Plener L.,French National Institute for Agricultural Research |
Manfredi P.,French National Institute for Agricultural Research |
Valls M.,Facultat de Biologia |
Genin S.,French National Institute for Agricultural Research
Journal of Bacteriology | Year: 2010
The ability of Ralstonia solanacearum to cause disease in plants depends on its type III secretion system (T3SS). The expression of the T3SS and its effector substrates is coordinately controlled by a regulatory cascade, at the bottom of which is HrpB. Transcription of the hrpB gene is activated by a plant-responsive regulator named HrpG, which is a master regulator of a wide array of pathogenicity functions in R. solanacearum. We have identified in the genome of strain GMI1000 a close paralog of hrpG (83% overall similarity at the protein level) that we have named prhG. Despite this high similarity, the expression pattern of prhG is remarkably different from that of hrpG: prhG expression is activated after growth of bacteria in minimal medium but not in the presence of host cells, while hrpG expression is specifically induced in response to plant cell signals. We provide genetic evidence that prhG is a transcriptional regulator that, like hrpG, controls the expression of hrpB and the hrpB-regulated genes under minimal medium conditions. However, the regulatory functions of prhG and hrpG are distinct: prhG has no influence on hrpB expression when the bacteria are in the presence of plant cells, and transcriptomic profiling analysis of a prhG mutant revealed that the PrhG and HrpG regulons have only one pathogenicity target in common, hrpB. Functional complementation experiments indicated that PrhG and HrpG are individually sufficient to activate hrpB expression in minimal medium. Rather surprisingly, a prhG disruption mutant had little impact on pathogenicity, which may indicate that prhG has a minor role in the activation of T3SS genes when R. solanacearum grows parasitically inside the plant. The cross talk between pathogenicity regulatory proteins and environmental signals described here denotes that an intricate network is at the basis of the bacterial disease program. Copyright © 2010, American Society for Microbiology. All Rights Reserved.
Garanto A.,Facultat de Biologia |
Garanto A.,University of Barcelona |
Garanto A.,Institute Salud Carlos III |
Vicente-Tejedor J.,University of Alcalá |
And 11 more authors.
Biochimica et Biophysica Acta - Molecular Basis of Disease | Year: 2012
In order to approach the function of the retinal dystrophy . CERKL gene we generated a novel knockout mouse model by cre-mediated targeted deletion of the . Cerkl first exon and proximal promoter. The excised genomic region (2.3. kb) encompassed the first . Cerkl exon, upstream sequences including the proximal promoter and the initial segment of the first intron. The . Cerkl-/- mice were viable and fertile. The targeted . Cerkl deletion resulted in a knockdown more than a knockout model, given that alternative promoters (unreported at that time) directed basal expression of . Cerkl (35%). . In situ hybridizations and immunohistochemistry showed that this remnant expression was moderate in the photoreceptors and weak in the ganglion and inner cell layers. Morphological characterization of the . Cerkl-/- retinas did not show any gross structural changes, even at 12. months of age. However, some clear and consistent signals of gliosis and retinal stress were detected by the statistically significant increase of i) the glial fibrillary antigen protein (GFAP) expression, and ii) apoptosis, as detected by TUNEL. Remarkably, consistent non-progressive perturbation (from birth up to 12. months of age) of ganglion cells was supported by the decrease of the Brn3a marker expression as well as the reduced oscillatory potentials in the electroretinographic recordings. In conclusion, the . Cerkl-/- knockdown shows a mild retinal phenotype, with increased levels of cellular stress and apoptosis indicators, and clear signs of functional alteration at the ganglion cell layer, but no detectable morphological changes. © 2012 Elsevier B.V..
Pomares E.,Facultat de Biologia |
Pomares E.,University of Barcelona |
Pomares E.,Institute Salud Carlos III |
Bures-Jelstrup A.,Institute Microcirugia Ocular |
And 8 more authors.
Investigative Ophthalmology and Visual Science | Year: 2012
PURPOSE. To characterize the molecular basis of two novel BEST1 mutations causing autosomal recessive bestrophinopathy (ARB). Strong evidence argues in favor of the dominant negative effects of most autosomal dominantly inherited mutations, whereas there is only weak support for the molecular basis of the ARB phenotype. METHODS. Patients underwent ophthalmic examination, color and autofluorescence fundus imaging, optical coherence tomography (OCT), electrooculogram, and full-field electroretinogram (ERG). BEST1 was directly screened for mutations in two ARB unrelated patients. The pathogenicity of the new BEST1 variants was assessed in silico and in vivo. RESULTS. Two unrelated patients with diagnoses of ARB showed retinal pigment epithelial disturbances and abnormal ERGs. Each patient was homozygous for a novel BEST1 mutation, c.521_522del and c.1100+1G≥A. A carrier sibling (WT/c.521_522del) was unaffected. Both mutations generate a frameshift and a premature stop codon that, if translated, would seriously compromise bestrophin- 1 function. However, the in vivo quantitative RT-PCR assays showed that most of the mutated transcripts were eliminated before translation because the mRNA-BEST1 levels were dramatically diminished the controls. CONCLUSIONS. In truncating BEST1 mutations, the null phenotype associated with ARB is attributed to a substantial decrease of BEST1 expression promoted by the nonsense-mediated decay (NMD) surveillance mechanism. Moreover, the severity of the phenotype increases with the preserved amount of altered transcript, suggesting that the clinical outcome reflects the combined null and dominant negative effects of the two mutations over the patient's genetic background. © 2012 The Association for Research in Vision and Ophthalmology, Inc.
Sinev A.Y.,Moscow State University |
Alonso M.,Facultat de Biologia |
Miracle M.R.,University of Valencia |
Sahuquillo M.,University of Valencia
Zootaxa | Year: 2012
A study of several populations of the West Palaearctic endemic Alona azorica Frenzel & Alonso, 1988 reveals the existence of a sibling-species. Alona azorica s. str. is confined to the Azores and the Atlantic part of West Iberia; Alona anastasia sp. nov. inhabits temporary ponds in Mediterranean Iberia and other West Mediterranean regions. It differs by size, by the morphology of the head shield and head pores, and by the shape of the male postabdomen. Both species belong to the pulchella-group of Alona s. lato. Alona anastasia sp. nov. population dynamics and seasonal variation in body size in the province of Valencia (Spain) are also studied. Copyright © 2012 Magnolia Press.
Alonso M.,Facultat de Biologia |
Ventura M.,CSIC - Center for Advanced Studies of Blanes |
Ventura M.,University of Barcelona
Zootaxa | Year: 2013
A new species of Phallocryptus Biraben 1951 (Branchiopoda, Anostraca) from Mongolia is described. Phallocryptus tse-rensodnomi sp. nov. is close to P. spinosa (Milne-Edwards 1840), but both morphological and molecular analyses (Cyto-chrome Oxidase I, COI) indicate that they represent separate species. Most relevant differential features of the new species include: (1) frontal appendage provided with small ventral conical outgrowths; (2) second antennamere evenly curved, sickle-shaped; (3) distal fleshy process on labrum evenly curved forwards and tapering; (4) short stout acute spine-like projections present at each side of basal portion of gonopods; (5) female second antennae shorter and wider than in P. spinosa, tapering. Based on morphological comparisons the new species appears to be a Mongolian endemic, although some genotypes of presumed P. spinosa from Africa are similar to the new species, suggesting P. tserensodnomi might have a wider distribution. Copyright © 2013 Magnolia Press.
Cotn J.,Facultat de Biologia |
Garca-Tarrason M.,Facultat de Biologia |
Jover L.,University of Barcelona |
Sanpera C.,Facultat de Biologia
Ecotoxicology | Year: 2012
The Flix reservoir, in the low course of the Ebro River, contains thousands of tons of polluted sediments, accumulated from the activities of a chemical factory. An ongoing project is working toward removing these pollutants. Piscivore birds like the purple heron (Ardea purpurea) may be useful bioindicators, so eggs and nestling feathers were sampled during the 2006-2008 breeding seasons at three localities: a reference site situated upstream and two potentially affected by the toxic muds; one at the focal area and one at a distal area, the Ebro Delta. The samples were analyzed for isotopic signatures of 15N and 13C and concentrations of heavy metals and selenium. Baseline nitrogen signatures were higher in riverine sites than in the delta. Nitrogen together with carbon signatures adequately discriminated riverine and deltaic ecosystems. Mercury levels are highly influenced by the polluted sediments at Flix and pose potential risks for the birds, as they are among the highest ever recorded in heron species. Selenium and copper concentrations probably derive from other sources. Except for mercury, heavy metals and selenium levels were below toxic levels. Purple heron eggs and nestling feathers have demonstrated their usefulness as bioindicators for pollution in the river biota; feathers in particular show pollutant impacts on a strict local basis. A long series of study years is necessary in dynamic ecosystems such as this, so continued monitoring of the heron population at Flix is advisable to trace the effects of the toxic muds, particularly during their removal, because of the high levels of mercury detected. © Springer Science+Business Media, LLC 2012.
Munoz Z.,Facultat de Biologia |
Moret A.,Facultat de Biologia
Pest Management Science | Year: 2010
Background: The antifungal properties of chitosan and acibenzolar-S-methyl were evaluated to assess their potential for protecting grapes against Botrytis cinerea Pers.: Fr. isolated from Vitis vinifera L. The objectives were to determine the effects of these compounds on the in vitro development of B. cinerea and to assess their effectiveness at controlling grey mould on grapes stored at different temperatures. Results: Both agents significantly inhibited the radial growth of this fungus species. The EC50 was 1.77 mg mL-1 for chitosan and 3.44 mg mL-1 for acibenzolar-S-methyl. In addition, single grapes treated with aqueous solutions of chitosan (1.0 and 2.5 mg mL-1) and acibenzolar-S-methyl (1.0 and 3.0 mg mL-1) were inoculated with B. cinerea and incubated at both 4 and 24 C. After 4 days at 24 °C, all the concentrations of chitosan and acibenzolar-S-methyl significantly reduced B. cinerea growth. However, at 4 °C, significant differences were only observed between chitosan at 2.5 mg mL-1 and acibenzolar-S-methyl at both 1.0 and 3.0 mg mL-1 and the corresponding controls. After 3 days at 24°C, the greatest reduction in lesion size was obtained in grapes pretreated with acibenzolar-S-methyl at 3.0 mg mL-1. Only the highest doses of these products significantly reduced the lesion diameters when grapes were stored for 3 days at 4°C. Conclusions: Chitosan and acibenzolar-S-methyl could directly inhibit the growth of Botrytis cinerea in vitro and confer resistance on grapes against grey mould. Pretreatment with these compounds could be an alternative to traditional fungicides in post-harvest disease control in grapes. © 2010 Society of Chemical Industry.
Kotov A.A.,RAS Severtsov Institute of Ecology |
Alonso M.,Facultat de Biologia
Zootaxa | Year: 2010
We describe two new species of Leydigia Kurz, 1875 (Chydoridae, Cladocera) from Spain. L. (Neoleydigia) iberica sp. nov. has a series of traits rarely observed in well-studied species of the subgenus L. (Neoleydigia), and never in this combination: (1) PP distance large; (2) numerous, low hillocks on preanal margin of postabdomen; (3) numerous setae in lateral fascicles on postabdomen, plus distalmost and next setae subequal in size; (4) sensory seta shifted to distal end of antenna I, but not so markedly as in L. microps; (5) fully setulated basal segment of distalmost scraper on limb III; (6) 5 setae on exopodite III. L (N.) korovchinskyi sp. nov. has seven setae on limb III exopodite, characteristic for only two species of the subgenus L. (Neoleydigia) Kotov, 2009, namely L. (N.) propinqua and L. (N.) microps, but the former differs from both latter taxa in: (1) absence of a "coarse" striation; (2) rounded apex of labral keel and (3) longer setae 3-4 of exopodite III. At this moment, each species was found in a single locality. Both species are rare and seem endemic of Iberian Peninsula (but may be found in some surrounded Mediterranean territories); they could be regarded as relicts sensu Korovchinsky (2006). © 2010 Magnolia Press.
PubMed | Facultat de Biologia
Type: | Journal: Zootaxa | Year: 2015
A new species of Phallocryptus Biraben 1951 (Branchiopoda, Anostraca) from Mongolia is described. Phallocryptus tserensodnomi sp. nov. is close to P. spinosa (Milne-Edwards 1840), but both morphological and molecular analyses (Cytochrome Oxidase I, COI) indicate that they represent separate species. Most relevant differential features of the new species include: (1) frontal appendage provided with small ventral conical outgrowths; (2) second antennamere evenly curved, sickle-shaped; (3) distal fleshy process on labrum evenly curved forwards and tapering; (4) short stout acute spine-like projections present at each side of basal portion of gonopods; (5) female second antennae shorter and wider than in P. spinosa, tapering. Based on morphological comparisons the new species appears to be a Mongolian endemic, although some genotypes of presumed P spinosa from Africa are similar to the new species, suggesting P. tserensodnomi might have a wider distribution.
PubMed | Facultat de Biologia
Type: | Journal: ZooKeys | Year: 2015
The ten species of the genus Trypogeus Lacordaire are revised. Trypogeusapicalis Fisher, 1936, is proposed as a new synonym of Trypogeusjavanicus Aurivillius, 1925. A neotype for Trypogeussericeus (Gressitt, 1951) and lectotypes for Toxotusfuscus Nonfried, 1894 and Trypogeusjavanicus are designated. Trypogeusfuscus auct. nec Nonfried is a misidentification of Philusophthalmicus Pascoe. All the species are described and keys are given for distinguishing the species. Photographs of the types of all the Trypogeus species are published for the first time.