Isolation, Expansion, and Nucleofection of Neural Stem Cells from Adult Murine Subventricular Zone.

Isolation and expansion of neural stem cells (NSCs) from the subventricular zone (SVZ) of the adult mouse brain can be achieved in a medium supplemented with basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) as mitogens, producing clonal aggregates known as neurospheres. This in vitro system is a valuable tool for studying NSC potential. Transfection of siRNAs or genes carried in plasmids can be used to induce perturbations to gene expression and study NSC biology. However, the exogenous nucleic acid delivery to NSC cultures is challenging due to the low efficiency of central nervous system (CNS) cells transfection. Here, we present an improved nucleofection system that achieves high efficiency of gene delivery in expanded NSCs from adult murine SVZ. We demonstrate that this relatively simple method enhances gene perturbation in adult NSCs, surpassing traditional transfection protocols with survival rates exceeding 80%. Moreover, this method can also be applied in primary isolated NSCs, providing a crucial advancement in gene function studies through gene expression manipulation via knockdown or overexpression in neurosphere cultures.

Plant-microbe interactions: Mining heritable root-associated microbiota across environments.

The root-associated microbiota represents an untapped reservoir of beneficial functions for plants. A new study begins unravelling the host genetic determinants governing these interactions across environments, which will be a key step towards the development of novel climate-smart crops.

Effect of Gelled Emulsions Elaborated with Soybean Oil, Maca (Lepidium meyenni) Flour, and Chincho (Tagetes elliptica Sm.) Essential Oil upon Animal Fat Substitution in Beef Burgers.

The aim of this study was to analyze the effect of pork backfat (PB) substitution in a meat burger with a gelled emulsion (GE) elaborated with maca flour, soybean oil, and chincho essential oil (CEO). Lipid profile (gas chromatography­GC), health indices, physicochemical properties (CIELAB color, pH, texture profile­TPA), and cooking and sensory characteristics of meat burgers were analyzed. Five formulations were evaluated: control (BC) (80% beef meat and 20% PB); BSM (10% PB + 10% GE); BSMC0.25 (BSM + 0.25% CEO); BSMC0.5 (BSM + 0.5% CEO), and BSMC1.0 (BSM + 1.0% CEO). GE substitution in meat burgers provided a healthier lipid profile; the amount of SFA was reduced (p < 0.05), while PUFA content was significantly increased (p < 0.05). Furthermore, the use of GE resulted in healthier PUFA/SFA ratios and lower atherogenic and thrombogenic indices. The addition of GE increased moisture content and decreased fat and protein contents. Color parameters (L*, b*, and C*) decreased after cooking. Hardness (p < 0.05), cooking losses, and shrinkage changes decreased with GE addition. Lipid oxidation levels were significantly (p < 0.05) affected by GE substitution. Therefore, the substitution of PB by GE can be considered as an effective strategy to produce healthier meat burgers without negatively affecting their physicochemical and technological properties.

Multiresidue analysis of pesticides in soil by high-performance liquid chromatography with tandem mass spectrometry.

An analytical multiresidue method using HPLC/MS/MS with a triple-quadrupole mass spectrometer in the multiple reaction monitoring mode for the simultaneous determination of 54 pesticides in soil has been developed. The procedure involved initial single-phase extraction of soil sample with acetonitrile by sonication, followed by liquid-liquid partitioning after addition of NaCI. The average recovery by the HPLC/MS/MS method obtained for these compounds varied from 63.2 to 113.8%, with an RSD between 1.9 and 7.1%. The method gave good linearity over the assay range of 10-500 microg/L (except famoxadone, 50-1000 microg/L); the LOD and LOQ for the pesticides varied from 0.02 to 13.2 and from 0.1 to 43.9 microg/kg, respectively. The proposed method was used to determine pesticide levels in soil samples from two experimental vineyards and two tomato greenhouses.

Mannan Molecular Substructures Control Nanoscale Glucan Exposure in Candida.

Cell wall mannans of Candida albicans mask ß-(1,3)-glucan from recognition by Dectin-1, contributing to innate immune evasion. Glucan exposures are predominantly single receptor-ligand interaction sites of nanoscale dimensions. Candida species vary in basal glucan exposure and molecular complexity of mannans. We used super-resolution fluorescence imaging and a series of protein mannosylation mutants in C. albicans and C. glabrata to investigate the role of specific N-mannan features in regulating the nanoscale geometry of glucan exposure. Decreasing acid labile mannan abundance and α-(1,6)-mannan backbone length correlated most strongly with increased density and nanoscopic size of glucan exposures in C. albicans and C. glabrata, respectively. Additionally, a C. albicans clinical isolate with high glucan exposure produced similarly perturbed N-mannan structures and elevated glucan exposure geometry. Thus, acid labile mannan structure influences the nanoscale features of glucan exposure, impacting the nature of the pathogenic surface that triggers immunoreceptor engagement, aggregation, and signaling.

Shared Transcriptional Control and Disparate Gain and Loss of Aphid Parasitism Genes.

Aphids are a diverse group of taxa that contain agronomically important species, which vary in their host range and ability to infest crop plants. The genome evolution underlying agriculturally important aphid traits is not well understood. We generated draft genome assemblies for two aphid species: Myzus cerasi (black cherry aphid) and the cereal specialist Rhopalosiphum padi. Using a de novo gene prediction pipeline on both these, and three additional aphid genome assemblies (Acyrthosiphon pisum, Diuraphis noxia, and Myzus persicae), we show that aphid genomes consistently encode similar gene numbers. We compare gene content, gene duplication, synteny, and putative effector repertoires between these five species to understand the genome evolution of globally important plant parasites. Aphid genomes show signs of relatively distant gene duplication, and substantial, relatively recent, gene birth. Putative effector repertoires, originating from duplicated and other loci, have an unusual genomic organization and evolutionary history. We identify a highly conserved effector pair that is tightly physically linked in the genomes of all aphid species tested. In R. padi, this effector pair is tightly transcriptionally linked and shares an unknown transcriptional control mechanism with a subset of ∼50 other putative effectors and secretory proteins. This study extends our current knowledge on the evolution of aphid genomes and reveals evidence for an as-of-yet unknown shared control mechanism, which underlies effector expression, and ultimately plant parasitism.

Pesticide residue analysis of vegetables by gas chromatography with electron-capture detection.

A new and original analytical method was developed for the routine analysis of 28 multiclass pesticide residues in vegetables (green pepper, red pepper, and tomato). The extraction was performed with acetone, and the pesticides were partitioned into ethyl acetate-cyclohexane (1 + 1, v/v). Residue levels in vegetables were determined by gas chromatography (GC) with electron-capture detection. Residue identities were confirmed by GC coupled with mass spectrometry in the selected ion monitoring mode. The average recoveries in pepper and tomato obtained for all analytes studied were 67.3 and 123.1%, respectively, with relative standard deviation between 1.8 and 7.0%. The detection limit for the pesticides studied varied from 0.1 to 2.6 microg/kg. The proposed method was applied to the analysis of these compounds in vegetables grown in experimental greenhouses.

Multiresidue analysis of pesticides in soil by gas chromatography with nitrogen-phosphorus detection and gas chromatography mass spectrometry.

A rapid multiresidue method for the simultaneous determination of 25 fungicides and insecticides in soil was developed. Soil samples are extracted by sonication with a water-acetonitrile mixture, and the pesticides are partitioned into dichloromethane. Final determination was made by gas chromatography (GC) with nitrogen-phosphorus detection (NPD). Confirmation analysis of pesticides was carried out by GC-MS in the selected ion monitoring (SIM) mode. The identification of compounds was based on retention time and on comparison of the primary and secondary ions. The average recovery by the GC-NPD method obtained for these compounds varied from 68.5% to 112.1% with a relative standard deviation between 1.8% and 6.2%. The GC-NPD method presents good linearity over the range assayed 50-2000 microg/L, and the detection limit for the pesticides studied varied from 0.1 to 10.4 microg/kg. The proposed method was used to determine pesticide levels in soil samples from experimental greenhouse pepper cultivation.

Rate of loss of insecticides during soil solarization and soil biosolarization.

This paper reports the use of solarization and biosolarization to decontaminate a soil polluted with six insecticides (buprofezin, pirimicarb, pirimiphos methyl, pyridaben, pyriproxyfen and tebufenpyrad). In the experiment, 17-L pots filled with clay-loam soil were placed in a greenhouse during the summer season and then contaminated with the insecticides of interest. Treatments consisted of different solarization and biosolarization treatments, including a control without disinfection. For both solarization and biosolarization treatments, low-density polyethylene film was used as cover; the biosolarization treatment involving application of a mixture of sheep and chicken manures at a rate of 400 g pot(-1). Five pots per treatment were sampled periodically up to 90 d after the beginning of each treatment. The results showed that both solarization and biosolarization enhanced the degradation rates of most of the insecticides tested compared with the control, probably as a result of the increased soil temperature. Pirimicarb, pirimiphos methyl, tebufenpyrad, pyriproxyfen and pyridaben were degraded to a greater extent in the biosolarization than in the solarization treatment. The results confirm that both solarization and biosolarization can be considered as a remediation tool for soils polluted by these insecticides.

Determination of 48 pesticides and their main metabolites in water samples by employing sonication and liquid chromatography-tandem mass spectrometry.

In this work, a rapid and sensitive analytical multiresidue method has been developed for the simultaneous determination of 48 pesticides and 19 metabolites in waters (tap, leaching and sewage), using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with triple quadrupole in selected reaction monitoring (SRM) mode. The procedure involves initial single phase extraction of samples with acetonitrile by sonication, followed by liquid-liquid partition aided by "salting out" process using NaCl. Matrix influence on recoveries was evaluated for the three waters. More than 50% of the compound presented very low signal suppression. The method presents good linearity over the range assayed 10-500 µg L(-1) and the most frequent detection limits was 0.05 ng mL(-1). The average recovery by the LC-MS/MS method obtained for these compounds varied from 74.6 to 111.2% with a relative standard deviation between 2.5 and 8.9%. The proposed method was used to determine pesticides levels in leaching water samples from 5 lysimeters from an experimental greenhouse located in Murcia.