RNA elimination machinery targeting meiotic mRNAs promotes facultative heterochromatin formation

Facultative heterochromatin that changes during cellular differentiation coordinates regulated gene expression, but its assembly is poorly understood. Here, we describe facultative heterochromatin islands in fission yeast and show that their formation at meiotic genes requires factors that eliminate meiotic messenger RNAs (mRNAs) during vegetative growth. Blocking production of meiotic mRNA or loss of RNA elimination factors, including Mmi1 and Red1 proteins, abolishes heterochromatin islands. RNA elimination machinery is enriched at meiotic loci and interacts with Clr4/SUV39h, a methyltransferase involved in heterochromatin assembly. Heterochromatin islands disassemble in response to nutritional signals that induce sexual differentiation. This process involves the antisilencing factor Epe1, the loss of which causes dramatic increase in heterochromatic loci. Our analyses uncover unexpected regulatory roles for mRNA-processing factors that assemble dynamic heterochromatin to modulate gene expression.     

Technological classification of basque cider apple cultivars according to their polyphenolic profiles by pattern recognition analysis

The polyphenolic compositions of 31 Basque cider apple cultivars were determined in pulp, peel, and juice by high-performance liquid chromatography--diode array detection analysis of crude extracts and after thiolysis. Data sets, consisting of individual polyphenol concentrations, total procyanidin content, and the average degree of polymerization of procyanidins, were evaluated by multivariate chemometric techniques, to develop decision rules for classifying apple cultivars technologically into bitter and nonbitter categories. A preliminary study of the data structure was performed by cluster analysis and principal component analysis in each apple material. Bitter apple varieties presented higher contents of flavan-3-ols and/or dihydrochalcones than nonbitter cultivars. Different classification systems for the two categories on the basis of the chemical data were obtained applying several supervised pattern recognition procedures, such as linear discriminant analysis, K-nearest neighbors, soft independent modeling of class analogy, partial least-squares, and multilayer feed forward artificial neural networks. Excellent performance in terms of recognition and prediction abilities for both categories (100% of hits) was achieved in every case (pulp, peel, or juice). Polyphenolic profiles of apple pulp, peel, or juice provide enough information to develop classification criteria for establishing the technological group of apple cultivars (bitter or nonbitter).     

Polyphenolic profiles of Basque cider apple cultivars and their technological properties

The polyphenolic compositions of 31 Basque cider apple cultivars were determined in pulp, peel, and juice by high-performance liquid chromatography with diode array detection analysis of crude extracts and after thiolysis. Total polyphenols are distributed in a wide concentration range depending on the cultivar. Procyanidins are the class of polyphenols that present major concentrations in apple. Their average degrees of polymerization range from 4 to 8 depending on the cultivar. Apple cultivars were technologically classified into bitter and nonbitter categories using different classification systems obtained by applying several pattern recognition techniques, such as principal component analysis, K-nearest neighbors, soft independent modeling of class analogy, partial least-squares, and multilayer feed-forward-artificial neural networks, to apple pulp, peel, or juice data (individual polyphenol concentrations, total procyanidin content, and the average degree of polymerization of procyanidins). Bitter apple cultivars present higher contents of flavan-3-ols and/or dihydrochalcones than nonbitter cultivars. Detailed knowledge of the polyphenolic profile of each apple cultivar affords information about their susceptibility to oxidation, their sensory properties (bitterness, astringency), and their possible influence on the characteristics and quality of the final product (juice, cider) when apples are processed.     

UHPLC-MS analysis of juvenile hormone II in Mediterranean corn borer (Sesamia nonagrioides) hemolymph using various ionization techniques

The juvenile hormones (JHs) have been considered the most versatile hormones in the animal kingdom. JH-II is the most abundant JH in Sesamia nonagrioides, important maize pests in the Mediterranean basin. This study compared the sensitivities and matrix effects of four ionization modes on analyzing JH-II in S. nonagrioides hemolymph using ultrahigh-performance liquid chromatography-mass spectrometry (UHPLC-MS) in single ion monitoring (SIM) mode. The ionization techniques tested were electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), atmospheric pressure photoionization (APPI), and APPI with the lamp turned off, which corresponds to atmospheric pressure thermospray ionization (APTSI). ESI was discarded because of the high matrix effect. APPI was discarded because the correlation responses between solvent and matrix on the instrumental quality parameters were worse than those for APTSI and APCI. In our analytical conditions, APCI has shown the best validation parameter values. APCI ionization is widely available in instrumental laboratories.     

Identification and validation of SNPs in the phytoene synthase 2 (psy2) gene associated with yellow color of the root in cassava (Manihot esculenta Crantz) accessions of the Brazilian Amazon

Genetic Resources and Crop Evolution - The biofortification of cassava (Manihot esculenta Crantz) roots is one of the actual goals of genetic breeding, with the development of roots richer in...     

Chemometric characterization of fruit juices from Spanish cultivars according to their phenolic compound contents: I. Citrus fruits

The data set composed by phenolic compound profiles of 83 Citrus juices (determined by HPLC-DAD-MS/MS) was evaluated by chemometrics to differentiate them according to Citrus species (sweet orange, tangerine, lemon, and grapefruit). Cluster analysis (CA) and principal component analysis (PCA) showed natural sample grouping among Citrus species and even the Citrus subclass. Most of the information contained in the full data set can be captured if only 15 phenolic compounds (concentration ≥10 mg/L), which can be quantified with fast and accurate methods in real samples, are introduced in the models; a good classification which allows the confirmation of the authenticity of juices is achieved by linear discriminant analysis. Using this reduced data set, fast and routine methods have been developed for predicting the percentage of grapefruit in adulterated sweet orange juices using principal component regression (PCR) and partial least-squares regression (PLS). The PLS model has provided suitable estimation errors.     

Fleets of robots for environmentally-safe pest control in agriculture

Feeding the growing global population requires an annual increase in food production. This requirement suggests an increase in the use of pesticides, which represents an unsustainable chemical load for the environment. To reduce pesticide input and preserve the environment while maintaining the necessary level of food production, the efficiency of relevant processes must be drastically improved. Within this context, this research strived to design, develop, test and assess a new generation of automatic and robotic systems for effective weed and pest control aimed at diminishing the use of agricultural chemical inputs, increasing crop quality and improving the health and safety of production operators. To achieve this overall objective, a fleet of heterogeneous ground and aerial robots was developed and equipped with innovative sensors, enhanced end-effectors and improved decision control algorithms to cover a large variety of agricultural situations. This article describes the scientific and technical objectives, challenges and outcomes achieved in three common crops.     

Seed and juice characterization of pomegranate fruits grown in Tunisia: Comparison between sour and sweet cultivars revealed interesting properties for prospective industrial applications

Tunisian pomegranate genetic resources consist of sweet and sour cultivars, showing large morphometric variability. In the present work we characterized seeds and juice contents of sugars and organic acids of 5 sour and 7 sweet pomegranate cultivars. Results showed that citric acid was predominant in sour pomegranates, while malic acid was the most prevalent in sweet ones. Paradoxically, sour cultivars have higher sugar content than the sweet ones. A strong correlation was found between sourness and citric acid content, which is assumed to be the major factor that determines sour taste in pomegranate fruits. Besides, some of the seed parameters showed a significant positive correlation with acidity. Sweet cultivars were appropriate for fresh consumption and juice production due to several attributes in addition to their sweetness. Equally, sour pomegranate showed several characteristics that could be of great interest for food and nutraceutical industries.     

Oocyst output and transmission rates during successive infections with Eimeria acervulina in experimental broiler flocks

The infection dynamics of Eimeria species determine the clinical manifestation of the disease coccidiosis in poultry flocks, and a better understanding of the dynamics may contribute to improvement of control measures. Our aim was to study the course of infection and the transmission of Eimeria acervulina in groups of broilers by quantifying the transmission rate parameter and oocyst output. Three transmission experiments were carried out with groups of 20 male SPF broilers. At 2 days of age, one bird in each trial was orally inoculated with five sporulated E. acervulina oocysts (D0 post-inoculation, pi). One day after inoculation (D1 pi), the inoculated bird was housed with 19 non-inoculated contact birds. Individual faecal droppings were examined daily from D3-D32 pi to quantify the number of oocysts per gram faeces. The inoculated bird started shedding oocysts at D5 pi and contact birds between D10 and D17 pi. Contact birds that became infected due to oocyst excretion by the inoculated bird were characterized as first generation contact birds (C1). Contact birds excreting from D15 pi onwards (C2) became infected after the first C1 birds had started shedding and were considered to belong to a successive generation of the flock infection. Oocyst output was significantly lower for C1 compared to C2 birds, but the transmission rate parameter remained constant for both infection generations. These results suggest that although oocyst load increases, the transmission rate of E. acervulina remains constant between successive generations of infection in a flock.     

Effect of moderate Cu supplementation on serum metabolites, enzymes and redox state in feedlot calves

The aim of this investigation was to evaluate whether, in the nutritional management of commercial feedlots, copper (Cu) supplementation is justified to maintain the physiological requirements. This study compared beef calves fed concentrates with an average Cu basal content of 5 and 8 mg/kg in growing and finishing periods (10 animals) or supplemented with 15 mg/kg for each phase (20 animals) as regards production indices, metabolic parameters [glucose, nonesterified fatty acids (NEFA), cholesterol, serum urea nitrogen (SUN), creatinine, total serum protein (TSP), albumin, aspartate transaminase (AST) and γ-glutamyl transferase (GGT)] and markers of oxidative stress (reactive oxygen species (ROS) and serum antioxidant capacity (SAC)). Data were recorded at ages 12, 24 and 36 weeks. In general, Cu supplementation was neither detrimental nor beneficial for animal health and performance, and the levels of the measured metabolites and enzymes were within their normal ranges stated for feedlot with the same management during the whole study. However, in keeping with reported higher hepatic Cu levels at slaughter, animals on supplemented feed had higher GGT activities at the end of the finishing stage, although the difference was not statistically significant. On the other hand, lower SAC levels at the end of the growing period in the supplemented group suggest the possibility of a positive effect of Cu supplementation on redox state. Further research is necessary to clarify the potential role of Cu in limiting the ROS production associated with fattening diets, and to evaluate the hepatobiliary consequences of supplementation, including hepatic Cu accumulation.