Project description:The red sea urchin, Mesocentrotus franciscanus, is one the earth’s longest-lived animals, reported to live more than 100 years with indeterminate growth, life-long reproduction and no increase in mortality rate with age. To explore the idea that transcriptional stability is a key determinant of longevity and negligible senescence, age-related gene expression was examined in three tissues of the red sea urchin (Aristotle’s lantern muscle, esophagus and radial nerve cord). Genome-wide transcriptional profiling using RNA-Seq revealed remarkable stability in muscle and esophagus with very few age-related changes in gene expression. In contrast, expression of more than 900 genes was significantly altered with age in radial nerve cord including genes involved in nerve function, signaling, metabolism, cytoskeleton, transcriptional regulation and chromatin modification. Notably, there was an upregulation in expression of genes involved in synaptogenesis and axonogenesis suggesting enhanced nervous system activity with age. Among the signaling pathways affected by age, there was a downregulation in expression of key components of the mTOR signaling pathway and an upregulation of negative regulators of this pathway. This was accompanied by a reduction in expression of genes involved in protein synthesis and mitochondrial function and an increase in expression of genes that promote autophagy. Downregulation of the mTOR pathway together with the other observed changes reveals a unique age-related gene expression profile in the red sea urchin nervous system that may contribute to mitigation of the detrimental effects of aging in this long-lived animal.
Project description:The sea urchin S. purpuratus is a model organism for study of the genomic control circuitry underlying embryonic development. We examined the complete repertoire of genes expressed in the S. purpuratus embryo, up to late gastrula stage, by means of high-resolution custom tiling arrays covering the whole genome. We detected complete spliced structures even for genes known to be expressed at low leveles in only a few cells. At least 11,000 to 12,000 genes are used in embryogenesis. These include most of the genes encoding transcription factors and signaling proteins, as well as some classes of general cytoskeletal and metabolic proteins, but only a minor fraction of genes encoding immune functions and sensory receptors. Thousands of small asymmetric transcripts of unknown function were also detected in intergenic regions throughout the genome. The tiling array data were used to correct and authenticate several thousand gene models during the genome annotation process. Keywords: high-resolution tiling array, sea urchin, embryo Keywords: other
Project description:Seawater exposure to the gram negative marine bacterium Vibrio diazotrophicus induces a robust cellular response in sea urchin larvae that includes the migration of pigment cells to the gut epithelium, changes in cell behavior and altered gut morphology (Ho et al., 2016; PMID 27192936). To investigate the transcriptional underpinnings of this response, whole transcriptome sequencing was performed on mRNA isolated from larval samples collected at 0, 6, 12 and 24 hr of exposure to V. diazotrophicus. The morphological simplicity of the sea urchin larva provides a systems-level model for identifying biologically relevant transcriptional state changes in response to dysbiosis in the gut lumen.
Project description:In order to validate of CNV detection from low-coverage whole-genome sequencing in the blood samples from recurrent miscarriage couples, we employed a customized array Comparative Genomics Hybridization (aCGH, Agilent) approach as chromosomal microarray analysis (CMA) in present study for a cohort of 78 DNA samples from blood. CMA results were compared with low-coverage whole-genome sequencing detection results. 100% consistency was obtained in pathogenic or likely pathogenic CNVs detection.
Project description:We identified cis-regulatory elements based on their dynamic chromatin accessibility during the gastrula-larva stages of sea urchin and sea star and studied their evolution in these echinoderm species
Project description:Low coverage whole-genome sequencing have been performed on uterine leiomyosarcoma to uncovered novel potential driver genes and recurrently affected pathways.
Project description:Purpose: The Tbrain transcription factor has demonstrated an evolved preference for low-affinity, secondary site binding motifs between the sea star and sea urchin orthologs. We sought to identify targets of sea urchin and sea star orthologs of Tbr. Because less is known about the function of Tbr during sea star development, we used RNA-seq in conjuction with ChIP-seq studies (GEO:xxxx) to determine the targets of sea star Tbr in early development. Methods: Sea star (Patiria miniata) embryos were injected with translation-blocking morpholino antisense oligonucleotides to knock-down PmTbr expression, as described previously. Control morpholinos were injected into sibling embryos. Embryos were allowed to develop until hatching (30-36 hpf) at which point injected embryos were collected and RNA was extracted. RNA-seq libraries were prepared, sequenced, and analyzed using standard protocols. Results: There are 2,562 genes that are significantly differentially expressed relative to control morpholino inected embryos (FDR < 0.05). There are roughly equivalent numbers of genes down-regulated (1,041) and up-regulated (1,521) by Pm-tbr knockdown, suggesting that PmTbr may act as both a transcriptional activator and repressor. 1,165 differentially expressed genes are located within 75 kb of a PmTbr binding site determined using ChIP-seq, and this set is used as a basis for comparison between sea star and sea urchin binding sites. Conclusions: 1,165 targets of the PmTbr transcription factor were identified based on differential expression following knockdown and the presence of transcription factor binding sites proximal to differentially expressed genes. There are an equal number of up- and down-regulated targets, suggesting Tbr may function as a transcriptional activator and repressor, depending on context and target gene. There was no clear association of motif utilization with either the direction of differential expression or ontological category of the target gene. There are only a small fraction of target genes (approximately 10%) that are in common between the sea star and sea urchin sets.
Project description:Whole-genome DNA libraries were prepared from a population of just under 100 Col/Ler F1 backcrossed to Col. Low-coverage whole-genome sequencing was used to map meiotic crossovers in this population following the protocol described in Rowan et al., 2015, doi: 10.1534/g3.114.016501.
Project description:Low coverage whole genome sequencing (lc-WGS) from inducible Tet TKO (Tet iTKO) and control (Ctrl) mouse ESCs (mESC), as well as for germline Dnmt TKO mESCs. mESCs were sorted to isolate the Live/Dead dye and Thy1.2 negative CD326+GFP+ population representing the mESCs populations responsive to the tamoxifen treatment. The cells were resuspended in FACS buffer and filtered with a 70 µM filter before sorting. These bulk-population samples were analyzed by using low coverage Whole Genome Sequencing (lc-WGS).