The epitopes in wheat proteins for defining toxic units relevant to human health

Wheat-related disorders are well-studied health problems. Knowledge of the composition and amounts of epitopes present in a single wheat sample represents a significant gap, and the detailed wheat proteome datasets now available can provide the necessary information to carry out an estimation of allergen prediction for a single cultivar. The combined use of genome sequence and allergen databases, prediction methodology, and cereal chemistry results in better understanding of the level of toxicity present in the end-products produced from wheat flour. The workflow presented in this review provides information about the number and distribution of epitopes at single protein, or protein fraction, levels. In addition, epitopes present in the highest frequency and harmful proteins expressed in the highest amount can be identified. The “epitope toxicity” value obtained in this way is a significant research output from the analysis of large datasets that can be applied to the food industry.     

Diversity-dependent stability under mowing and nutrient addition: evidence from a 7-year grassland experiment

Anthropogenic perturbations may affect biodiversity and ecological stability as well as their relationships. However, diversity-stability patterns and associated mechanisms under human disturbances have rarely been explored. We conducted a 7-year field experiment examining the effects of mowing and nutrient addition on the diversity and temporal stability of herbaceous plant communities in a temperate steppe in northern China. Mowing increased population and community stability, whereas nutrient addition had the opposite effects. Stability exhibited positive relationships with species richness at population, functional group and community levels. Treatments did not alter these positive diversity-stability relationships, which were associated with the stabilising effect of species richness on component populations, species asynchrony and portfolio effects. Despite the difficulty of pinpointing causal mechanisms of diversity-stability patterns observed in nature, our results suggest that diversity may still be a useful predictor of the stability of ecosystems confronted with anthropogenic disturbances.     

Deep 16S rRNA metagenomics and quantitative PCR analyses of the premature infant fecal microbiota

Metagenomic studies on the gut microbiota of preterm infants are scarce. We characterized the microbiota of 10 days-old neonates by deep 16S rRNA gene metagenomic analysis and compare the results with those obtained by qPCR. Both techniques lead to similar conclusions, allowing differentiating between preterm and full-term infants.     

Pathways for ATP release by bovine ciliary epithelial cells, the initial step in purinergic regulation of aqueous humor inflow

ATP release by nonpigmented (NPE) and pigmented (PE) ciliary epithelial cells is the enabling step in purinergic regulation of aqueous humor formation, but the release pathways are unknown. We measured ATP release from primary cultures of bovine mixed NPE and PE (bCE) cells and transformed bovine NPE and PE cells, using the luciferin-luciferase reaction. Hypotonicity-triggered bCE ATP release was inhibited by the relatively selective blocker of pannexin-1 (PX1) hemichannels (probenecid, 1 mM, 47 ± 2%), by a connexin inhibitor (heptanol, 1 mM, 49 ± 4%), and by an inhibitor of vesicular release (bafilomycin A1, 25 ± 2%), but not by the P2X(7) receptor (P2RX(7)) antagonist KN-62. Bafilomycin A1 acts by reducing the driving force for uptake of ATP from the cytosol into vesicles. The reducing agent dithiothreitol reduced probenecid-blockable ATP release. Similar results were obtained with NPE and PE cell lines. Pannexins PX1-3, connexins Cx43 and Cx40, and P2RX(7) were identified in native cells and cell lines by RT-PCR. PX1 mRNA expression was confirmed by Northern blots; its quantitative expression was comparable to that of Cx43 by real-time PCR. Heterologous expression of bovine PX1 in HEK293T cells enhanced swelling-activated ATP release, inhibitable by probenecid. We conclude that P2RX(7)-independent PX1 hemichannels, Cx hemichannels, and vesicular release contribute comparably to swelling-triggered ATP release. The relatively large response to dithiothreitol raises the possibility that the oxidation-reduction state is a substantial regulator of PX1-mediated ATP release from bovine ciliary epithelial cells.     

Reproduction of the West Mediterranean endemic Arum pictum (Araceae) on Corsica

Pollination in the genus Arum appears to be in general a complex deceptive pollination process. The genus Arum is composed of 28 species, all belonging to the subgenus Arum, except A. pictum, the only species of the subgenus Gymnomesium, which is basal and sister to all other Arum species. The aim of this paper is to document the pollination ecology of the insular Arum pictum, the only Arum species to flower in autumn, on the island of Corsica (France). The anthesis cycle of A. pictum occurs during the day, attracting sphaerocerid flies and staphylinid beetles early in the morning and late in the afternoon of the first day. The pollen is released from the anthers early in the morning of the second day before the departure of the insects. Its thermogenic cycle matches the anthesis cycle with an original and unique, bimodal temperature pattern of the appendix (morning and afternoon), contrary to the unimodal pattern found in all other studied Arum species. Data from reproductive success and seed sets suggest that sexual reproduction in this species is limited by pollen (e.g. attracting lured insects) rather than by resources. The biology of this Western Mediterranean species appears to be different from other Western European Arum and close to some Eastern Mediterranean species. Further studies are needed to establish whether Arum pictum represents some ancestral stage or whether its peculiar biological traits are adapted to its insular distribution.     

Utilization of a major brown rust resistance gene in sugarcane breeding

Brown rust, caused by Puccinia melanocephala, has had devastating effects on sugarcane (Saccharum spp.) breeding programs and commercial production. The discovery of Bru1, a major gene conferring resistance to brown rust, represented a substantial breakthrough. Markers for Bru1 are the first available for sugarcane molecular breeding. The contribution of Bru1 towards brown rust resistance in the Canal Point (CP) sugarcane breeding program was determined as a means of directing future breeding strategies. Bru1 was detected in 285 of 1,072 (27 %) clones used for crossing; this germplasm represents the genetic base for cultivar development in Florida. The frequency of Bru1 was greatest in CP clones (42 %) and lowest among Louisiana clones (6 %). Bru1 was not detected in clones with year assignments before 1953. However, Bru1 frequency increased from 15 % (assignments 1975–1985) to 47 % in the current decade. The increase coincided with the introduction of brown rust to Florida. Bru1 was detected in 155 (32 %) of 485 parental clones tested for brown rust susceptibility at two field locations. Of clones classed resistant to brown rust, 154 (59 %) contained Bru1, yet none of 100 susceptible clones contained the gene. Bru1 was detected in 667 (44 %) clones in the second clonal stage of selection, 87 % of which were free of brown rust symptoms. Bru1 is the predominant source of resistance in the Florida sugarcane genetic base. Efforts to identify and integrate new brown rust resistance genes must be pursued to minimize risks associated with a future breakdown in major gene resistance provided by Bru1.