A functional screen for the type III (Hrp) secretome of the plant pathogen Pseudomonas syringae     

Guttman DS  Vinatzer BA  Sarkar SF  Ranall MV  Kettler G  Greenberg JT 《Science (New York, N.Y.)》2002,295(5560):1722-1726

Type III secreted "effector" proteins of bacterial pathogens play central roles in virulence, yet are notoriously difficult to identify. We used an in vivo genetic screen to identify 13 effectors secreted by the type III apparatus (called Hrp, for "hypersensitive response and pathogenicity") of the plant pathogen Pseudomonas syringae. Although sharing little overall homology, the amino-terminal regions of these effectors had strikingly similar amino acid compositions. This feature facilitated the bioinformatic prediction of 38 P. syringae effectors, including 15 previously unknown proteins. The secretion of two of these putative effectors was shown to be type III--dependent. Effectors showed high interstrain variation, supporting a role for some effectors in adaptation to different hosts.  相似文献   

Strong association of de novo copy number mutations with autism     

Sebat J  Lakshmi B  Malhotra D  Troge J  Lese-Martin C  Walsh T  Yamrom B  Yoon S  Krasnitz A  Kendall J  Leotta A  Pai D  Zhang R  Lee YH  Hicks J  Spence SJ  Lee AT  Puura K  Lehtimäki T  Ledbetter D  Gregersen PK  Bregman J  Sutcliffe JS  Jobanputra V  Chung W  Warburton D  King MC  Skuse D  Geschwind DH  Gilliam TC  Ye K  Wigler M 《Science (New York, N.Y.)》2007,316(5823):445-449

We tested the hypothesis that de novo copy number variation (CNV) is associated with autism spectrum disorders (ASDs). We performed comparative genomic hybridization (CGH) on the genomic DNA of patients and unaffected subjects to detect copy number variants not present in their respective parents. Candidate genomic regions were validated by higher-resolution CGH, paternity testing, cytogenetics, fluorescence in situ hybridization, and microsatellite genotyping. Confirmed de novo CNVs were significantly associated with autism (P = 0.0005). Such CNVs were identified in 12 out of 118 (10%) of patients with sporadic autism, in 2 out of 77 (3%) of patients with an affected first-degree relative, and in 2 out of 196 (1%) of controls. Most de novo CNVs were smaller than microscopic resolution. Affected genomic regions were highly heterogeneous and included mutations of single genes. These findings establish de novo germline mutation as a more significant risk factor for ASD than previously recognized.  相似文献   

Redirection of silencing targets by adenosine-to-inosine editing of miRNAs   总被引：1，自引：0，他引：1  

Kawahara Y  Zinshteyn B  Sethupathy P  Iizasa H  Hatzigeorgiou AG  Nishikura K 《Science (New York, N.Y.)》2007,315(5815):1137-1140

  相似文献   

The mosquito genome--a breakthrough for public health     

Morel CM  Touré YT  Dobrokhotov B  Oduola AM 《Science (New York, N.Y.)》2002,298(5591):79

The Anopheles gambiae genome sequence will accelerate identification of new insect vector target genes leading to improved strategies for malaria control.  相似文献   

Quantification of Aluminum-Induced Changes in Wheat Root Architecture by X-ray Microcomputed Tomography     

Boris Lazarević  Craig J. Sturrock  Milan Poljak  Sacha J. Mooney 《Communications in Soil Science and Plant Analysis》2016,47(2):263-274

Root architectural traits are of fundamental importance for plant performance, especially under unfavorable soil conditions. This study examined the effect of aluminum (Al) toxicity in different growing media (nutrient solutions and soil) on root architecture of two wheat (Triticum aestivum L.) cultivars with different Al tolerances. Seedlings were grown in acidic and limed soil and in two contrasting nutrient solutions. Root systems of soil-grown plants were scanned using x-ray microcomputed tomography (µCT) while that of nutrient solution–grown plants were assesses using WinRhizo, 3 and 5 days after planting (DAP), respectively. Aluminum caused significant reduction of all examined root traits (number of seminal roots, root length, length of the longest seminal root, root surface area, and root volume). Growth in acidic soil caused significant reduction in root length, length of the longest seminal root, and root surface area at 5 DAP. Soil-grown plants produced a larger root system compared to plants grown in nutrient solutions. Aluminum toxicity–induced differences of root traits were also found between different nutrient solutions. Beside the well-known reduction of root length, Al toxicity had a profound effect on other root architectural traits. X-ray µCT has revealed root architectural changes under specific conditions of acidic, Al-toxic soil. Differences obtained in Al-induced effects on root architecture between different nutrient solutions as well as between different growing systems emphasize the need for further study of root architecture, especially under specific conditions of Al toxicity in acidic soils.  相似文献   

Genetic Variation in Alfalfa, Sweet Clover and Fenugreek for the Activity of Symbiosis with Rhizobium meliloti     

Nicolai A.  Provorov Boris V.  Simarov 《Plant Breeding》1990,105(4):300-310

The aim of this work was to examine variation for activity of symbiosis with Rhizobium meliloti in alfalfa, sweet clover and fenugreek. Seed specimens were obtained from the collection of the All-Union Research Institute for Plant Breeding and Rhizobium strains from the All-Union Research Institute for Agricultural Microbiology, both in Leningrad. Sterile methods of vegetative culture were employed. Statistical analysis of data on inter- and intracultivar variation allow one to suppose that in alfalfa and sweet clover, nitrogenase activity and symbiotic efficiency (ability of plants to increase biomass after inoculation) are controlled by different groups of genes. The latter symbiotic property is more strictly controlled by host genotype than the former. Fenugreek appeared to be more variable in its capacity for symbiosis than alfalfa and sweet clover. Differences between genotyyes in symbiotic activity correlate with division into subspecies and are inherited in self-fertile progeny of fenugreek plants. Differences between R. meliloti strains for the efficiency of symbiosis with heterogceic natural fenugreek population are expressed to a lesser degree than with plants of more homogenic cultivar populations.  相似文献   

Habitat models and habitat connectivity analysis for butterflies and burnet moths - The example of Zygaena carniolica and Coenonympha arcania     

Birgit Binzenhöfer  Boris Schröder  Robert Biedermann 《Biological conservation》2005,126(2):247-259

In this paper, habitat models were used to predict potential habitat for endangered species, which is an important question in landscape and conservation planning. Based on logistic regression, we developed habitat distribution models for the burnet moth Zygaena carniolica and the nymphalid butterfly Coenonympha arcania in Northern Bavaria, Germany. The relation between adult occurrence and habitat parameters, including the influence of landscape context, was analyzed on 118 sites. Habitat connectivity analyses were carried out on the basis of (1) habitat suitability maps generated from these models and (2) dispersal data from mark recapture studies. Our results showed that (1) the presence of the burnet depended mainly on the presence of nectar plants and of nutrient-poor dry grasslands in direct vicinity, that of the nymphalid on larger areas of extensively used dry grasslands within 100 m vicinity in combination with small patches of higher shrubs and bushes. (2) Internal as well as external validation indicated the robustness and general applicability of the models. Transferability in time and space indicated their high potential relevance for applications in nature conservation, such as predicting possible effects of land use changes. (3) Habitat connectivity analyses revealed a high degree of habitat connectivity within the study area. Thus, we could show no effects of isolation or habitat size for both species.  相似文献   

Mercury in the Aquatic Environment of the Village of Caimito at the Mojana Region,North of Colombia   总被引：1，自引：0，他引：1  

Olivero-Verbel  Jesus  Johnson-Restrepo  Boris  Mendoza-Marín  Claudia  Paz-Martinez  Ramon  Olivero-Verbel  Rafael 《Water, air, and soil pollution》2004,159(1):409-420

During May–September 1999, several aquatic environmental samples were collected from the village of Caimito, in the San Jorge River basin area, state of Sucre (Colombia), and analyzed for total mercury (T-Hg). Mean T-Hg concentration in sediments from surrounded marshes was 0.155 ± 0.016 g Hg/g. Low Hg concentrations were found in the phytoplanktivorous fish species Prochilodus magdalenae (0.087 ± 0.01 g Hg/g), while four-fold greater concentrations were found in all the carnivorous species. In average, T-Hg concentrations for fish samples did not exceed the limit consumption level (0.5 g Hg/g). However, risk assessment based on the hazard index suggested that the consumption of 0.1 kg per day of carnivorous fish could increase the risk of mercury poisoning in local population.  相似文献   

Habitat selection by the pale-headed brush-finch (Atlapetes pallidiceps) in southern Ecuador: implications for conservation     

Steffen Oppel  H.Martin Schaefer  Boris Schröder 《Biological conservation》2004,118(1):33-40

The pale-headed brush-finch (Atlapetes pallidiceps) is threatened with extinction due to habitat loss, but very little is known about its ecological requirements. We used multiple logistic regression to study habitat selection of this species at landscape, territory, and nest site scales in order to make recommendations about effective management. Habitat selection by the sympatric stripe-headed brush-finch (Buarremon torquatus) was examined with the same methods in order to analyse interspecific resource partitioning and potential competition. The pale-headed brush-finch selected semi-open habitat types with intermediate scrub heights, and avoided forests. Nest sites depended on the presence of vines or bamboo. By contrast, the stripe-headed brush-finch chose dense habitat with low ground cover under tall vegetation and avoided semi-open habitat. The two species had overlapping territories but differed significantly in microhabitat use and the use of vegetation strata. We found no convincing evidence that the stripe-headed brush-finch displaces the pale-headed brush-finch from optimal habitat. The preservation of semi-open scrubland maintained by low-intensity grazing is suggested for future conservation of the pale-headed brush-finch.  相似文献   

Immunomodulatory effect of glucan on specific and nonspecific immunity after vaccination in puppies     

Haladová E  Mojžišová J  Smrčo P  Ondrejková A  Vojtek B  Prokeš M  Petrovová E 《Acta veterinaria Hungarica》2011,59(1):77-86

The objective of the study was to determine the immunostimulatory effect of β-(1,3/1,6)-D-glucan in puppies. The effect exerted on the efficacy of vaccination, especially against canine parvovirus and rabies infection, was studied. The application of vaccine and glucan leads to significant increases in the nonspecific immunological parameters (phagocytic ability of leukocytes, blastogenic response of lymphocytes, metabolic and chemotactic activity of polymorphonuclear cells). The level of antibodies against canine parvovirus (Ab CPV) and rabies infection reached the most statistically significant values on the 28th day after the application of vaccine and a syrup containing β-(1,3/1,6)-D-glucan (Group GV) as compared to the control group (Group V, puppies receiving only vaccine). Dogs without glucan supplementation did not produce such significant levels of antibodies. We can conclude that glucan has relevant immunostimulatory effects in dogs with altered immunity. The glucan product tested in this study (PleraSAN V, PLEURAN, Bratislava, Slovakia) could be used in the small animal clinical practice.  相似文献