Project description:The evolution of gene body methylation (gbM) and the underlying mechanism is poorly understood. By pairing the largest collection of CHROMOMETHYLTRANSFERASE (CMT) sequences (773) and methylomes (72) across land plants and green algae we provide novel insights into the evolution of gbM and its underlying mechanism. The angiosperm- and eudicot-specific whole genome duplication events gave rise to what are now referred to as CMT1, 2 and 3 lineages. CMTε, which includes the eudicot-specific CMT1 and 3, and orthologous angiosperm clades, is essential for the perpetuation of gbM in angiosperms, implying that gbM evolved at least 236 MYA. Independent losses of CMT1, 2 and 3 in eudicots, and CMT2 and CMTmonocot+magnoliid in monocots suggests overlapping or fluid functional evolution. The resulting gene family phylogeny of CMT transcripts from the most diverse sampling of plants to date redefines our understanding of CMT evolution and its evolutionary consequences on DNA methylation. Overall design: MethylC-Seq collected from leaves of a diverse collection of land plants. The assembled transcriptomes used in this study were not publicly available at the time of submission since they are part of the on-going 1KP initiative (www.onekp.com). They will be made available upon release of the 1KP capstone paper.
Project description:We found many binding sites for ArcA under glucose fermentative anaerobic growth conditions. Descirbed in the manuscript "The response regulator ArcA uses a diverse binding site architechture to globally regulate carbon oxidation in E. coli" Examination of occupancy of ArcA under anaerobic growth conditions.
Project description:How does environmental change drive phenotypic evolution? We addressed this question using Daphnia genotypes separated by ~1600-years of evolution in a Minnesota lake using methods in resurrection ecology (i.e., reviving dormant eggs from sediments) and found substantial genetic and physiological differentiation. These shifts are highly correlated with anthropogenic environmental change, specifically phosphorus (P)-driven eutrophication. Here, we explore transcriptomic changes that may underlie the observed shifts in P use physiology (see poster by Fricsh et al for a detailed explanation). We compared the transcriptomes of two ancient and two contemporary genotypes in ancient (i.e., low P; LP) and contemporary (i.e., high P; HP) conditions using an 11000-gene microarray. Ancient and contemporary genotypes differed in the number of differentially expressed genes in the HP (mean ± SD; 645 ± 112.95) and LP (1071 ± 211.63) treatments. These results indicate considerable transcriptomic variation between ancient and contemporary genotypes in both dietary treatments, with stressful (LP) conditions invoking differential expression of more genes (t= -2.51; P= 0.04). Moreover, ancient and contemporary genotypes exhibited markedly different transcriptomic responses to dietary treatments. Contemporary genotypes upregulated 84.5 ± 28.99 while ancient genotypes upregulated 413.5 ± 26.16 genes (t= 164.5; P= 0.003). Similarly, ancient (127.5 ± 101.1) and contemporary (316 ± 98.99) genotypes differed significantly in the number of genes downregulated between the HP and LP treatments (t= 125.66; P= 0.005). These results indicate substantial regulatory shifts may underlie the striking physiological differences observed. Further analyses of gene families that were differentially expressed (DE) between ancient and contemporary genotypes revealed several gene families already known to be important in mitigating stoichiometric imbalances driven by P availability. Agglomerative hierarchical cluster analyses of DE loci between ancient and contemporary genotypes indicating age-based clustering will be presented. Together, our theoretical framework based on elemental supply, and unique model system enabled a millennial-scale exploration of the environmental contribution to phenotypic evolution. Overall design: 2 ~700-yr-old clones (SC1X & SC3X), 2 ~10-yr-old clones (SC4B & SC15A), two dietary treatments (C:P~120 and C:P~800) of Scenedesmus algae. Exposed for 3 days.
Project description:The purpose of this study is to (1) compare a technically improved assay with an existing assay used to measure serum anti-GM-CSF antibodies in stored serum samples previously obtained from patients diagnosed with either primary, secondary, congenital or idiopathic pulmonary alveolar proteinosis (PAP), other chronic diseases or disease-free, healthy individuals; (2) determine the prevalence and levels of anti-GM-CSF autoantibodies and (3) define the breadth of the autoimmune antibody responses in primary PAP patients from the United States, Japan, Australia, and Europe using previously collected serum samples; and (4) using a chart review approach, compare the clinical, radiologic and laboratory features of primary PAP patients to determine if differences exist among patients in these globally geographically distributed regions.
Project description:Understanding the extent of genomic transcription and its functional relevance is a central goal in genomics research. However, detailed genome‐wide investigations of transcriptome complexities in major mammalian organs and their underlying cellular sources, transcriptional mechanisms, and functional relevance have been scarce. Here we first show, using extensive RNA‐seq data, that transcription of both functional and nonfunctional genomic elements is substantially more widespread in the testis than in other organs across representative mammals. By scrutinizing the transcriptomes of all main testicular cell types in the mouse, we then reveal that meiotic spermatocytes and especially post‐meiotic round spermatids have remarkably diverse transcriptomes, which explains the high transcriptome complexity of the testis as a whole. The widespread transcriptional activity in spermatocytes and spermatids encompasses protein‐coding genes and long noncoding RNA genes but also poorly conserved intergenic sequences, suggesting that much of it is not of immediate functional relevance. Rather, our analyses of genome‐wide epigenetic data show that this prevalent transcription, which apparently promoted the birth of new genes during evolution, results from a highly permissive chromatin state during and after meiosis that may ultimately facilitate the replacement of histones by protamines during late spermatogenesis. To study the cellular source and mechanisms of high transcriptome complexity in the mammalian testis, we generated strand-specific deep coverage RNA‐Seq data for purified sertoli cells, spermatogonia, spermatocytes, spermatids and spermatozoa as well as for brain, liver and the whole testis from the mouse. We prepared 8 sequencing libraries for the polyadenylated RNA fraction of each sample and sequenced each library in 3 lanes of the Illumina Genome Analyser IIx platform, yielding a total of >60 millions strand-specific reads of 76 base pairs per sample. In addition, we generated ChIP-Seq data for the H3K4me2 modification as well as RRBS data for brain, liver, testis, spermatocytes and spermatids. RNA-seq, ChIP-seq and RRBS data were generated from the same individual or pool of individuals, in the case of purified cells. ChIP-Seq data for the H3K4me2 modification as well as RRBS data for brain, liver, testis, spermatocytes and spermatids
Project description:Foxp3+ regulatory T (TR) cells are phenotypically and functionally diverse, and broadly distributed in lymphoid and non-lymphoid tissues. However, the pathways guiding the differentiation of tissue-resident TR populations have not been well defined. By regulating E-protein function, Id3 controls the differentiation of CD8+ effector T cells and is essential for TR maintenance and function. We show that dynamic expression of Id3 helps define three distinct mouse TR populations, Id3+CD62LhiCD44lo central (c)TR, Id3+CD62LloCD44hi effector (e)TR and Id3- eTR. Adoptive transfer experiments and transcriptome analyses support a stepwise model of differentiation from Id3+ cTR to Id3+ eTR to Id3- eTR. Furthermore, Id3- eTR have high expression of functional inhibitory markers and a transcriptional signature of tissue-resident TR. Accordingly, Id3- eTR are highly enriched in non-lymphoid organs, but virtually absent from blood and lymph. Thus, we propose that tissue-resident TR develop in a multi-step process associated with Id3 downregulation. Overall design: Biological triplicates from three different populations in lymph node and spleen.
Project description:Bilaterian animals differ from other metazoans in their apparent bilateral symmetry and the development of a third germ layer. Both might have facilitated the evolution of the diverse and complex bilaterian body plans. The first cnidarian genome sequence revealed that despite their morphological simplicity, this sister group to all bilaterians shares an immense genomic complexity with vertebrates. This suggested that it might have been the complexity of gene regulation which increased during the evolution of bilaterians. We compared the gene regulatory landscape of cnidarians and bilaterians. To this end we generated the first genome-wide prediction of gene regulatory elements and profiled five epigenetic marks in a non-bilaterian animal, the cnidarian Nematostella vectensis. We found that the location of chromatin modifications relative to genes and distal enhancers is conserved among eumetazoans. Surprisingly, the genomic landscape of gene regulatory elements is highly similar between Nematostella and bilaterian model organisms. This suggests that complex regulation of developmental gene expression evolved in eumetazoans without a major increase in complexity in bilaterians. ChIP-seq of p300, RNA Pol2, and five histone modifications in Nematostella vectensis.
Project description:Recent studies have found that known functions of circRNAs include sequestration of microRNAs or proteins, modulation of transcription and interference with splicing, and even translation to produce poly-peptides. The zebrafish model is also demonstrably similar to humans in many studies. In order to explore the changes in circRNAs during embryonic development, further to research the mechanism of action of circRNAs in development-related diseases. Zebrafish embryos at blastula period, gastrula period, segmentation period, throat stage and incubation period were collected. Illumina deep sequencing technology and CIRI algorithm were used to detecting circRNAs. Totally we identified 1028 circRNAs (junction reads ≥ 5 and p < 0.05). Considering that circRNAs function is related to host genes, then bioinformatics analysis revealed these differentially expressed host genes are involved in NOTCH signaling pathways, cardiovascular system development, retinal ganglion cell axon guidance and so on. Moreover, circRNAs can participate in biological regulation through miRNA sponges function. TargetScan and miRanda were used to predict 73 miRNAs binding to circRNAs such as miR-19b, miR-124 and so on, some miRNAs play important roles in embryogenesis. The peak expression of circRNAs is distributed at different time points, suggesting that it may be involved in embryogenesis at different stages. Our study provides a foundation for understanding the dynamic regulation of circRNA transcriptomes during embryogenesis and identifies novel key circRNAs that might control embryonic development in zebrafish model. Overall design: circRNAs of five periods (blastula, gastrula, segmentation, throat and incubation) in zebrafish were detected by deep sequencing using Illumina HiSeq 2500.