Replication Units Research Articles

Green Connections: Adaptive, Integrated, and Nature-Based Solutions for Urban Historic Centres

Choosing adaptation and mitigation actions, through nature-based solutions, fosters the ecological transition process, which is necessary to face the challenges of climate change. However, these interventions are often discontinuous and disconnected, especially within dense and delicate urban fabrics such as historic centres. The research proposes a multi-scalar methodological approach aimed at defining an integrated design tool to improve the microclimatic well-being, accessibility and aesthetic quality of open spaces located in consolidated urban environments. Through the synergy between natural, technological and social components, the aim is to create replicable minimum intervention units designed to foster democratic and ecosystemic connections.

Autophagy plays an antiviral defence role against tomato spotted wilt orthotospovirus and is counteracted by viral effector NSs.

Autophagy, an intracellular degradation process, has emerged as a crucial innate immune response against various plant pathogens, including viruses. Tomato spotted wilt orthotospovirus (TSWV) is a highly destructive plant pathogen that infects over 1000 plant species and poses a significant threat to global food security. However, the role of autophagy in defence against the TSWV pathogen, and whether the virus counteracts this defence, remains unknown. In this study, we report that autophagy plays an important role in antiviral defence against TSWV infection; however, this autophagy-mediated defence is counteracted by the viral effector NSs. Transcriptome profiling revealed the up-regulation of autophagy-related genes (ATGs) upon TSWV infection. Blocking autophagy induction by chemical treatment or knockout/down of ATG5/ATG7 significantly enhanced TSWV accumulation. Notably, the TSWV nucleocapsid (N) protein, a major component of the viral replication unit, strongly induced autophagy. However, the TSWV nonstructural protein NSs was able to effectively suppress N-induced autophagy in a dose-dependent manner. Further investigation revealed that NSs inhibited ATG6-mediated autophagy induction. These findings provide new insights into the defence role of autophagy against TSWV, a representative segmented negative-strand RNA virus, as well as the tospoviral pathogen counterdefence mechanism.

Aptamer-quantum dots platform for SARS-CoV-2 viral particle detection by fluorescence microscopy

The virus is the smallest known replicative unit, usually in nanometer-range sizes. The most simple and sensitive detection assay involves molecular amplification of nucleic acids. This work shows a novel, straightforward detection based on the interaction of viral particles with fluorescent nanoconstructs without using enzymatic amplification, washing or separation steps.Fluorescent nanoconstructs are prepared with individual quantum dots of different emitting green and red fluorescence as a core. They are decorated with aptamers developed to recognise the receptor-binding region of the SARS-CoV-2 spike protein.Nanoconstructs can recognise SARS-CoV-2 viral particles fixed onto a coverglass generating aggregates. Meanwhile, SARS-CoV-2 viral particles/nanoconstructs complexes in solution yield aggregates and complexes, which a fluorescence microscope can visualise. The multiple molecular recognition allowed the detection of SARS-CoV-2 viral particles from a few microliters of patient swabs. This specific SARS-CoV-2/nanoconstructs interaction generates insoluble and precipitating aggregates. By using a mixture of green and red fluorescent nanoconstructs, upon the viral particle interaction, they yield heterochromatic green, red and yellow spectral fluorescence, easily identifiable by a fluorescence microscope. Washing and separation steps are not required, and aggregates allow one to easily recognise them, offering a sensitive, simple, and cheap alternative for viral detection.

Effect of Nano and non-Nano NPK Fertilizers on growth, Yield and Quality of Broccoli (Brassica oleracea var. Italica) Grown under Covered and Un Covered Conditions.

This study included the effects of two planting methods (plastic house and open field) or (covered and uncovered) conditions, three levels of nano NPK fertilizer (approximately 0, 3, 6 g.l-1 ) and three levels of non-nano NPK fertilizer(0, 3, 6 g.l-1 ) were included in this trial (2x3x3=18) with three replicate experimental units (54). Nano and non-nano NPK fertilizers sprayed plants after a week from transplanting and other spraying are donetwo times with an interval of 15 days between each spray.

The Hobby–Eberly Telescope VIRUS Parallel Survey (HETVIPS)* *Based on observations obtained with the Hobby–Eberly Telescope (HET), which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen. The HET is named in honor of its principal benefactors, William P. Hobby and Robert E. Eberly.

The Hobby–Eberly Telescope (HET) VIRUS Parallel Survey (HETVIPS) is a blind spectroscopic program that sparsely covers approximately two-thirds of the celestial sphere and consists of roughly 252 million fiber spectra. The spectra were taken in parallel mode with the Visible Integral-field Replicable Unit Spectrograph (VIRUS) instrument when the HET was observing a primary target with other HET facility instruments. VIRUS can simultaneously obtain approximately 35,000 spectra covering 3470–5540 Å at a spectral resolution of ≈800. Although the vast majority of these spectra cover blank sky, we used the Pan-STARRS1 Data Release 2 Stacked Catalog to identify objects encompassed in the HETVIPS pointings and extract their spectra. This paper presents the first HETVIPS data release, containing 493,012 flux-calibrated spectra obtained through 2023 March 31, as well as a description of the data processing technique. Each of the object spectra were classified, resulting in a catalog of 74,196 galaxies, 4,087 quasars, 259,396 stars, and 154,543 unknown sources.

Comparative disease incidence and prevalence in green and brown varieties of Kappaphycus alvarezii cultivated in Pelakak Village, Lingga District

This study was aimed to analyze the disease incidence and prevalence development of Kappaphycus alvarezii from green and brown varieties. This study used a completely randomized design experimental method with two treatments and four replications. Seaweeds were reared with a longline culture method. The initial weight of seaweeds from each replication unit was 2.70 kg. Incidence and prevalence were observed every day until the 42-th day of culture period. All data obtained were analyzed with an independent t-test. The results showed that there were six incidents of pests and disease attack/infection on two seaweed varieties, namely: (1) Rabbitfish Siganus sp., (2) Epiphytic Filamentous Algae (EFA), (3) Green filamentous algae (Chaetomorpha sp.), (4) Brown seaweeds Sargassum sp., (5) Ice-ice disease, and (6) Fusarium sp. mold. Each attack/infection from six pests and disease was insignificantly different (p>0.05) on both seaweed varieties during observation. The weight gain of green variety slightly increased at 0.15±1.48kg, but the value was lower than brown variety at 0.73±0.39 kg. Therefore, both varieties of K. Alvarezii can be cultured at the same planting period. Pest and disease attacks can be reduced by moving the seaweed to other safer locations.

The Preexplosion Environments and the Progenitor of SN 2023ixf from the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX)

Supernova (SN) 2023ixf was discovered on 2023 May 19. The host galaxy, M101, was observed by the Hobby–Eberly Telescope Dark Energy Experiment collaboration over the period 2020 April 30–2020 July 10, using the Visible Integral-field Replicable Unit Spectrograph (3470 ≲ λ ≲ 5540 Å) on the 10 m Hobby–Eberly Telescope. The fiber filling factor within ±30″ of SN 2023ixf is 80% with a spatial resolution of 1″. The r < 5.″5 surroundings are 100% covered. This allows us to analyze the spatially resolved preexplosion local environments of SN 2023ixf with nebular emission lines. The two-dimensional maps of the extinction and the star formation rate (SFR) surface density (ΣSFR) show weak increasing trends in the radial distributions within the r < 5.″5 regions, suggesting lower values of extinction and SFR in the vicinity of the progenitor of SN 2023ixf. The median extinction and that of the surface density of SFR within r < 3″ are E(B − V) = 0.06 ± 0.14, and There is no significant change in extinction before and after the explosion. The gas metallicity does not change significantly with the separation from SN 2023ixf. The metal-rich branch of the R 23 calculations indicates that the gas metallicity around SN 2023ixf is similar to the solar metallicity (∼Z ☉). The archival deep images from the Canada–France–Hawaii Telescope Legacy Survey (CFHTLS) show a clear detection of the progenitor of SN 2023ixf in the z band at 22.778 ± 0.063 mag, but nondetections in the remaining four bands of CFHTLS (u, g, r, i). The results suggest a massive progenitor of ≈22 M ☉.

Introducing the Texas Euclid Survey for Lyα (TESLA) Survey: Initial Study Correlating Galaxy Properties to Lyα Emission

We present the Texas Euclid Survey for Lyα (TESLA), a spectroscopic survey in the 10 deg2 of the Euclid North Ecliptic Pole (NEP) field. Using TESLA, we study how the physical properties of Lyα emitters (LAEs) correlate with Lyα emission to understand the escape of Lyα emission from galaxies at redshifts of 2–3.5. We present an analysis of 43 LAEs performed in the NEP field using early data from the TESLA survey. We use Subaru Hyper Suprime-Cam imaging in the grizy bands, Spitzer/IRAC channels 1 and 2 from the Hawaii 20 deg2 (H20) survey, and spectra acquired by the Visible Integral-Field Replicable Unit Spectrograph (VIRUS) on the Hobby–Eberly Telescope. We perform spectral energy distribution (SED) fitting to compute the galaxy properties of 43 LAEs, and study correlations between stellar mass, star formation rate (SFR), and dust to the Lyα rest-frame equivalent width (W Lyα ). We uncover marginal (1σ significance) correlations between stellar mass and W Lyα , and SFR and W Lyα , with a Spearman correlation coefficient of −0. and −0., respectively. We show that the W Lyα distribution of the 43 LAEs is consistent with being drawn from an exponential distribution with an e-folding scale of W 0 = 150 Å. Once complete the TESLA survey will enable the study of ≳50,000 LAEs to explore more correlations between galaxy properties and W Lyα . The large sample size will allow the construction of a predictive model for W Lyα as a function of SED-derived galaxy properties, which could be used to improve Lyα-based constraints on reionization.

Understanding Chromosome Replication and Segregation Unit of Mycobacterium and Its Comparative Analysis with Model Organisms: From Drug Targets to Drug Identification

Bacterium maintains its pathogenicity in the host by continuing replication and adopting temporal and spatial coordination of cell division steps such as cell wall synthesis, DNA replication, chromosome segregation, Z ring assembly, septum formation and finally cytokinesis. This multistep process requires spatiotemporal assembly of macromolecular complexes and is probably regulated by redundant and multifunctional activities of cell replication and division proteins. Two macromolecular assemblies of peptidoglycan biosynthesis, known as elongasome and divisome are known to drive the division of mother cell into two daughter cells and are characterized by the presence of signature protein complexes. Though the exact composition of macromolecular complexes is yet to be defined in Mycobacterium, the presence of some conserved proteins demonstrates the preservation of elementary units. Along with elongasome and divisome complexes, chromosome replication and segregation proteins are very important to understand as these proteins are very essential for bacilli survival, sustenance, and pathogenesis. In this review, along with presenting the differential features of Mycobacterium cell division process, we are comparing chromosome replication and segregation proteins of Mycobacterium with other bacterial species as we aim to identify structural and functional differences between these proteins in different species. In this review, we have also listed the potential drugs that can be tested to target Mycobacterium chromosome replication and segregation proteins. We expect that based on these differences identified, researchers would be able to direct their research in the characterization of Mycobacterium specific drug.

MatPSST: A Matlab/Simulink‐based power system simulation toolbox for research and education

AbstractThis paper presents an open‐access Matlab/Simulink‐based power system simulation toolbox (MatPSST) for research and education. In MatPSST, dynamic modeling is implemented by Simulink. Only the initialization process is coded in Matlab. This structure makes full use of Simulink, enabling users to fully use the rich solvers and built‐in toolboxes in Matlab/Simulink, such as small‐signal analysis, without additional programming. The interaction with real‐time platforms like RTLAB and dSPACE in MatPSST is convenient through the Simulink interface. In addition, MatPSST provides a uniform interface and flexible framework for user‐defined functions. Users do not need to consider the interaction between models and dynamic solvers when implementing state‐of‐the‐art user‐defined models. To avoid the heavy work (replicate units and change parameters) in modeling detailed wind farm or photovoltaic station with hundreds of renewable generation units, the idea of the vector‐variable‐based model is proposed with MatPSST. Case studies introduce some selected application examples of MatPSST in research and education and demonstrate its accuracy by the comparisons with Simscape and PSAT. The cases reveal the advantages of MatPSST in promoting power system research and education.

Hollow-fibre system model of tuberculosis reproducibility and performance specifications for best practice in drug and combination therapy development.

The hollow-fibre system model of tuberculosis (HFS-TB) has been endorsed by regulators; however, application of HFS-TB requires a thorough understanding of intra- and inter-team variability, statistical power and quality controls. Three teams evaluated regimens matching those in the Rapid Evaluation of Moxifloxacin in Tuberculosis (REMoxTB) study, plus two high-dose rifampicin/pyrazinamide/moxifloxacin regimens, administered daily for up to 28 or 56 days against Mycobacterium tuberculosis (Mtb) under log-phase growth, intracellular growth or semidormant growth under acidic conditions. Target inoculum and pharmacokinetic parameters were pre-specified, and the accuracy and bias at achieving these calculated using percent coefficient of variation (%CV) at each sampling point and two-way analysis of variance (ANOVA). A total of 10 530 individual drug concentrations, and 1026 individual cfu counts were measured. The accuracy in achieving intended inoculum was >98%, and >88% for pharmacokinetic exposures. The 95% CI for the bias crossed zero in all cases. ANOVA revealed that the team effect accounted for <1% of variation in log10 cfu/mL at each timepoint. The %CV in kill slopes for each regimen and different Mtb metabolic populations was 5.10% (95% CI: 3.36%-6.85%). All REMoxTB arms exhibited nearly identical kill slopes whereas high dose regimens were 33% faster. Sample size analysis revealed that at least three replicate HFS-TB units are needed to identify >20% difference in slope, with a power of >99%. HFS-TB is a highly tractable tool for choosing combination regimens with little variability between teams, and between replicates.

Menilik Memetika sebagai Koleksi Baru Teori Kebudayaan

Evolution process not only occurs in the biological area, but also in the cultural area. On the one hand, from one of the evolution theories, it has been known that the unit of replication is gene. On the other hand, the unit of transmission and replication in the cultural evolution can be associated with meme. Similar to genes that propagate themselves through a process called reproduction, memes also propagate themselves from person to person through a process called imitation. By way of imitation, memetic theory explains the development and the evolution of a culture. Imitating others points to the phenomena where ideas, information, behaviour, things, or style are passed on or spread/repeated by certain people. The process in which cultural elements (memes) are passed onto other groups can be considered as a sort of cultural transmission. Memes propagate for themselves and in this way they survive and exist in the human culture. Human mind has the ability for imitating information and ideas, therefore a human being is seen as an agent of meme evolution. Memes are spread out through human interactions and the various kinds of media. In this sense, culture will always be in the state of developing and changing.

Cohesin-dependent chromosome loop extrusion is limited by transcription and stalled replication forks.

Genome function depends on regulated chromosome folding, and loop extrusion by the protein complex cohesin is essential for this multilayered organization. The chromosomal positioning of cohesin is controlled by transcription, and the complex also localizes to stalled replication forks. However, the role of transcription and replication in chromosome looping remains unclear. Here, we show that reduction of chromosome-bound RNA polymerase weakens normal cohesin loop extrusion boundaries, allowing cohesin to form new long-range chromosome cis interactions. Stress response genes induced by transcription inhibition are also shown to act as new loop extrusion boundaries. Furthermore, cohesin loop extrusion during early S phase is jointly controlled by transcription and replication units. Together, the results reveal that replication and transcription machineries are chromosome-folding regulators that block the progression of loop-extruding cohesin, opening for new perspectives on cohesin’s roles in genome function and stability.

High diversity in the regulatory region of Shiga toxin encoding bacteriophages

BackgroundEnterohemorrhagic Escherichia coli (EHEC) is an emerging health challenge worldwide and outbreaks caused by this pathogen poses a serious public health concern. Shiga toxin (Stx) is the major virulence factor of EHEC, and the stx genes are carried by temperate bacteriophages (Stx phages). The switch between lysogenic and lytic life cycle of the phage, which is crucial for Stx production and for severity of the disease, is regulated by the CI repressor which maintain latency by preventing transcription of the replication proteins. Three EHEC phage replication units (Eru1-3) in addition to the classical lambdoid replication region have been described previously, and Stx phages carrying the Eru1 replication region were associated with highly virulent EHEC strains.ResultsIn this study, we have classified the Eru replication region of 419 Stx phages. In addition to the lambdoid replication region and three already described Erus, ten novel Erus (Eru4 to Eru13) were detected. The lambdoid type, Eru1, Eru4 and Eru7 are widely distributed in Western Europe. Notably, EHEC strains involved in severe outbreaks in England and Norway carry Stx phages with Eru1, Eru2, Eru5 and Eru7 replication regions. Phylogenetic analysis of CI repressors from Stx phages revealed eight major clades that largely separate according to Eru type.ConclusionThe classification of replication regions and CI proteins of Stx phages provides an important platform for further studies aimed to assess how characteristics of the replication region influence the regulation of phage life cycle and, consequently, the virulence potential of the host EHEC strain.

A flavivirus-inducible gene expression system that modulates broad-spectrum antiviral activity against dengue and Zika viruses

Incidence of dengue virus (DENV) and Zika virus (ZIKV), two mosquito-borne flaviviruses, is increasing in large parts of the world. Vaccination and medication for these diseases are unsatisfactory. Here, we developed a novel antiviral approach, using a virus-inducible gene expression system, to block virus replication and transmission. Constructs containing the smallest replication units of dengue virus serotype 2 (DENV2) with negative-stranded DENV2 artificial genomes and genes of interest were established in an Aedes aegypti cell line, resulting in expression of target genes after DENV2 infection. Green fluorescent protein (GFP) assays confirmed the system was virus-inducible. When we used one of two apoptosis-related genes, A. aegypti michelob_x (AaMx) and inhibitor of apoptosis (IAP)-antagonist michelob_x-like protein (AaIMP) instead of GFP, the production of viral RNA and proteins were inhibited for all five viruses tested (DENV1–4 and ZIKV), and effector caspase activity was induced. The system thus inhibited the production of infectious virus particles in vitro, and in mosquitoes it did so after DENV2 infection. This is a novel broad-spectrum antiviral approach using a flavivirus-inducible gene-expression system, which could lead to new avenues for mosquito-borne disease control.

Lab-on-Chip for In Situ Analysis of Nutrients in the Deep Sea

Microfluidic reagent-based nutrient sensors offer a promising technology to address the global undersampling of ocean chemistry but have so far not been shown to operate in the deep sea (>200 m). We report a new family of miniaturized lab-on-chip (LOC) colorimetric analyzers making in situ nitrate and phosphate measurements from the surface ocean to the deep sea (>4800 m). This new technology gives users a new low-cost, high-performance tool for measuring chemistry in hyperbaric environments. Using a combination of laboratory verification and field-based tests, we demonstrate that the analyzers are capable of in situ measurements during profiling that are comparable to laboratory-based analyses. The sensors feature a novel and efficient inertial-flow mixer that increases the mixing efficiency and reduces the back pressure and flushing time compared to a previously used serpentine mixing channel. Four separate replicate units of the nitrate and phosphate sensor were calibrated in the laboratory and showed an average limit of detection of 0.03 μM for nitrate and 0.016 μM for phosphate. Three on-chip optical absorption cell lengths provide a large linear range (to >750 μM (10.5 mg/L-N) for nitrate and >15 μM (0.47 mg/L-P) for phosphate), making the instruments suitable for typical concentrations in both ocean and freshwater aquatic environments. The LOC systems automatically collected a series of deep-sea nitrate and phosphate profiles in the northeast Atlantic while attached to a conductivity temperature depth (CTD) rosette, and the LOC nitrate sensor was attached to a PROVOR profiling float to conduct automated nitrate profiles in the Mediterranean Sea.

МОТИВ КАК ИДЕАЛЬНЫЙ ТИП, ИЛИ ТРИКСТЕРСКИЕ ЭПИЗОДЫ В ЕВРАЗИЙСКОМ ФОЛЬКЛОРЕ

Folklore motif is an analytical tool created for the particular kind of research. Our purpose is to reveal routes of the interregional exchange of ideas in different periods of the past. The dissemination of ideas can be followed when we study material (archaeological sites) and nonmaterial (traditional narratives) objects created because of particular ideas adopted by people. Ideas are copied and disseminated unconsciously. The folklore motif is any unit of replication (most often an episode or an image) registered in two or more traditions. The tradition is a totality of narratives recorded for a particular ethnic group or across a particular territory. Motifs can be classified according to thematic groups that approximately correspond to genres of those narratives from which they are selected. The author analyses the results of computing trickster motifs with animal and anthropomorphic actors. The area configuration of the selected interaction spheres suggests that the spread of the motifs with anthropomorphic actors took place mostly from the late Antique period to the early New Time, and the spread of the animal tales – during the Middle Age and earlier. The influence of the Great Steppe on East Europe is noticeable for the Middle Age with the emergence of the borderline between Christian Europe, and the Asian-Africa interaction sphere is a characteristic trait of the early New Time. China is outside of this opposition.

Susceptibility of iris (Iridaceae) to larval infestation by Neorthacheta dissimilis (Diptera: Scathophagidae)

Abstract Neorthacheta dissimilis Malloch (Diptera: Scathophagidae) is a poorly known scathophagid fly that feeds and develops on iris (Iridaceae). A survey of its occurrence was performed at the Montréal Botanical Garden (Montréal, Québec, Canada) in 2018, 2019, and 2020. Iris species and cultivars from two subgenera, Iris and Limniris, were evaluated for larval infestation. When pooled for subgenera and years, data from 18 Iris classes revealed high levels of infestation per flower stalk, ranging from 34% to 100%. When analysed per bud or flower, levels of infestation remained high, ranging from 19% to 100%, but generally was lower than for flower stalks as the unit of replication. The mean number of N. dissimilis larvae per infested flower or bud was higher for the subgenus Limniris (1.13) than for the subgenus Iris (1.03), with a maximum of four N. dissimilis larvae per flower being observed. These figures are worrying for horticulturalists because the insect is prevalent and causes either abortion or aesthetic damages to iris flowers.

The HETDEX Instrumentation: Hobby–Eberly Telescope Wide-field Upgrade and VIRUS

Abstract The Hobby–Eberly Telescope (HET) Dark Energy Experiment (HETDEX) is undertaking a blind wide-field low-resolution spectroscopic survey of 540 deg2 of sky to identify and derive redshifts for a million Lyα-emitting galaxies in the redshift range 1.9 &lt; z &lt; 3.5. The ultimate goal is to measure the expansion rate of the universe at this epoch, to sharply constrain cosmological parameters and thus the nature of dark energy. A major multiyear Wide-Field Upgrade (WFU) of the HET was completed in 2016 that substantially increased the field of view to 22′ diameter and the pupil to 10 m, by replacing the optical corrector, tracker, and Prime Focus Instrument Package and by developing a new telescope control system. The new, wide-field HET now feeds the Visible Integral-field Replicable Unit Spectrograph (VIRUS), a new low-resolution integral-field spectrograph (LRS2), and the Habitable Zone Planet Finder, a precision near-infrared radial velocity spectrograph. VIRUS consists of 156 identical spectrographs fed by almost 35,000 fibers in 78 integral-field units arrayed at the focus of the upgraded HET. VIRUS operates in a bandpass of 3500−5500 Å with resolving power R ≃ 800. VIRUS is the first example of large-scale replication applied to instrumentation in optical astronomy to achieve spectroscopic surveys of very large areas of sky. This paper presents technical details of the HET WFU and VIRUS, as flowed down from the HETDEX science requirements, along with experience from commissioning this major telescope upgrade and the innovative instrumentation suite for HETDEX.

Complete genomic sequence and phylogenomics analysis of Agrobacterium strain AB2/73: a new Rhizobium species with a unique mega-Ti plasmid

BackgroundThe Agrobacterium strain AB2/73 has a unique host range for the induction of crown gall tumors, and contains an exceptionally large, over 500 kbp mega Ti plasmid. We used whole genome sequencing to fully characterize and comparatively analyze the complex genome of strain AB2/73, including its Ti plasmid and virulence factors.ResultsWe obtained a high-quality, full genomic sequence of AB2/73 by a combination of short-read Illumina sequencing and long-read Nanopore sequencing. The AB2/73 genome has a total size of 7,266,754 bp with 59.5% GC for which 7012 genes (6948 protein coding sequences) are predicted. Phylogenetic and comparative genomics analysis revealed that strain AB2/73 does not belong to the genus Agrobacterium, but to a new species in the genus Rhizobium, which is most related to Rhizobium tropici. In addition to the chromosome, the genome consists of 6 plasmids of which the largest two, of more than 1 Mbp, have chromid-like properties. The mega Ti plasmid is 605 kbp in size and contains two, one of which is incomplete, repABC replication units and thus appears to be a cointegrate consisting of about 175 kbp derived from an unknown Ti plasmid linked to 430 kbp from another large plasmid. In pTiAB2/73 we identified a complete set of virulence genes and two T-DNAs. Besides the previously described T-DNA we found a larger, second T-DNA containing a 6b-like onc gene and the acs gene for agrocinopine synthase. Also we identified two clusters of genes responsible for opine catabolism, including an acc-operon for agrocinopine degradation, and genes putatively involved in ridéopine catabolism. The plasmid also harbours tzs, iaaM and iaaH genes for the biosynthesis of the plant growth regulators cytokinin and auxin.ConclusionsThe comparative genomics analysis of the high quality genome of strain AB2/73 provided insight into the unusual phylogeny and genetic composition of the limited host range Agrobacterium strain AB2/73. The description of its unique genomic composition and of all the virulence determinants in pTiAB2/73 will be an invaluable tool for further studies into the special host range properties of this bacterium.