West Nile virus outbreak in captive and wild raptors,Czech Republic, 2018

West Nile virus lineage 2 (WNV‐2) was detected in the brain of 17 goshawks (Accipiter gentilis) that succumbed to neuroinvasive disease in the Czech Republic during 2018: twelve birds were captive and five wild. Furthermore, two wild sparrowhawks (Accipiter nisus) and three other captive birds of prey (golden eagle Aquila chrysaetos, hybrid saker falcon Falco cherrug × F. rusticolus and Harris's hawk Parabuteo unicinctus) also died due to WNV encephalitis. The 2018 outbreak in Czech raptors clearly reflects a new epidemiological situation and indicates an increasing risk of both raptor and human infection with WNV‐2 in the country.     

Modelling growth and body composition in fish nutrition: where have we been and where are we going?

Mathematical models in fish nutrition have proven indispensable in estimating growth and feed requirements. Nowadays, reducing the environmental footprint and improving product quality of fish culture operations are of increasing interest. This review starts by examining simple models applied to describe/predict fish growth profiles and progresses towards more comprehensive concepts based on bioenergetics and nutrient metabolism. Simple growth models often lack biological interpretation and overlook fundamental properties of fish (e.g. ectothermy, indeterminate growth). In addition, these models disregard possible variations in growth trajectory across life stages. Bioenergetic models have served to predict not only fish growth but also feed requirements and waste outputs from fish culture operations. However, bioenergetics is a concept based on energy-yielding equivalence of chemicals and has significant limitations. Nutrient-based models have been introduced into the fish nutrition literature over the last two decades and stand as a more biologically sound alternative to bioenergetic models. More mechanistic models are required to expand current understanding about growth targets and nutrient utilization for biomass gain. Finally, existing models need to be adapted further to address effectively concerns regarding sustainability, product quality and body traits.     

Structural development of Pacific red snapper Lutjanus peru from hatching to the onset of first feeding

Successful rearing of larval fish requires culture conditions and feeding strategies matching the ontogenetic status of larvae. This study describes the external morphology and development of organs and structures involved in the feeding process (i.e. sensorial organs, mouthparts and digestive system) from hatching until first feeding in Pacific red snapper. Hatching occurred 26 h after fertilization at 26°C and total length (TL) was 2.45 ± 0.08 mm. The larvae showed an undifferentiated eye and digestive tract. At 48 hah, TL was 3.31 ± 0.12 mm. Yolk and oil globule were still present. The mouth was still closed, but the Meckel's, quadrate, hyoid and hyomandibular cartilages were present. The retina was formed by 5 layers, and a thin layer of pigment epithelium was observed in the outer nuclear layer (ONL). At 70 hah, TL was 3.44 ± 0.22 mm. A remnant of oil globule was still present. The mouth and anus were open. At 93 hah, the number of cones in the ONL of the retina have increased and there was more pigment in the pigment epithelial layer. A joint between Meckel's and the quadrate cartilage and also a joint between the hyomandibular cartilage and the skull were present. The presence of live feed was detected in the digestive tract of these larvae. Based on these observations, the Pacific red snapper larvae is functional to start ingesting live feed between the 3rd and 4th day after hatching.     

Rapid differentiation of Ophiostoma ulmi and Ophiostoma novo‐ulmi isolates by matrix‐assisted‐laser‐desorption/ionization time‐of‐flight/time‐of‐flight mass spectrometry

The intact yeast phase spores of Ophiostoma ulmi and O. novo‐ulmi isolates were analysed by matrix‐assisted‐laser‐desorption/ionization time‐of‐flight/time‐of‐flight mass spectrometry. The results clearly showed that isolates of O. ulmi and O. novo‐ulmi have different mass peak profiles. The specific mass in m/z may vary slightly. One of the peaks from m/z 7623 to 7630 dominated (in high intensity) mass spectra for all isolates of O. novo‐ulmi tested in this study. This specific peak is believed to be CU (cerato‐ulmi) protein. However, no specific m/z peak can be found to distinguish between the isolates of ssp. novo‐ulmi and ssp. americana. On the contrary, all isolates of O. ulmi tested possessed one of a dominate peak at m/z 7337 to 7342, but none around m/z 7626 as shown in O. novo‐ulmi isolates.     

Signatures of adaptation to obligate biotrophy in the Hyaloperonospora arabidopsidis genome

Many oomycete and fungal plant pathogens are obligate biotrophs, which extract nutrients only from living plant tissue and cannot grow apart from their hosts. Although these pathogens cause substantial crop losses, little is known about the molecular basis or evolution of obligate biotrophy. Here, we report the genome sequence of the oomycete Hyaloperonospora arabidopsidis (Hpa), an obligate biotroph and natural pathogen of Arabidopsis thaliana. In comparison with genomes of related, hemibiotrophic Phytophthora species, the Hpa genome exhibits dramatic reductions in genes encoding (i) RXLR effectors and other secreted pathogenicity proteins, (ii) enzymes for assimilation of inorganic nitrogen and sulfur, and (iii) proteins associated with zoospore formation and motility. These attributes comprise a genomic signature of evolution toward obligate biotrophy.     

Gene flow among different teosinte taxa and into the domesticated maize gene pool

Maize (Zea mays L. ssp. mays) was domesticated from one wild species ancestor, the Balsas teosinte (Zea mays ssp. parviglumis) about 9000 years ago. Higher levels of gene diversity are found in teosinte taxa compared to maize, following domestication and selection bottlenecks. Diversity in maize can be increased via gene flow from teosinte, which has certainly occurred from various taxa, but the rate of flow from different teosinte taxa and the final impact on maize evolution has been difficult to measure. One hundred populations from six Zea taxa, both domesticated (maize) and wild (teosinte), including domesticated landraces from Asia, Africa, and the Americas, were genotyped with 17 SSR markers using 15 individuals per population. Overall levels of diversity were high, and populations could be distinguished based on markers. Relationships between populations followed most published reports, or can now help resolve previously conflicting reports. Gene flow into maize from different teosinte groups, and gene flow between different teosintes, was estimated. Evidence for contributions from the Balsas teosintes and from Chalco teosintes (Z. mays ssp. mexicana) to the maize gene pool was found, as well as from Chalco into ssp. mexicana race ??Durango?? and Z. mays ssp. huehuetenengensis. These contributions are almost certainly the result of post-domestication (and ongoing) exchanges. This information must give more impetus to in situ conservation of teosinte species, and use of these teosintes to continue to direct the evolution of maize, especially in response to new diseases, insect pests, and other biotic and abiotic stresses.     

Chemical resistance of Pinus densiflora to Fomes annosus

One compound isolated from the stem wood of Pinus densiflora Sieb. Zucc. is responsible for its resistance to Fomes annosus (Fr.) Cke. From thin layer chromatography and microanalytical evidence, the inhibitory compound is nitrogenous and may be an alkaloid.     

Development of a polyvalent RT‐PCR detection assay covering the genetic diversity of Cherry capillovirus A

The variability of Cherry capillovirus A (CVA) was analysed using a short, 275‐bp region of the viral RNA‐dependent RNA polymerase gene amplified by a polyvalent RT‐PCR assay. As for other members of the family Betaflexiviridae, CVA appears to show significant diversity, with an average pairwise nucleotide divergence of 9·4% between isolates in the analysed region. Phylogenetic analyses provide evidence for the existence of at least five clusters of CVA isolates, one of which is associated with noncherry hosts of the virus, providing evidence that transmission of CVA isolates between cherry and noncherry hosts is probably rare. Comparison of existing detection techniques using a panel of CVA isolates representative of the various phylogenetic groups indicated that dot‐blot hybridization assays show high polyvalence but may lack the sensitivity to detect CVA in some samples. On the other hand, available detection primers failed to amplify a wide range of CVA isolates. Partial genome sequencing of two divergent isolates allowed the identification of conserved genomic regions and the design of new primer pairs with improved polyvalence. These new primer pairs were used to develop PCR assays allowing the reliable detection of CVA isolates belonging to all phylogenetic clusters.     

Post-operative analgesic effects,after orthopaedic surgery in the dog,of loco-regional ropivacaine and bupivacaine blockade using the nerve locator technique: 159 cases

Veterinary Research Communications -