Inter-replicon gene flow contributes to transcriptional integration in the Sinorhizobium meliloti multipartite genome
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PROVIDER: PRJNA415644 | ENA |
REPOSITORIES: ENA
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Project description:Integration of newly acquired genes into existing regulatory networks is necessary for successful horizontal gene transfer (HGT). Ten percent of bacterial species contain at least two DNA replicons over 300 kilobases in size, with the secondary replicons derived predominately through HGT. The Sinorhizobium meliloti genome is split between a 3.7 Mb chromosome, a 1.7 Mb chromid (termed pSymB) consisting largely of genes acquired through ancient HGT, and a 1.4 Mb megaplasmid (termed pSymA) consisting primarily of recently acquired genes. Here, RNA-sequencing is used to examine the transcriptional consequences of massive, synthetic genome reduction produced through the removal of the megaplasmid and/or the chromid. Removal of the megaplasmid influenced the transcription of only six genes. In contrast, removal of the chromid influenced expression of ~ 8% of chromosomal genes and ~ 4% of megaplasmid genes. This was mediated in part by the loss of the ETR DNA region whose presence on pSymB is due to a translocation from the chromosome. No obvious functional bias among the up-regulated genes was detected, although genes with putative homologs on the chromid were enriched. Down-regulated genes were enriched in motility and sensory transduction pathways. Four transcripts were examined further, and in each case the transcriptional change could be traced to loss of specific pSymB regions. In particularly, a chromosomal transporter was induced due to deletion of bdhA likely mediated through 3-hydroxybutyrate accumulation. These data provide new insights into the evolution of the multipartite bacterial genome, and more generally into the integration of horizontally acquired genes into the transcriptome.
2018-02-03 | GSE106129 | GEO
Project description:Bacterial species from diverse phyla contain multiple replicons, yet how these multipartite genomes are organized and segregated during the cell cycle remains poorly understood. Agrobacterium tumefaciens has a 2.8 Mb circular chromosome (Ch1), a 2.1 Mb linear chromosome (Ch2), and two large plasmids (pAt and pTi). We used this alpha proteobacterium as a model to investigate the global organization and temporal segregation of a multipartite genome. Using Chromosome Conformation Capture (Hi-C) assays, we demonstrate that both the circular and the linear chromosomes but neither of the plasmids have their left and right arms juxtaposed from their origins to their termini, generating inter-arm interactions that require the broadly conserved structural maintenance of chromosomes (SMC) complex. Moreover, our studies revealed two types of inter-replicon interactions: “ori-ori clustering” in which the replication origins of all four replicons interact, and “Ch1-Ch2 alignment” in which the arms of Ch1 and Ch2 interact linearly along their lengths. We show that the centromeric proteins (ParB1 for Ch1 and RepBCh2 for Ch2) are required for both types of inter-replicon contacts. Finally, using fluorescence microscopy, we validated the clustering of the origins and observed their frequent colocalization during segregation. Altogether, our findings provide a high-resolution view of the conformation of a multipartite genome. We hypothesize that inter-centromeric contacts promote the organization and maintenance of diverse replicons.
2022-01-30 | GSE182881 | GEO
Project description:Many bacteria, often associated with eukaryotic hosts and of relevance for biotechnological applications, harbor a multipartite genome composed of more than one replicon. Biotechnologically relevant phenotypes are often encoded by genes residing on the secondary replicons. A synthetic biology approach to developing enhanced strains for biotechnological purposes could therefore involve merging pieces or entire replicons from multiple strains into a single genome. Here we report the creation of a genomic hybrid strain in a model multipartite genome species, the plant-symbiotic bacterium Sinorhizobium meliloti. We term this strain as cis-hybrid, since it is produced by genomic material coming from the same species' pangenome. In particular, we moved the secondary replicon pSymA (accounting for nearly 20% of total genome content) from a donor S. meliloti strain to an acceptor strain. The cis-hybrid strain was screened for a panel of complex phenotypes (carbon/nitrogen utilization phenotypes, intra- and extracellular metabolomes, symbiosis, and various microbiological tests). Additionally, metabolic network reconstruction and constraint-based modeling were employed for in silico prediction of metabolic flux reorganization. Phenotypes of the cis-hybrid strain were in good agreement with those of both parental strains. Interestingly, the symbiotic phenotype showed a marked cultivar-specific improvement with the cis-hybrid strains compared to both parental strains. These results provide a proof-of-principle for the feasibility of genome-wide replicon-based remodelling of bacterial strains for improved biotechnological applications in precision agriculture.
2021-03-17 | MTBLS576 | MetaboLights
Project description: Not available
| S-EPMC5940162 | biostudies-literature
Project description:Purpose: Determination of inter- and intra-day variations in tear flow rate, tear fluid protein concentration as well as protein composition regarding their impact for future biomarker studies.Methods: Tear fluid was collected non-invasively from 18 healthy subjects performing Schirmer tests at four different time points repetitive in a period of two days. The tear flow rate with Schirmer test strips was measured. Proteins were extracted from strips and quantified using amino acid analysis. Protein composition was analyzed by data-independent (DIA) based mass spectrometry. To exclude any impairments to health, volunteers underwent a detailed neurological as well as an ophthalmological examination.Results: Whether tear fluid was collected from OS or OD did not affect the tear flow rate (p ≈ 0.63) or protein concentration (p ≈ 0.97) of individual subjects. Moreover, protein concentration was independent from the tear volume, so that a change in volume would only have an effect on total protein amount. When the examination days were compared, investigation of tear flow rate (p ≈ 0.001) and protein concentration (p ≈ 0.0003) indicated significant differences. Further mass spectrometric analysis of tear fluid revealed eleven differentially regulated proteins when comparing both examination days. Conclusion: Our findings provide evidence of inter-day variation in tear flow rate, tear proteome concentration and composition in healthy subjects, suggesting that inter-day variation need to be taken into consideration in biomarker research of tear fluid. Identified proteins were assigned to functions in the immune response, oxidative and reducing processes, as well as mannose metabolism.
2023-10-24 | PXD037811 | Pride
Project description:Assays 1-4: Effects of DnaA activity on S. meliloti chromosome, pSymA and pSymB replicon bias. Sheared DNA extracts of IPTG-induced vs uninduced cultures of DnaA (Assays 1,2) or Hda (Assays 3,4) overexpressors were labeled with Cy3 or Cy5 and hybridized applying dye-swap replicate design. Assay 5: Hybridization of sheared DNA of logarithmic (Cy3-labeled) vs stationary phase (Cy5-labeled) culture.
2015-10-04 | E-MTAB-3924 | biostudies-arrayexpress
Project description:Human papillomavirus (HPV) integration is a critical step in cervical cancer development, while the oncogenic mechanism in genome-wide transcriptional level is still poorly understood. In this study, we employed integrative analysis on multi-omics data of cervical cancer cell lines. Through HPV integration detection, super enhancer (SE) identification, SE-associated gene expression and extrachromosomal DNA (ecDNA) investigation, we aimed to explore the genome-wide transcriptional influence of HPV integration. We identified 5 high-ranking cellular super enhancers generated by HPV integration (the HPV breakpoint induced cellular super enhancers, BP-cSE), leading to intra-chromosomal and inter-chromosomal regulations of chromosomal genes. The pathway analysis showed the dysregulated chromosomal genes were correlated to cervical cancer associated pathways. Importantly, we demonstrated that BP-cSE existed in the HPV-host ecDNA, explaining above transcription alterations. Our results suggest that HPV integration generates cellular super enhancers and functions as ecDNA to regulate unconstraint transcription, expanding the tumorigenic mechanism of HPV integration and providing insights of developing new diagnostic and therapeutic strategies.
2023-04-19 | GSE195631 | GEO
Project description:Human adenovirus type 5 oncogene E1A was shown to induce massive re-replication of cellular DNA in late S phase. Using DNA combing analysis, it was shown that DNA replication dynamics including replicon length, fork velocity and inter-origin distance were dramatically altered in E1A expressing cells as compared to that of normal serum stimulated cells. It was also shown that c-Myc that is induced in E1A expressing cells is essential for the efficient entry of E1A expressing cells into S phase. Serum starved cells were infected with an adenovirus expressing only the transforming E1A protein, and with Adbeta-galactosidase (control) were analyzed by flow cytomery. DNA prepared from such cells were analyzed by DNA combing analysis and data obtained were examined statistically. Requirement of Myc in E1A induced S phase entry was also examined by using antisense Myc vector.
2013-05-22 | E-GEOD-47140 | biostudies-arrayexpress
Project description:S. meliloti strains with a bi- and monopartite genome configuration were constructed by consecutive Cre/lox-mediated site-specific fusions of the secondary replicons. Beside the correct genomic arrangements, these strains and precursors were tested for variations in the nucleotide sequence. Further, a marker frequency analysis was performed to test if replication is initiated at all origins and to determine the replication termination regions of the triple replicon fusion molecule. To gain the sequence data for these analyses, respective strains were applied to whole genome sequencing using an Illumina MiSeq-System.
2022-10-10 | E-MTAB-11878 | biostudies-arrayexpress