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Nissimov JI, Jones M, Napier JA, Munn CB, Kimmance SA, Allen MJ. Functional inferences of environmental coccolithovirus biodiversity. Virol Sin 2013; 28:291-302. [PMID: 24006045 DOI: 10.1007/s12250-013-3362-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 08/12/2013] [Indexed: 11/25/2022] Open
Abstract
The cosmopolitan calcifying alga Emiliania huxleyi is one of the most abundant bloom forming coccolithophore species in the oceans and plays an important role in global biogeochemical cycling. Coccolithoviruses are a major cause of coccolithophore bloom termination and have been studied in laboratory, mesocosm and open ocean studies. However, little is known about the dynamic interactions between the host and its viruses, and less is known about the natural diversity and role of functionally important genes within natural coccolithovirus communities. Here, we investigate the temporal and spatial distribution of coccolithoviruses by the use of molecular fingerprinting techniques PCR, DGGE and genomic sequencing. The natural biodiversity of the virus genes encoding the major capsid protein (MCP) and serine palmitoyltransferase (SPT) were analysed in samples obtained from the Atlantic Meridional Transect (AMT), the North Sea and the L4 site in the Western Channel Observatory. We discovered nine new coccolithovirus genotypes across the AMT and L4 site, with the majority of MCP sequences observed at the deep chlorophyll maximum layer of the sampled sites on the transect. We also found four new SPT gene variations in the North Sea and at L4. Their translated fragments and the full protein sequence of SPT from laboratory strains EhV-86 and EhV-99B1 were modelled and revealed that the theoretical fold differs among strains. Variation identified in the structural distance between the two domains of the SPT protein may have an impact on the catalytic capabilities of its active site. In summary, the combined use of 'standard' markers (i.e. MCP), in combination with metabolically relevant markers (i.e. SPT) are useful in the study of the phylogeny and functional biodiversity of coccolithoviruses, and can provide an interesting intracellular insight into the evolution of these viruses and their ability to infect and replicate within their algal hosts.
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Foss K, da Costa RC, Rajala-Schuttz PJ, Rajala-Shultz PJ, Allen MJ. Force plate gait analysis in Doberman Pinschers with and without cervical spondylomyelopathy. J Vet Intern Med 2012; 27:106-11. [PMID: 23278957 DOI: 10.1111/jvim.12025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 09/13/2012] [Accepted: 10/23/2012] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND The most accepted means of evaluating the response of a patient with cervical spondylomyelopathy (CSM) to treatment is subjective and based on the owner and clinician's perception of the gait. OBJECTIVE To establish and compare kinetic parameters based on force plate gait analysis between normal and CSM-affected Dobermans. ANIMALS Nineteen Doberman Pinschers: 10 clinically normal and 9 with CSM. METHODS Force plate analysis was prospectively performed in all dogs. At least 4 runs of ipsilateral limbs were collected from each dog. Eight force platform parameters were evaluated, including peak vertical force (PVF) and peak vertical impulse (PVI), peak mediolateral force (PMLF) and peak mediolateral impulse, peak braking force and peak braking impulse, and peak propulsive force (PPF) and peak propulsive impulse. In addition, the coefficient of variation (CV) for each limb was calculated for each parameter. Data analysis was performed by a repeated measures approach. RESULTS PMLF (P = .0062), PVI (P = .0225), and PPF (P = .0408) were found to be lower in CSM-affected dogs compared with normal dogs. Analysis by CV as the outcome indicated more variability in PVF in CSM-affected dogs (P = 0.0045). The largest difference in the CV of PVF was seen in the thoracic limbs of affected dogs when compared with the thoracic limbs of normal dogs (P = 0.0019). CONCLUSIONS AND CLINICAL IMPORTANCE The CV of PVF in all 4 limbs, especially the thoracic limbs, distinguished clinically normal Dobermans from those with CSM. Other kinetic parameters less reliably distinguished CSM-affected from clinically normal Dobermans.
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Zhao Q, Allen MJ, Wang Y, Wang B, Wang N, Shi L, Sitrin RD. Disassembly and reassembly improves morphology and thermal stability of human papillomavirus type 16 virus-like particles. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2012; 8:1182-9. [DOI: 10.1016/j.nano.2012.01.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 12/29/2011] [Accepted: 01/18/2012] [Indexed: 10/14/2022]
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Pagarete A, Lanzén A, Puntervoll P, Sandaa RA, Larsen A, Larsen JB, Allen MJ, Bratbak G. Genomic sequence and analysis of EhV-99B1, a new coccolithovirus from the Norwegian fjords. Intervirology 2012; 56:60-6. [PMID: 22986606 DOI: 10.1159/000341611] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 07/02/2012] [Indexed: 11/19/2022] Open
Abstract
Coccolithoviruses are giant dsDNA viruses that infect Emiliania huxleyi, the most ubiquitous marine microalga. Here, we present the genome of the latest coccolithovirus strain to be sequenced, EhV-99B1, and compare it with two other coccolithovirus genomes (EhV-86 and EhV-163). EhV-99B1 shares a pairwise nucleotide identity of 98% with EhV-163 (the two strains were isolated from the same Norwegian fjord but in different years), and just 96.5% with EhV-86 (isolated in the same spring as EhV-99B1 but in the English Channel). We confirmed and extended the list of relevant genomic differences between these EhVs from the Norwegian fjord and EhVs from the English Channel, namely the removal/insertions of: a phosphate permease, an endonuclease, a transposase, and two specific tRNAs. As a whole, this study provided new clues and insights into the diversity and mechanisms driving the evolution of these large oceanic viruses, in particular those processes involving selfish genetic elements.
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Abstract
Total joint replacement is now considered a routine surgical option for small animals with advanced joint disease. This review highlights the current state of the art in total hip, elbow and knee replacement in small animals, as well as the potential for application to other joints such as the intervertebral discs, hock and shoulder. Advances in cementless fixation, the use of less-invasive, bone-sparing procedures, and the development of custom implant options for revision surgery and oncologic reconstruction will be discussed. As growth in this field continues, it is important that future developments in total joint replacement are built on a foundation of detailed laboratory evaluation of new implant designs and surgical techniques, objective assessment of clinical outcomes, and a comprehensive, coordinated retrieval program that evaluates both well-functioning and failed joint replacements.
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Jensen CN, Cartwright J, Ward J, Hart S, Turkenburg JP, Ali ST, Allen MJ, Grogan G. A flavoprotein monooxygenase that catalyses a Baeyer-Villiger reaction and thioether oxidation using NADH as the nicotinamide cofactor. Chembiochem 2012; 13:872-8. [PMID: 22416037 DOI: 10.1002/cbic.201200006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Indexed: 11/10/2022]
Abstract
A gene from the marine bacterium Stenotrophomonas maltophilia encodes a 38.6 kDa FAD-containing flavoprotein (Uniprot B2FLR2) named S. maltophilia flavin-containing monooxygenase (SMFMO), which catalyses the oxidation of thioethers and also the regioselective Baeyer-Villiger oxidation of the model substrate bicyclo[3.2.0]hept-2-en-6-one. The enzyme was unusual in its ability to employ either NADH or NADPH as nicotinamide cofactor. The K(M) and k(cat) values for NADH were 23.7±9.1 μM and 0.029 s(-1) and 27.3±5.3 μM and 0.022 s(-1) for NADPH. However, k(cat) /K(M) value for the ketone substrate in the presence of 100 μM cofactor was 17 times greater for NADH than for NADPH. SMFMO catalysed the quantitative conversion of 5 mM ketone in the presence of substoichiometric concentrations of NADH with the formate dehydrogenase cofactor recycling system, to give the 2-oxa and 3-oxa lactone products of Baeyer-Villiger reaction in a ratio of 5:1, albeit with poor enantioselectivity. The conversion with NADPH was 15 %. SMFMO also catalysed the NADH-dependent transformation of prochiral aromatic thioethers, giving in the best case, 80 % ee for the transformation of p-chlorophenyl methyl sulfide to its R enantiomer. The structure of SMFMO reveals that the relaxation in cofactor specificity appears to be accomplished by the substitution of an arginine residue, responsible for recognition of the 2'-phosphate on the NADPH ribose in related NADPH-dependent FMOs, with a glutamine residue in SMFMO. SMFMO is thus representative of a separate class of single-component, flavoprotein monooxygenases that catalyse NADH-dependent oxidations from which possible sequences and strategies for developing NADH-dependent biocatalysts for asymmetric oxygenation reactions might be identified.
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Borthwick AD, Liddle J, Davies DE, Exall AM, Hamlett C, Hickey DM, Mason AM, Smith IED, Nerozzi F, Peace S, Pollard D, Sollis SL, Allen MJ, Woollard PM, Pullen MA, Westfall TD, Stanislaus DJ. Pyridyl-2,5-Diketopiperazines as Potent, Selective, and Orally Bioavailable Oxytocin Antagonists: Synthesis, Pharmacokinetics, and In Vivo Potency. J Med Chem 2012; 55:783-96. [DOI: 10.1021/jm201287w] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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83
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Nissimov JI, Worthy CA, Rooks P, Napier JA, Kimmance SA, Henn MR, Ogata H, Allen MJ. Draft genome sequence of the coccolithovirus EhV-84. Stand Genomic Sci 2011; 5:1-11. [PMID: 22180805 PMCID: PMC3236045 DOI: 10.4056/sigs.1884581] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Coccolithoviridae is a recently discovered group of viruses that infect the marine coccolithophorid Emiliania huxleyi. Emiliania huxleyi virus 84 (EhV-84) has a 160 -180 nm diameter icosahedral structure and a genome of approximately 400 kbp. Here we describe the structural and genomic features of this virus, together with a near complete draft genome sequence (~99%) and its annotation. This is the fourth genome sequence of a member of the coccolithovirus family.
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Pagarete A, Corguillé G, Tiwari B, Ogata H, Vargas C, Wilson WH, Allen MJ. Unveiling the transcriptional features associated with coccolithovirus infection of natural Emiliania huxleyi blooms. FEMS Microbiol Ecol 2011; 78:555-64. [PMID: 22066669 DOI: 10.1111/j.1574-6941.2011.01191.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 08/01/2011] [Accepted: 08/12/2011] [Indexed: 11/27/2022] Open
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85
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Allen MJ, Lacroix JJ, Ramachandran S, Capone R, Whitlock JL, Ghadge GD, Arnsdorf MF, Roos RP, Lal R. Mutant SOD1 forms ion channel: implications for ALS pathophysiology. Neurobiol Dis 2011; 45:831-8. [PMID: 21930207 DOI: 10.1016/j.nbd.2011.08.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 08/18/2011] [Accepted: 08/31/2011] [Indexed: 10/17/2022] Open
Abstract
Point mutations in the gene encoding copper-zinc superoxide dismutase (SOD1) impart a gain-of-function to this protein that underlies 20-25% of all familial amyotrophic lateral sclerosis (FALS) cases. However, the specific mechanism of mutant SOD1 toxicity has remained elusive. Using the complementary techniques of atomic force microscopy (AFM), electrophysiology, and cell and molecular biology, here we examine the structure and activity of A4VSOD1, a mutant SOD1. AFM of A4VSOD1 reconstituted in lipid membrane shows discrete tetrameric pore-like structure with outer and inner diameters 12.2 and 3.0nm respectively. Electrophysiological recordings show distinct ionic conductances across bilayer for A4VSOD1 and none for wildtype SOD1. Mouse neuroblastoma cells exposed to A4VSOD1 undergo membrane depolarization and increases in intracellular calcium. These results provide compelling new evidence that a mutant SOD1 is capable of disrupting cellular homeostasis via an unregulated ion channel mechanism. Such a "toxic channel" mechanism presents a new therapeutic direction for ALS research.
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Allen MJ, Gemel J, Beyer EC, Lal R. Atomic force microscopy of Connexin40 gap junction hemichannels reveals calcium-dependent three-dimensional molecular topography and open-closed conformations of both the extracellular and cytoplasmic faces. J Biol Chem 2011; 286:22139-46. [PMID: 21543330 PMCID: PMC3121358 DOI: 10.1074/jbc.m111.240002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 04/19/2011] [Indexed: 11/06/2022] Open
Abstract
Atomic force microscopy was used to study the three-dimensional molecular topography and calcium-sensitive conformational changes of Connexin40 hemichannels (connexons) reconstituted in 1,2-dioeloyl-sn-glycero-3-phosphatidylcholine lipid bilayers. Two classes of objects were observed that differed in their protrusion heights above the bilayer (2.6 versus 4.2 nm). Comparison to reconstituted connexons containing Connexin40 truncated to eliminate most of its C-terminal cytoplasmic domain showed that the two height classes corresponded to the shorter extracellular and taller cytoplasmic aspects of the hemichannels and that the C-terminal tail of Connexin40 contributes ∼1.6 nm in thickness. Hemichannels imaged in solutions containing < 10 μm Ca(2+) showed 3.1-3.2 nm depressions (openings) in 30% of the cytoplasmic faces and 65% of the extracellular faces, and high-resolution three-dimensional topography of extracellular or cytoplasmic aspects of some connexons was observed. After addition of 3.6 mm Ca(2+), > 75% of the connexons in either orientation adopted closed conformations. In contrast, hemichannels imaged in the presence of 0.1 mm EDTA showed large (5.6- to 5.8-nm diameter) openings in nearly all hemichannels regardless of orientation, and detailed topography was visible in many connexons. Real-time imaging following the addition of 3.6 mm Ca(2+) showed transitions of both extracellular and cytoplasmic orientations from "open" into "closed" conformations within several minutes. These studies provide the first high-resolution topographic information regarding a connexin with a large cytoplasmic domain and suggest that the extramembranous portions of Connexin40 contribute to a channel entrance that is relaxed by chelation of residual divalent cations.
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Brown JS, Wheeler PC, Boyd KT, Barnes MR, Allen MJ. Chronic exertional compartment syndrome of the forearm: a case series of 12 patients treated with fasciotomy. J Hand Surg Eur Vol 2011; 36:413-9. [PMID: 21339238 DOI: 10.1177/1753193410397900] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Chronic exertional compartment syndrome of the forearm is rare in the published literature. We report the outcome of a series of 12 patients treated with fasciotomy over a 14 year period. All patients underwent dynamic intra-compartmental pressure testing using a slit catheter technique before surgery. Raised intra-compartmental pressures on exercise, typical symptoms and the absence of other diagnoses were criteria for offering surgical intervention. The superficial flexor, deep flexor and extensor compartments were released. Median follow-up was 9.5 years (range 7 months to 12 years). Median patient-reported percentage improvement after surgery was 88% (range 0%-100%). Median time to return to full activity was 9 weeks. Eleven out of 12 patients were satisfied, very satisfied or extremely satisfied with the outcome of surgery. Fasciotomy can be an effective treatment for chronic exertional compartment syndrome of the forearm.
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Sayanova O, Haslam RP, Calerón MV, López NR, Worthy C, Rooks P, Allen MJ, Napier JA. Identification and functional characterisation of genes encoding the omega-3 polyunsaturated fatty acid biosynthetic pathway from the coccolithophore Emiliania huxleyi. PHYTOCHEMISTRY 2011; 72:594-600. [PMID: 21316718 DOI: 10.1016/j.phytochem.2011.01.022] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 01/11/2011] [Accepted: 01/12/2011] [Indexed: 05/30/2023]
Abstract
The Prymnesiophyceae coccolithophore Emiliania huxleyi is one of the most abundant alga in our oceans and therefore plays a central role in marine foodwebs. E. huxleyi is notable for the synthesis and accumulation of the omega-3 long chain polyunsaturated fatty acid docosahexaenoic acid (DHA; 22:6Δ(4,7,10,13,16,19), n-3) which is accumulated in fish oils and known to have health-beneficial properties to humans, preventing cardiovascular disease and related pathologies. Here we describe the identification and functional characterisation of the five E. huxleyi genes which direct the synthesis of docosahexaenoic acid in this alga. Surprisingly, E. huxleyi does not use the conventional Δ6-pathway, instead using the alternative Δ8-desaturation route which has previously only been observed in a few unrelated microorganisms. Given that E. huxleyi accumulates significant levels of the Δ6-desaturated fatty acid stearidonic acid (18:4Δ(6,9,12,15), n-3), we infer that the biosynthesis of DHA is likely to be metabolically compartmentalised from the synthesis of stearidonic acid.
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Allen MJ, Lanzén A, Bratbak G. Characterisation of the coccolithovirus intein. Mar Genomics 2010; 4:1-7. [PMID: 21429459 DOI: 10.1016/j.margen.2010.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 11/01/2010] [Accepted: 11/02/2010] [Indexed: 11/17/2022]
Abstract
The identification of inteins in viral genomes is becoming increasingly common. Inteins are selfish DNA elements found within coding regions of host proteins. Following translation, they catalyse their own excision and the formation of a peptide bond between the flanking protein regions. Many inteins also display homing endonuclease function. Here, the newly identified coccolithovirus intein is described and is predicted to have both self-splicing and homing endonuclease activity. The biochemical mechanism of its protein splicing activity is hypothesised, and the prevalence of the intein among natural coccolithovirus isolates is tested.
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Hajat S, Sheridan SC, Allen MJ, Pascal M, Laaidi K, Yagouti A, Bickis U, Tobias A, Bourque D, Armstrong BG, Kosatsky T. Heat-health warning systems: a comparison of the predictive capacity of different approaches to identifying dangerously hot days. Am J Public Health 2010; 100:1137-44. [PMID: 20395585 DOI: 10.2105/ajph.2009.169748] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES We compared the ability of several heat-health warning systems to predict days of heat-associated mortality using common data sets. METHODS Heat-health warning systems initiate emergency public health interventions once forecasts have identified weather conditions to breach predetermined trigger levels. We examined 4 commonly used trigger-setting approaches: (1) synoptic classification, (2) epidemiologic assessment of the temperature-mortality relationship, (3) temperature-humidity index, and (4) physiologic classification. We applied each approach in Chicago, Illinois; London, United Kingdom; Madrid, Spain; and Montreal, Canada, to identify days expected to be associated with the highest heat-related mortality. RESULTS We found little agreement across the approaches in which days were identified as most dangerous. In general, days identified by temperature-mortality assessment were associated with the highest excess mortality. CONCLUSIONS Triggering of alert days and ultimately the initiation of emergency responses by a heat-health warning system varies significantly across approaches adopted to establish triggers.
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91
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Allen MJ, Rudd RE, McElfresh MW, Balhorn R. Time-dependent measure of a nanoscale force-pulse driven by the axonemal dynein motors in individual live sperm cells. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2010; 6:510-5. [PMID: 20060073 DOI: 10.1016/j.nano.2009.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Revised: 11/06/2009] [Accepted: 12/16/2009] [Indexed: 10/20/2022]
Abstract
Nanoscale mechanical forces generated by motor proteins are crucial to normal cellular and organismal functioning. The ability to measure and exploit such forces is important to developing motile biomimetic nanodevices powered by biological motors for nanomedicine. Axonemal dynein motors positioned inside the sperm flagellum drive microtubule sliding and give rise to rhythmic beating. This force-generating action pushes the sperm cell through viscous media. Here we report new nanoscale information on how the propulsive force is generated by the sperm flagellum and how this force varies over time. Using a modified atomic force microscope, single-cell recordings reveal discrete approximately 50-ms pulses oscillating with amplitude 9.8 +/- 2.6 nN independent of pulse frequency (3.5-19.5 Hz). The average work carried out by each cell is 4.6 x 10(-16) J per pulse, equivalent to the hydrolysis of approximately 5500 molecules of adenosine triphosphate. The mechanochemical coupling at each active dynein head is approximately 2.2 pN per adenosine triphosphate molecule and approximately 3.9 pN per dynein arm. From the clinical editor: In this paper, nanoscale mechanical forces generated by axonemal dynein motors derived from sperm flagellum are examined and reported. These motor proteins are crucial to normal cellular and organismal functioning. The ability to measure and exploit such forces is important to developing motile biomimetic nanodevices powered by biological motors for nanomedicine.
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Pagarete A, Allen MJ, Wilson WH, Kimmance SA, de Vargas C. Host-virus shift of the sphingolipid pathway along anEmiliania huxleyibloom: survival of the fattest. Environ Microbiol 2009; 11:2840-8. [PMID: 19638172 DOI: 10.1111/j.1462-2920.2009.02006.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Weynberg KD, Allen MJ, Ashelford K, Scanlan DJ, Wilson WH. From small hosts come big viruses: the complete genome of a secondOstreococcus taurivirus, OtV-1. Environ Microbiol 2009; 11:2821-39. [PMID: 19650882 DOI: 10.1111/j.1462-2920.2009.01991.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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94
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Allen MJ, McLean-Veysey P. Interaction between clopidogrel and proton pump inhibitors. CMAJ 2009; 180:1228-9; author reply 1229. [PMID: 19506284 PMCID: PMC2691442 DOI: 10.1503/cmaj.1090017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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95
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Allen MJ, Jaspars M. Realizing the potential of marine biotechnology: CHALLENGES & OPPORTUNITIES. Ind Biotechnol (New Rochelle N Y) 2009. [DOI: 10.1089/ind.2009.5.077] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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96
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Monier A, Pagarete A, de Vargas C, Allen MJ, Read B, Claverie JM, Ogata H. Horizontal gene transfer of an entire metabolic pathway between a eukaryotic alga and its DNA virus. Genome Res 2009; 19:1441-9. [PMID: 19451591 DOI: 10.1101/gr.091686.109] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Interactions between viruses and phytoplankton, the main primary producers in the oceans, affect global biogeochemical cycles and climate. Recent studies are increasingly revealing possible cases of gene transfers between cyanobacteria and phages, which might have played significant roles in the evolution of cyanobacteria/phage systems. However, little has been documented about the occurrence of horizontal gene transfer in eukaryotic phytoplankton/virus systems. Here we report phylogenetic evidence for the transfer of seven genes involved in the sphingolipid biosynthesis pathway between the cosmopolitan eukaryotic microalga Emiliania huxleyi and its large DNA virus EhV. PCR assays indicate that these genes are prevalent in E. huxleyi and EhV strains isolated from different geographic locations. Patterns of protein and gene sequence conservation support that these genes are functional in both E. huxleyi and EhV. This is the first clear case of horizontal gene transfer of multiple functionally linked enzymes in a eukaryotic phytoplankton-virus system. We examine arguments for the possible direction of the gene transfer. The virus-to-host direction suggests the existence of ancient viruses that controlled the complex metabolic pathway in order to infect primitive eukaryotic cells. In contrast, the host-to-virus direction suggests that the serial acquisition of genes involved in the same metabolic pathway might have been a strategy for the ancestor of EhVs to stay ahead of their closest relatives in the great evolutionary race for survival.
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Shen HM, Poirier MG, Allen MJ, North J, Lal R, Widom J, Storb U. The activation-induced cytidine deaminase (AID) efficiently targets DNA in nucleosomes but only during transcription. J Biophys Biochem Cytol 2009. [DOI: 10.1083/jcb1853oia5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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98
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Shen HM, Poirier MG, Allen MJ, North J, Lal R, Widom J, Storb U. The activation-induced cytidine deaminase (AID) efficiently targets DNA in nucleosomes but only during transcription. ACTA ACUST UNITED AC 2009; 206:1057-71. [PMID: 19380635 PMCID: PMC2715043 DOI: 10.1084/jem.20082678] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The activation-induced cytidine deaminase (AID) initiates somatic hypermutation, class-switch recombination, and gene conversion of immunoglobulin genes. In vitro, AID has been shown to target single-stranded DNA, relaxed double-stranded DNA, when transcribed, or supercoiled DNA. To simulate the in vivo situation more closely, we have introduced two copies of a nucleosome positioning sequence, MP2, into a supercoiled AID target plasmid to determine where around the positioned nucleosomes (in the vicinity of an ampicillin resistance gene) cytidine deaminations occur in the absence or presence of transcription. We found that without transcription nucleosomes prevented cytidine deamination by AID. However, with transcription AID readily accessed DNA in nucleosomes on both DNA strands. The experiments also showed that AID targeting any DNA molecule was the limiting step, and they support the conclusion that once targeted to DNA, AID acts processively in naked DNA and DNA organized within transcribed nucleosomes.
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Wilson WH, Van Etten JL, Allen MJ. The Phycodnaviridae: the story of how tiny giants rule the world. Curr Top Microbiol Immunol 2009; 328:1-42. [PMID: 19216434 DOI: 10.1007/978-3-540-68618-7_1] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The family Phycodnaviridae encompasses a diverse and rapidly expanding collection of large icosahedral, dsDNA viruses that infect algae. These lytic and lysogenic viruses have genomes ranging from 160 to 560 kb. The family consists of six genera based initially on host range and supported by sequence comparisons. The family is monophyletic with branches for each genus, but the phycodnaviruses have evolutionary roots that connect them with several other families of large DNA viruses, referred to as the nucleocytoplasmic large DNA viruses (NCLDV). The phycodnaviruses have diverse genome structures, some with large regions of noncoding sequence and others with regions of ssDNA. The genomes of members in three genera in the Phycodnaviridae have been sequenced. The genome analyses have revealed more than 1000 unique genes, with only 14 homologous genes in common among the three genera of phycodnaviruses sequenced to date. Thus, their gene diversity far exceeds the number of so-called core genes. Not much is known about the replication of these viruses, but the consequences of these infections on phytoplankton have global affects, including influencing geochemical cycling and weather patterns.
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Field D, Garrity G, Gray T, Morrison N, Selengut J, Sterk P, Tatusova T, Thomson N, Allen MJ, Angiuoli SV, Ashburner M, Axelrod N, Baldauf S, Ballard S, Boore J, Cochrane G, Cole J, Dawyndt P, De Vos P, DePamphilis C, Edwards R, Faruque N, Feldman R, Gilbert J, Gilna P, Glöckner FO, Goldstein P, Guralnick R, Haft D, Hancock D, Hermjakob H, Hertz-Fowler C, Hugenholtz P, Joint I, Kagan L, Kane M, Kennedy J, Kowalchuk G, Kottmann R, Kolker E, Kravitz S, Kyrpides N, Leebens-Mack J, Lewis SE, Li K, Lister AL, Lord P, Maltsev N, Markowitz V, Martiny J, Methe B, Mizrachi I, Moxon R, Nelson K, Parkhill J, Proctor L, White O, Sansone SA, Spiers A, Stevens R, Swift P, Taylor C, Tateno Y, Tett A, Turner S, Ussery D, Vaughan B, Ward N, Whetzel T, San Gil I, Wilson G, Wipat A. The minimum information about a genome sequence (MIGS) specification. Nat Biotechnol 2008; 26:541-7. [PMID: 18464787 PMCID: PMC2409278 DOI: 10.1038/nbt1360] [Citation(s) in RCA: 969] [Impact Index Per Article: 60.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
With the quantity of genomic data increasing at an exponential rate, it is imperative that these data be captured electronically, in a standard format. Standardization activities must proceed within the auspices of open-access and international working bodies. To tackle the issues surrounding the development of better descriptions of genomic investigations, we have formed the Genomic Standards Consortium (GSC). Here, we introduce the minimum information about a genome sequence (MIGS) specification with the intent of promoting participation in its development and discussing the resources that will be required to develop improved mechanisms of metadata capture and exchange. As part of its wider goals, the GSC also supports improving the 'transparency' of the information contained in existing genomic databases.
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