Activation of Drosophila Toll during fungal infection by a blood serine protease

Drosophila host defense to fungal and Gram-positive bacterial infection is mediated by the Spaetzle/Toll/cactus gene cassette. It has been proposed that Toll does not function as a pattern recognition receptor per se but is activated through a cleaved form of the cytokine Spaetzle. The upstream events linking infection to the cleavage of Spaetzle have long remained elusive. Here we report the identification of a central component of the fungal activation of Toll. We show that ethylmethane sulfonate-induced mutations in the persephone gene, which encodes a previously unknown serine protease, block induction of the Toll pathway by fungi and resistance to this type of infection.     

Pharmacokinetics of meloxicam in plasma and urine of horses

OBJECTIVE: To determine pharmacokinetic parameters for meloxicam, a nonsteroidal anti-inflammatory drug, in horses. ANIMALS: 8 healthy horses. PROCEDURE: In the first phase of the study, horses were administered meloxicam once in accordance with a 2 x 2 crossover design (IV or PO drug administration; horses fed or not fed). The second phase used a multiple-dose regimen (daily oral administration of meloxicam for 14 days), with meloxicam administered at the recommended dosage (0.6 mg/kg). Plasma and urine concentrations of meloxicam were measured by use of validated methods with a limit of quantification of 10 ng/mL for plasma and 20 ng/mL for urine. RESULTS: Plasma clearance was low (mean +/- SD; 34 +/- 0.5 mL/kg/h), steady-state volume of distribution was limited (0.12 +/- 0.018 L/kg), and terminal half-life was 8.54 +/- 3.02 hours. After oral administration, bioavailability was nearly total regardless of feeding status (98 +/- 12% in fed horses and 85 +/- 19% in nonfed horses). During once-daily administration for 14 days, we did not detect drug accumulation in the plasma. Meloxicam was eliminated via the urine with a urine-to-plasma concentration that ranged from 13 to 18. Concentrations were detected for a relatively short period (3 days) after administration of the final daily dose. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study support once-daily administration of meloxicam regardless of the feeding status of a horse and suggest a period of at least 3 days before urine concentrations of meloxicam reach concentrations that could be used in drug control programs.     

Is it a hindrance for an invasive aquatic species to spread across scattered habitat patches?

1. Despite their importance for aquatic biodiversity, ponds are among the most vulnerable freshwater habitats. Owing to their isolation in terrestrial environments, ponds are expected to be relatively well protected from biological invasions, but this depends on many factors. 2. The purpose of this study was to examine the influence of a range of variables (water quality, habitat, and landscape attributes) on the colonization of discrete ponds by a widespread aquatic invader, the red swamp crayfish Procambarus clarkii, which can disperse overland. 3. Investigations were conducted in two networks of ponds, each located in close proximity to a large invaded marsh. The two marshes under study differed in the length of time since the crayfish were introduced. 4. The proportions of colonized ponds and crayfish abundances were moderate in both networks, but higher in the network that had been invaded first. In both networks the distance to the marsh was the main predictor of pond colonization, considering similar energy costs to cross aquatic and terrestrial habitats for the recently invaded network, but assuming that dispersal was 25 times costlier across the terrestrial matrix than via streams for the earlier invaded network. Pond characteristics had no influence on crayfish occurrence in either network. Furthermore, predictions of pond invasion were lower for the recently invaded network. 5. The importance of the distance to the marsh indicates that natural dispersal was the main process of pond colonization by crayfish. Findings also suggested that overland dispersal was rare and costly. By contrast, streams were probably significant in facilitating crayfish dispersal. Differences between the two networks might arise from an invasion process still in progress in the recently invaded network. 6. From a management viewpoint, local actions are encouraged to prevent the spread of crayfish via streams. In addition, broader‐scale actions to mitigate other human disturbances would improve the outlook for pond biodiversity.     

Nickel seminal concentrations in various animals and correlation to spermatozoa quality

In this study, the concentration of nickel in stallion, bull, ram, boar and fox semen, and its relation with spermatozoa quality was analyzed. The concentration of nickel in semen was 0.20 mg kg(-1) in stallion, 0.12 mg kg(-1) in bull, 0.31 mg kg(-1) in ram, 0.06 mg kg(-1) in boar and 0.36 mg kg(-1) in fox. Seminal nickel concentration was significantly higher (P < 0.05) in foxes than that in bulls and significantly higher (P < 0.01) in rams and foxes in comparison with boars. Evaluation of total pathological spermatozoa revealed the highest number in stallions followed by rams, bulls, boars and foxes. In bull, ram and boar semen, separated flagellum, flagellum torso and knob-twisted flagellum were predominant. Knob-twisted flagellum, separated flagellum and flagellum torso were found in increased number in stallion semen and broken flagellum in fox semen. Correlation analysis in bulls indicated a high positive correlation between seminal nickel and separated flagellum (r = 0.76) and medium positive correlation between nickel and flagellum torso (r = 0.62), and in rams a high positive correlation between nickel and separated flagellum (r = 0.77). Medium positive correlation was found between nickel and separated flagellum (r = 0.43) and between nickel and other pathological spermatozoa (r = 0.45) in boars.     

Dietary indispensable amino acids profile affects protein utilization and growth of Senegalese sole larvae

In diet formulation for fish, it is critical to assure that all the indispensable amino acids (IAA) are available in the right quantities and ratios. This will allow minimizing dietary AA imbalances that will result in unavoidable AA losses for energy dissipation rather than for protein synthesis and growth. The supplementation with crystalline amino acids (CAA) is a possible solution to correct the dietary amino acid (AA) profile that has shown positive results for larvae of some fish species. This study tested the effect of supplementing a practical microdiet with encapsulated CAA as to balance the dietary IAA profile and to improve the capacity of Senegalese sole larvae to utilize AA and maximize growth potential. Larvae were reared at 19 °C under a co-feeding regime from mouth opening. Two microdiets were formulated and processed as to have as much as possible the same ingredients and proximate composition. The control diet (CTRL) formulation was based on commonly used protein sources. A balanced diet (BAL) was formulated as to meet the ideal IAA profile defined for Senegalese sole: the dietary AA profile was corrected by replacing 4 % of encapsulated protein hydrolysate by CAA. The in vivo method of controlled tube-feeding was used to assess the effect on the larvae capacity to utilize protein, during key developmental stages. Growth was monitored until 51 DAH. The supplementation of microdiets with CAA in order to balance the dietary AA had a positive short-term effect on the Senegalese sole larvae capacity to retain protein. However, that did not translate into increased growth. On the contrary, larvae fed a more imbalanced (CTRL group) diet attained a better performance. Further studies are needed to ascertain whether this was due to an effect on the voluntary feed intake as a compensatory response to the dietary IAA imbalance in the CTRL diet or due to the higher content of tryptophan in the BAL diet.     

Strong differentiation within Diplocarpon rosae strains based on microsatellite markers and greenhouse-based inoculation protocol on Rosa

The haploid ascomycete Diplocarpon rosae is the causal agent of black spot disease on roses, a widespread and devastating disease in the outdoor landscape. In this study, we established a Eurasian collection of 77 monoconidial strains of D. rosae: 50 strains collected on cultivated roses in Europe and Asia, and 27 strains on wild roses in Kazakhstan. To provide tools to describe its biology and to study its genetic diversity, we sequenced two strains of D. rosae using Illumina paired-end technology. The genome sizes of these two strains were estimated at 31.1 and 35.2 Mb, which are two times smaller than the genome size of the unique strain previously published. A BUSCO analysis confirmed a genome duplication of the strain previously sequenced and partial gene duplication of strains analysed in this study. Using the two genome sequences, 27 polymorphic microsatellite markers were identified. Polymorphism analysis of the 77 strains revealed a strong genetic differentiation between strains from cultivated and wild roses, and a lower diversity within the fungal population from cultivated roses compared to the population from wild roses. Pathogenicity of 10 strains was evaluated on 9 rose cultivars inoculated in the greenhouse. Disease scoring allowed the classification of strains into three groups and the characterization of resistance of rose cultivars. Good correlation observed between resistance scoring in greenhouse conditions and in the field indicates that pathogenicity assays in controlled conditions could be very useful in the near future to rapidly characterize the resistance of new rose varieties to black spot disease.     

Identification of rumen microbial biomarkers linked to methane emission in Holstein dairy cows

Mitigation of greenhouse gas emissions is relevant for reducing the environmental impact of ruminant production. In this study, the rumen microbiome from Holstein cows was characterized through a combination of 16S rRNA gene and shotgun metagenomic sequencing. Methane production (CH₄) and dry matter intake (DMI) were individually measured over 4–6 weeks to calculate the CH₄ yield (CH₄y = CH₄/DMI) per cow. We implemented a combination of clustering, multivariate and mixed model analyses to identify a set of operational taxonomic unit (OTU) jointly associated with CH₄y and the structure of ruminal microbial communities. Three ruminotype clusters (R1, R2 and R3) were identified, and R2 was associated with higher CH₄y. The taxonomic composition on R2 had lower abundance of Succinivibrionaceae and Methanosphaera, and higher abundance of Ruminococcaceae, Christensenellaceae and Lachnospiraceae. Metagenomic data confirmed the lower abundance of Succinivibrionaceae and Methanosphaera in R2 and identified genera (Fibrobacter and unclassified Bacteroidales) not highlighted by metataxonomic analysis. In addition, the functional metagenomic analysis revealed that samples classified in cluster R2 were overrepresented by genes coding for KEGG modules associated with methanogenesis, including a significant relative abundance of the methyl-coenzyme M reductase enzyme. Based on the cluster assignment, we applied a sparse partial least-squares discriminant analysis at the taxonomic and functional levels. In addition, we implemented a sPLS regression model using the phenotypic variation of CH₄y. By combining these two approaches, we identified 86 discriminant bacterial OTUs, notably including families linked to CH₄ emission such as Succinivibrionaceae, Ruminococcaceae, Christensenellaceae, Lachnospiraceae and Rikenellaceae. These selected OTUs explained 24% of the CH₄y phenotypic variance, whereas the host genome contribution was ~14%. In summary, we identified rumen microbial biomarkers associated with the methane production of dairy cows; these biomarkers could be used for targeted methane-reduction selection programmes in the dairy cattle industry provided they are heritable.     

Community of vascular epiphytes on some phorophytes in the Babadjou Subdivision (Western Cameroon): Case of Bamelo

The environmental degradation of the western region of Cameroon has intensified over time and has contributed to the perturbation of the original floristic uniformity of pioneer vegetation. Epiphytes, which are very sensitive plants, have refuge mostly on phorophyte, hence permitting the evaluation of the conservation state of natural ecosystems. The present study aims to assess a floristic inventory of vascular epiphytes in the locality of Bamelo. Sampling was carried out on 100 individuals, 20 individuals for each of the five phorophyte species based on their abundance in the locality. A total of 36 species divided into eight families and 19 genera were recorded. Monocotyledons were the most abundant with 58.33% of community and represented only by the Orchidaceae family; pteridophytes and dicotyledons represent 22.22 and 19.44%, respectively. Persea amercina and Cola anomala were the most diversified phorophytes (19 species); Dacryodes edulis was the least diversified (eight). The principal component analysis revealed affinities between the epiphytic flora of Dacryodes edulis and Persea americana; Croton macrostachyus and Spathodea campanulata. At a time where the degradation of biodiversity occurs at an alarming rate, the conservation of such species becomes problematic. In view of the present results, epiphytes found refuge on fruit trees in plantations.