationships, we developed methods for targeted mutation detection in DNA and RNA isolated from thousands of single cells from five CLL samples. By clearly resolving phylogenic relationships, we uncovered mutated LCP1 and WNK1 as novel CLL drivers, supported by functional evidence demonstrating their impact on CLL pathways. Integrative analysis of somatic mutations with transcriptional states prompts the idea that convergent evolution generates phenotypically similar cells in distinct genetic branches, thus creating a cohesive expression profile in each CLL sample despite the presence of genetic heterogeneity. Our study highlights the potential for single-cell RNA-based targeted analysis to sensitively determine transcriptional and mutational profiles of individual cancer cells leading to increased understanding of driving events in malignancy.</p> <p>Reprinted from Genome Research, with permission from Publisher.</p>
Project description:Ancient DNA (aDNA) sequencing has enabled reconstruction of speciation, migration, and admixture events for extinct taxa. Outside the permafrost, however, irreversible aDNA post-mortem degradation has so far limited aDNA recovery to the past ~0.5 million years (Ma). Contrarily, multiple analyses suggested the presence of protein residues in Cretaceous fossil remains. Similarly, tandem mass spectrometry (MS) allowed sequencing ~1.5 million year (Ma) old collagen type I (COL1), though with limited phylogenetic use. In the absence of molecular evidence, the speciation of several Early and Middle Pleistocene extinct species remain contentious. In this study, we address the phylogenetic relationships of the Eurasian Pleistocene Rhinocerotidae using a ~1.77 Ma old dental enamel proteome of a Stephanorhinus specimen from the Dmanisi archaeological site in Georgia (South Caucasus). Molecular phylogenetic analyses place the Dmanisi Stephanorhinus as a sister group to the woolly (Coelodonta antiquitatis) and Merck’s rhinoceros (S. kirchbergensis) clade. We show that Coelodonta evolved from an early Stephanorhinus lineage and that the latter includes at least two distinct evolutionary lines. As such, the genus Stephanorhinus is currently paraphyletic and requires systematic revision. We demonstrate that Early Pleistocene dental enamel proteome sequencing overcomes the limits of ancient collagen- and aDNA-based phylogenetic inference. It also provides additional information about the sex and taxonomic assignment of the specimens analysed. Dental enamel, the hardest tissue in vertebrates, is highly abundant in the fossil record. Our findings reveal that palaeoproteomic investigation of this material can push biomolecular investigation further back into the Early Pleistocene.