Assessment of cues potentially mediating host selection of Leptoglossus occidentalis on Pinus contorta

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Crown group Oxyphotobacteria postdate the rise of oxygen

The rise of oxygen ca. 2.3 billion years ago (Ga) is the most distinct environmental transition in Earth history. This event was enabled by the evolution of oxygenic photosynthesis in the ancestors of Cyanobacteria. However, long‐standing questions concern the evolutionary timing of this metabolism, with conflicting answers spanning more than one billion years. Recently, knowledge of the Cyanobacteria phylum has expanded with the discovery of non‐photosynthetic members, including a closely related sister group termed Melainabacteria, with the known oxygenic phototrophs restricted to a clade recently designated Oxyphotobacteria. By integrating genomic data from the Melainabacteria, cross‐calibrated Bayesian relaxed molecular clock analyses show that crown group Oxyphotobacteria evolved ca. 2.0 billion years ago (Ga), well after the rise of atmospheric dioxygen. We further estimate the divergence between Oxyphotobacteria and Melainabacteria ca. 2.5–2.6 Ga, which—if oxygenic photosynthesis is an evolutionary synapomorphy of the Oxyphotobacteria—marks an upper limit for the origin of oxygenic photosynthesis. Together, these results are consistent with the hypothesis that oxygenic photosynthesis evolved relatively close in time to the rise of oxygen.     

(14)C radiolabeling of proteins to monitor biodistribution of ingested proteins

The economical preparation of microgram quantities of (14)C-labeled proteins by in vacuo methylation with methyl iodide is described. The (14)C radiolabeling was achieved by the covalent attachment of [(14)C]methyl groups onto amino and imidazole groups by reaction in vacuo with [(14)C]methyl iodide. The method was tested by investigating the biodistribution of (14)C in rats that were fed (14)C-labeled human soluble cluster of differentiation 14 (CD14) protein, a receptor for bacterial lipopolysaccharide. Two other control proteins, bovine serum albumin (BSA) and casein, were also labeled with (14)C and used for comparative analysis to determine the following: (i) the efficacy and cost efficiency of the in vacuo radiolabeling procedure and (ii) the extent of incorporation of the (14)C label into the organs of orogastrically fed 10-day-old Sprague-Dawley rats. [(14)C]BSA, [(14)C]casein, and [(14)C]CD14 were individually prepared with specific radioactivities of 34,400, 18,800, and 163,000 disintegrations per minute (dpm)/microg, respectively. It was found that the accumulation of (14)C label in the organs of [(14)C]CD14-fed rats, most notably the persistence of (14)C in the stomach 480 min postgavage, was temporally and spatially distinct from [(14)C]BSA and [(14)C]casein-fed rats.     

Midazolam as an adjunctive therapy for capture myopathy in Bar-tailed Godwits (Limosa lapponica baueri) with prognostic indicators

Capture myopathy is a complication of capture and handling in many species of birds and mammals. Muscular necrosis leads to ataxia, paralysis, and pain, whereas metabolic disturbances can result in death. We conducted an opportunistic clinical trial on Bar-tailed Godwits (Limosa lapponica baueri) that developed capture myopathy after a cannon-net capture in New Zealand in October 2008. We assessed the beneficial effects of midazolam, a benzodiazepine with the effects of anxiolysis, muscle relaxation, and sedation, in the adjunctive treatment of capture myopathy. Physical and biochemical parameters were analyzed retrospectively for their potential as indicators for survival until release. Birds (n=16) were treated with subcutaneous fluid therapy, a nonsteroidal anti-inflammatory (meloxicam), gavage feeding, and sling therapy twice daily. The treatment group (n=8) was treated twice daily with intramuscular midazolam injections, 1.5 mg/kg. Surviving godwits were released over 1-9 days, with 6 of 8 treated birds (75%) surviving to release, compared with 3 of 8 controls (38%). Inability to counteract weight loss in captivity was the most significant problem for both groups. Lack of waterproofing and predation were contributing causes of death for at least two godwits after release. Birds treated with midazolam showed subjective benefits including improved tolerance of handling and sling therapy. Clinical parameters (change in body mass, packed cell volume [PCV], plasma creatine kinase [CK], aspartate aminotransferase [AST], total protein, and uric acid [UA] over time) were not statistically different between groups, although peak average values for CK, AST, and UA were lower in the treatment group. Decline in body mass (%), PCV, final plasma UA, and peak plasma CK were the most useful prognostic indicators. Midazolam shows potential as an ancillary treatment for capture myopathy in birds and is worthy of continued study and use.     

In vitro detection and quantification of botulinum neurotoxin type e activity in avian blood

Botulinum neurotoxin serotype E (BoNT/E) outbreaks in the Great Lakes region cause large annual avian mortality events, with an estimated 17,000 bird deaths reported in 2007 alone. During an outbreak investigation, blood collected from bird carcasses is tested for the presence of BoNT/E using the mouse lethality assay. While sensitive, this method is labor-intensive and low throughput and can take up to 7 days to complete. We developed a rapid and sensitive in vitro assay, the BoTest Matrix E assay, that combines immunoprecipitation with high-affinity endopeptidase activity detection by Förster resonance energy transfer (FRET) to rapidly quantify BoNT/E activity in avian blood with detection limits comparable to those of the mouse lethality assay. On the basis of the analysis of archived blood samples (n = 87) collected from bird carcasses during avian mortality investigations, BoTest Matrix E detected picomolar quantities of BoNT/E following a 2-h incubation and femtomolar quantities of BoNT/E following extended incubation (24 h) with 100% diagnostic specificity and 91% diagnostic sensitivity.     

Biodiversity of Clostridium botulinum type E associated with a large outbreak of botulism in wildlife from Lake Erie and Lake Ontario

The genetic relatedness of Clostridium botulinum type E isolates associated with an outbreak of wildlife botulism was studied using random amplification of polymorphic DNA (RAPD). Specimens were collected from November 2000 to December 2008 during a large outbreak of botulism affecting birds and fish living in and around Lake Erie and Lake Ontario. In our present study, a total of 355 wildlife samples were tested for the presence of botulinum toxin and/or organisms. Type E botulinum toxin was detected in 110 samples from birds, 12 samples from fish, and 2 samples from mammals. Sediment samples from Lake Erie were also examined for the presence of C. botulinum. Fifteen of 17 sediment samples were positive for the presence of C. botulinum type E. Eighty-one C. botulinum isolates were obtained from plants, animals, and sediments; of these isolates, 44 C. botulinum isolates produced type E toxin, as determined by mouse bioassay, while the remaining 37 isolates were not toxic for mice. All toxin-producing isolates were typed by RAPD; that analysis showed 12 different RAPD types and multiple subtypes. Our study thus demonstrates that multiple genetically distinct strains of C. botulinum were involved in the present outbreak of wildlife botulism. We found that C. botulinum type E is present in the sediments of Lake Erie and that a large range of bird and fish species is affected.     

Modeling motivational deficits in mouse models of schizophrenia: behavior analysis as a guide for neuroscience

In recent years it has become possible to develop animal models of psychiatric disease in genetically modified mice. While great strides have been made in the development of genetic and neurobiological tools with which to model psychiatric disease, elucidation of neural and molecular mechanisms thought to underlie behavioral phenotypes has been hindered by an inadequate analysis of behavior. This is unfortunate given the fact that the experimental analysis of behavior has created powerful methods for isolating and describing the functional properties of behavioral mechanisms that are capable of providing deep understanding of behavioral phenotypes. A better understanding of the biological basis of normal behavior and its disturbance in psychiatric disease will require the application of these rigorous behavior analytic tools to animal models. In this review we provide an example of a merging of genetic and behavioral methods and illustrate its utility in the analysis of a mouse model of the motivational deficits in schizophrenia. The synergy between basic behavior analysis, neuroscience, and animal models of psychiatric disease has great potential for achieving a deeper understanding of behavior and its neurobiological mechanisms as well as for leading to improvements in diagnosis and treatment in clinical settings.     

Evidence that Polymyxa species may infect Arabidopsis thaliana

Polymyxa spp. are obligate biotrophs belonging to the plasmodiophorid group, responsible for transmitting a large number of plant viruses to many crop species. Their obligate nature makes them difficult to study. Controlled environment experiments were used to investigate the potential of infection of Arabidopsis thaliana by Polymyxa spp. to provide a more tractable system. Two ecotypes of Arabidopsis, Columbia and Landsberg erecta, were grown in soils known to be infested with Polymyxa. At the end of a 2-month growth period, both ecotypes were found to harbour Polymyxa-like structures or spores. These findings were confirmed by Polymyxa-specific PCR tests and rDNA sequencing, which positively identified the presence of Polymyxa in the roots of both ecotypes of Arabidopsis. Both Polymyxa graminis and Polymyxa betae were identified. This is the first report of infection of Arabidopsis by Polymyxa spp. and shows the possibility of using this system for studies of infection biology and host-parasite interactions.