Use of a weed risk assessment for the Mediterranean region of Central Italy to prevent loss of functionality and biodiversity in agro-ecosystems

The capacity to predict invasiveness of plant species is important for the conservation and management of natural habitats, especially within agro-ecosystems. Many factors increase the creation of newly available niches in this type of anthropogenic manipulated ecosystem. Consequently, the presence and establishment of invasive alien species with the potential to spread and cause harm, or constrain elements of semi-natural habitat or vegetation remnants, may increase. The invasiveness of weedy germplasm may be accelerated by the presence of cultivated species that are able to escape from fields also through crop movement or on livestock. The future use of agricultural land for widespread and intensive cultivation of biofuel crops for energy production increases the need for a pre-entry screening tool both for species that are new to the Italian cropping system and for the management of existing weedy species. This study aimed to assess the effectiveness of adapting the Australian and New Zealand Weed Risk Assessment (WRA) to the geographic, climatic and weed management context of Italy. We evaluated the performance of the adapted WRA on several alien plant species of known invasiveness in Mediterranean Central Italy. WRA score results were compared with a priori independent opinions of botanists with field experience in the evaluated region. The assessment procedure correctly identified 93% of invasive species and 75% of non-invasive species. Further evaluation was needed for 20% of the tested species and was conducted through a secondary screening. Throughout the whole process, only one (5%) of the investigated species could not be assessed. The results of the Receiver Operating Characteristic analysis, the consistency of the outcomes with those found in other WRA studies, the Chi Square testing categories and the high correlation between the a priori and WRA score corroborated the predictive accuracy of the WRA for determining invasive from non-invasive species. This confirmed the effectiveness of the screening process and an assessment was subsequently carried out on proposed biofuel species detecting some potential invaders. The WRA can thus be used to assess the introduction of new cropping systems and for weed management.     

Phage display revisited: Epitope mapping of a monoclonal antibody directed against Neisseria meningitidis adhesin A using the PROFILER technology

There is a strong need for rapid and reliable epitope mapping methods that can keep pace with the isolation of increasingly larger numbers of mAbs. We describe here the identification of a conformational epitope using Phage-based Representation OF ImmunoLigand Epitope Repertoire (PROFILER), a recently developed high-throughput method based on deep sequencing of antigen-specific lambda phage-displayed libraries. A novel bactericidal monoclonal antibody (mAb 9F11) raised against Neisseria meningitidis adhesin A (NadA), an important component of the Bexsero^® anti-meningococcal vaccine, was used to evaluate the technique in comparison with other epitope mapping methods. The PROFILER technology readily identified NadA fragments that were capable of fully recapitulating the reactivity of the entire antigen against mAb 9F11. Further analysis of these fragments using mutagenesis and hydrogen-deuterium exchange mass-spectrometry allowed us to identify the binding site of mAb 9F11 (A250-D274) and an adjoining sequence (V275-H312) that was also required for the full functional reconstitution of the epitope. These data suggest that, by virtue of its ability to detect a great variety of immunoreactive antigen fragments in phage-displayed libraries, the PROFILER technology can rapidly and reliably identify epitope-containing regions and provide, in addition, useful clues for the functional characterization of conformational mAb epitopes.     

Pyridoxine/pyridoxamine 5′-phosphate oxidase (Sgll/PNPO) is important for DNA integrity and glucose homeostasis maintenance in Drosophila

Pyridoxine/pyridoxamine 5′-phosphate oxidase (PNPO) and pyridoxal kinase (PDXK) cooperate to produce pyridoxal 5′-phosphate (PLP), the active form of vitamin B6. PDXK phosphorylates pyridoxine, pyridoxamine, and pyridoxal by producing PNP, PMP, and PLP, whereas PNPO oxidizes PNP, PMP, into PLP. We previously demonstrated that PDXK depletion in Drosophila and human cells impacts on glucose metabolism and DNA integrity. Here we characterized sgll, the Drosophila ortholog of PNPO gene, showing that its silencing by RNA interference elicits chromosome aberrations (CABs) in brains and induces diabetic hallmarks such as hyperglycemia and small body size. We showed that in sgll^RNAi neuroblasts CABs are largely produced by the genotoxic effect of the advanced glycation end products triggered by high glucose. As in sgll^RNAi cells, part of PLP is still produced by PDXK activity, these data suggest that PLP dosage need to be tightly regulated to guarantee glucose homeostasis and DNA integrity.     

The First Mitogenome of the Cyprus Mouflon (Ovis gmelini ophion): New Insights into the Phylogeny of the Genus Ovis

Sheep are thought to have been one of the first livestock to be domesticated in the Near East, thus playing an important role in human history. The current whole mitochondrial genome phylogeny for the genus Ovis is based on: the five main domestic haplogroups occurring among sheep (O. aries), along with molecular data from two wild European mouflons, three urials, and one argali. With the aim to shed some further light on the phylogenetic relationship within this genus, the first complete mitochondrial genome sequence of a Cypriot mouflon (O. gmelini ophion) is here reported. Phylogenetic analyses were performed using a dataset of whole Ovis mitogenomes as well as D-loop sequences. The concatenated sequence of 28 mitochondrial genes of one Cypriot mouflon, and the D-loop sequence of three Cypriot mouflons were compared to sequences obtained from samples representatives of the five domestic sheep haplogroups along with samples of the extant wild and feral sheep. The sample included also individuals from the Mediterranean islands of Sardinia and Corsica hosting remnants of the first wave of domestication that likely went then back to feral life. The divergence time between branches in the phylogenetic tree has been calculated using seven different calibration points by means of Bayesian and Maximum Likelihood inferences. Results suggest that urial (O. vignei) and argali (O. ammon) diverged from domestic sheep about 0.89 and 1.11 million years ago (MYA), respectively; and dates the earliest radiation of domestic sheep common ancestor at around 0.3 MYA. Additionally, our data suggest that the rise of the modern sheep haplogroups happened in the span of time between six and 32 thousand years ago (KYA). A close phylogenetic relationship between the Cypriot and the Anatolian mouflon carrying the X haplotype was detected. The genetic distance between this group and the other ovine haplogroups supports the hypothesis that it may be a new haplogroup never described before. Furthermore, the updated phylogenetic tree presented in this study determines a finer classification of ovine species and may help to classify more accurately new mitogenomes within the established haplogroups so far identified.     

Susceptibility to Antibiotics of Vibrio sp. AO1 Growing in Pure Culture or in Association with its Hydroid Host Aglaophenia octodonta (Cnidaria, Hydrozoa)

Vibrio harveyi is the major causal organism of vibriosis, causing potential devastation to diverse ranges of marine invertebrates over a wide geographical area. These microorganisms, however, are phenotypically diverse, and many of the isolates are also resistant to multiple antibiotics. In a previous study, we described a previously unknown association between Vibrio sp. AO1, a luminous bacterium related to the species V. harveyi, and the benthic hydrozoan Aglaophenia octodonta. In this study, we analyzed the susceptibility to antibiotics (ampicillin, streptomycin, tetracycline, or co-trimoxazole = mix of sulfamethoxazole and trimetoprim) of Vibrio sp. AO1 growing in pure culture or in association with its hydroid host by using microcosm experiments. The results of minimum inhibitory concentration (MIC) experiments demonstrated that Vibrio sp. AO1 was highly resistant to ampicillin and streptomycin in pure culture. Nevertheless, these antibiotics, when used at sub-MIC values, significantly reduced the hydroid fluorescence. Co-trimoxazole showed the highest inhibitory effect on fluorescence of A. octodonta. However, in all treatments, the fluorescence was reduced after 48 h, but never disappeared completely around the folds along the hydrocaulus and at the base of the hydrothecae of A. octodonta when the antibiotic was used at concentration completely inhibiting growth in vitro. The apparent discrepancy between the MIC data and the fluorescence patterns may be due to either heterogeneity of the bacterial population in terms of antibiotic susceptibility or specific chemical–physical conditions of the hydroid microenvironment that may decrease the antibiotic susceptibility of the whole population. The latter hypothesis is supported by scanning electron microscope evidence for development of bacterial biofilm on the hydroid surface. On the basis of the results obtained, we infer that A. octodonta might behave as a reservoir of antibiotic multiresistant bacteria, increasing the risk of their transfer into aquaculture farms.