Inversions and gene order shuffling in Anopheles gambiae and A. funestus

In tropical Africa, Anopheles funestus is one of the three most important malaria vectors. We physically mapped 157 A. funestus complementary DNAs (cDNAs) to the polytene chromosomes of this species. Sequences of the cDNAs were mapped in silico to the A. gambiae genome as part of a comparative genomic study of synteny, gene order, and sequence conservation between A. funestus and A. gambiae. These species are in the same subgenus and diverged about as recently as humans and chimpanzees. Despite nearly perfect preservation of synteny, we found substantial shuffling of gene order along corresponding chromosome arms. Since the divergence of these species, at least 70 chromosomal inversions have been fixed, the highest rate of rearrangement of any eukaryote studied to date. The high incidence of paracentric inversions and limited colinearity suggests that locating genes in one anopheline species based on gene order in another may be limited to closely related taxa.     

Potato sprout inhibition and tuber quality after treatment with high-energy ionizing radiation

The use of industrial-type linear accelerators may be an alternative treatment for controlling sprouts in potatoes during long-term storage. The technical aspect of treatment has been described and may include largescale treatment of bulk potatoes as they are moving along a system of conveyors either to or from storage. The objective of the study was to evaluate the use of a linear accelerator for long-term sprout control under commercial storage conditions and the effects on tuber quality. An 18-MeV linear accelerator was used to provide sprout-inhibiting irradiation to various lots of ‘Russet Burbank’ potatoes. Successful sprout suppression was achieved with doses of 40 to 50 Gy (0 g sprout weight after 9 months of storage at 7.2 C) while higher doses caused undesirable increases in reducing sugars in the tubers. Glucose concentrations of treated tubers (0.25% fresh tuber weight) were higher after treatment than the untreated controls (0.08%), but returned to control levels after 2 to 6 months in storage. Glucose concentrations in treated tubers were significantly reduced with storage management for reconditioning by increasing the storage temperature for one month (from 7.2 C to 14.4 C) resulting in glucose concentrations near control concentrations. By increasing the dose-rate from the accelerator, recovery of tuber glucose concentration due to radiation treatments was significantly faster than when the dose was given more slowly. Potato tubers irradiated with high rates (100 Gy) of high-energy electrons exhibited an increase in soft rot and dry rot incidence in storage. Disease development in potatoes treated with sprout inhibiting doses of radiation (50 Gy) increased in lots with a high rot potential. Treated lots with low rot potential were successfully stored for 8 months or more without an increase in rot potential or shrinkage. Selection of lots for irradiation treatment should include some preliminary evaluation for development of disease in long-term storage.     

In vitro Assessment of the Bioaccessibility of Carotenoids from Sun-Dried Chilli Peppers

Chilli peppers have been recognized as an excellent source of antioxidants as they are rich in bioactive phytochemicals such as carotenoids which are known to exert various beneficial effects in vivo. Absorption is an important factor in the determination of the potential biological effects of carotenoids. The bioaccessibility of a food constituent such as a carotenoid represents its potential to be absorbed in humans. There is very limited information in the literature regarding the content and bioaccessibility of carotenoids from dried peppers. Therefore, the objectives of the present study were: first, to determine the carotenoid content of 20 varieties of red, orange or yellow coloured sun-dried chilli peppers belonging to either of four Capsicum species (annuum, baccatum, chinense and chacoense); and second, to quantify the carotenoid micellarization (bioaccessibility) following an in vitro digestion procedure. Red peppers had a higher carotenoid content and bioaccessibility than either the orange peppers or yellow pepper. Xanthophylls showed greater bioaccessibility than carotenes. Our findings confirm that dried chilli peppers are a good source of carotenoids.     

First evidence of previously undescribed trichomonad species in the intestine of pigs?

Three different parasites of the phylum Parabasala (Tritrichomonas foetus, Trichomitus rotunda and Tetratrichomonas buttreyi) have been described in pigs. In a previous study (Mostegl et al., 2011) approximately 47% of 91 paraffin wax-embedded intestinal samples of pigs which were Trichomonas-positive by in situ hybridization using a probe with a broad reactivity spectrum contained other species than T. foetus. Out of these, intestinal trichomonads from three pigs (pigs 1-3) were further analyzed by gene sequencing of a part of the 18S ribosomal RNA (rRNA) gene using primer walking. Subsequently, the partial sequences achieved by the different primer pairs were combined to a sequence of about 1000 bp for each trichomonad. In all three pigs unique sequences were acquired which showed only moderate similarities to sequences available in the GenBank. Alignments and the BLAST analysis showed a high degree of homology between sequences of trichomonads from pig 1 and pig 3 with only 1% difference. These sequences were found to be 92% similar to Hypotrichomonas acosta, a trichomonad isolated from squamate reptiles. The trichomonad sequence detected in the intestine of pig 2 showed about 10% nucleotide differences compared to pigs 1 and 3. This sequence was 97% similar to two Trichomitus batrachorum (a frog symbiont) sequences. A phylogenetic analysis using the neighbor-joining and maximum likelihood methods supported the data of the BLAST analysis. These results suggest the presence of at least two as yet undescribed trichomonad species in the intestinal contents of pigs.     

Forum: Social-Ecological System Archetypes for European Rangelands

Rangelands in Europe are imprinted by livestock production and embedded in mosaic landscapes of grasslands, croplands, woodlands, and settlements. They developed as social-ecological systems: People managed rangelands in order to maintain or enhance their ecosystem services, which in turn supported their well-being. The appreciation of ecosystem services provided by rangelands depends on the broad, socioeconomic aspirations and abilities of the managers and the capital available to achieve these aspirations. Here we propose four archetypical social-ecological system representations for European rangelands along the dimensions of socioeconomic aspirations (i.e., oriented toward conventional or sustainable production) and available financial capital (i.e., low or high) to employ farming technologies on rangelands. The four archetypes are aspiration misfit, pockets of sustainability, techno-dependence, and money dependent sustainability. We describe the landscape physiognomy, ecosystem service appreciation, and management-related synergies and trade-offs in ecosystem services supply related to each archetype and formulate a number of research questions to document and further understand them as social-ecological systems. We include the importance of urbanization, land grabbing, and institutional networks in shaping the social-ecological archetypes of rangelands and the relationship between our social-ecological archetypes and the resilience and transformability of rangelands.     

Bioactivities of glycoalkaloids and their aglycones from Solanum species

Potatoes, tomatoes, and aubergines are all species of the Solanum genus and contain a vast array of secondary metabolites including calystegine alkaloids, phenolic compounds, lectins, and glycoalkaloids. Glycoalkaloids have been the subject of many literature papers, occur widely in the human diet, and are known to induce toxicity. Therefore, from a food safety perspective further information is required regarding their analysis, toxicity, and bioavailability. This is especially important in crop cultivars derived from wild species to prevent glycoalkaloid-induced toxicity. A comprehensive review of the bioactivity of glycoalkaloids and their aglycones of the Solanum species, particularly focused on comparison of their bioactivities including their anticancer, anticholesterol, antimicrobial, anti-inflammatory, antinociceptive, and antipyretic effects, toxicity, and synergism of action of the principal Solanum glycoalkaloids, correlated to differences of their individual molecular structures is presented.     

Damage caused by Alternaria alternata to the quality and germination of amaranth seeds

European Journal of Plant Pathology - Alternaria alternata is one of the main microorganisms responsible for affecting seeds and causing infection and eventually seed discoloration. The purpose of...