Relationship between epistasis and aggressiveness in resistance of pepper (Capsicum annuum L.) to Phytophthora nicotianae

This study evaluated the types of gene action governing the inheritance of resistance to Phytophthora nicotianae necrosis in populations derived from two crosses involving two susceptible (Beldi and Nabeul II) and one resistant (CM334) cultivars of pepper (Capsicum annuum L.). Populations, composed of Pr, Ps, F1 , F 2 , BC 1 Pr, and BC 1 Ps generations, were inoculated with six P. nicotianae isolates. Generation means analysis indicated that an additive-dominance model was appropriate for P. nicotianae isolates Pn Ko1 , Pn Ko2 and Pn Kr1 , which showed low aggressiveness in the two crosses. For the more aggressive isolates Pn Bz1 , Pn Bz2 and Pn Kr2 , epistasis was an integral component of resistance in the two crosses. The presence of epistasis in the resistance of pepper to P. nicotianae was dependent on the level of aggressiveness of the isolates. Selection in pepper with less aggressive isolates was efficient, but not with more aggressive isolates; on the other hand, selection with more aggressive isolates was more stable. The minimum number of genes controlling resistance was estimated at up to 2.71. In the majority of cases, the additive variance was significant and greater than the environmental and dominance variance

The effects of subchronic lithium administration in male Wistar mice on some biochemical parameters

Lithium salts are efficiently used for treatment of psychiatric disorders. However, prolonged treatment frequently involves adverse side effects. In this study, effects of lithium carbonate administration on some biochemical parameters were studied in male mice. Lithium carbonate (20, 40, or 80 mg/kg body weight corresponding to 3.77, 7.54, or 15.08 mg Li element/kg body weight, respectively) was injected daily for 14 or 28 days. The following parameters were recorded: drinking water consumption, body weight, lithium and testosterone serum concentrations, activities of catalase (CAT), superoxide-dismutase (SOD), and glutathione-peroxidase (GPX), and level of lipid peroxidation (expressed as TBARS) in liver was performed. Lithium treatment, especially at the highest dose for 28 days, was found to induce weight gain and polydipsia and a significant decrease of plasma testosterone level. Lipid peroxidation level and activities of SOD and GPX were increased in liver, which suggests a perturbation of the antioxidative status. Our results indicate that subchronic exposure to lithium, which induces weight gain and polydipsia under our experimental conditions, also damages the male reproductive system and triggers an oxidative stress in the liver. </jats:p

Neuroprotective Activity of Grape Seed and Skin Extract Against Lithium Exposure Using Proteomic Research

International audienceLithium (Li) has raised scientific concern because it represents a serious problem threatening human health. This study aimed firstly at analyzing and potentially quantifying the impact of Li and grape seed and skin extract (GSSE) separately and, secondly, describing the possible neuroprotective activity of GSSE against Li toxicity. To this end, rats were exposed for 30 days to different Li concentrations (0, 2, and 100 mg/kg bw), to GSSE (4000 mg/kg bw), and to binary mixture of Li and GSSE. Liquid chromatography (HPLC–MS/MS) analysis used for GSSE showed that 15 phenolic compounds are present in the extract. Significant modifications of proteins were detected in the brain using proteomics research after treatment. Proteins were successfully identified by a linear ion trap–Orbitrap mass spectrometer. These proteins can be roughly related to oxidative stress, glycolysis, signaling pathway, and inflammation. Additionally, proteins involved in cell junction such as myosin, spectrin, tubulin, ERM-binding phosphoprotein, and dynein were also affected by Li exposure. Dose response was detected for most expressed proteins after Li treatment. In contrast, GSSE induced the expression and/or the stabilization of some proteins changed after Li treatment in the brain showing its neuroprotective activity. These data demonstrate that proteomic analysis is a powerful tool to provide valuable insights into mechanisms of toxicity of Li in the nervous system of Wistar rats. To our knowledge, this is the first evidence of using GSSE as neuroprotective model against Li toxicity. These findings provide impetus for future investigation on GSSE against other toxic chemicals

Mood stabilizing drugs regulate transcription of immune, neuronal and metabolic pathway genes in Drosophila

Abstract: Lithium and valproate (VPA) are drugs used in the management of bipolar disorder. Even though they reportedly act on various pathways, the transcriptional targets relevant for disease mechanism and therapeutic effect remain unclear. Furthermore, multiple studies used lymphoblasts of bipolar patients as a cellular proxy, but it remains unclear whether peripheral cells provide a good readout for the effects of these drugs in the brain. We used Drosophila culture cells and adult flies to analyze the transcriptional effects of lithium and VPA and define mechanistic pathways. Transcriptional profiles were determined for Drosophila S2-cells and adult fly heads following lithium or VPA treatment. Gene ontology categories were identified using the DAVID functional annotation tool with a cut-off of p < 0.05. Significantly enriched GO terms were clustered using REVIGO and DAVID functional annotation clustering. Significance of overlap between transcript lists was determined with a Fisher's exact hypergeometric test. Treatment of cultured cells and adult flies with lithium and VPA induces transcriptional responses in genes with similar ontology, with as most prominent immune response, neuronal development, neuronal function, and metabolism. (i) Transcriptional effects of lithium and VPA in Drosophila S2 cells and heads show significant overlap. (ii) The overlap between transcriptional alterations in peripheral versus neuronal cells at the single gene level is negligible, but at the gene ontology and pathway level considerable overlap can be found. (iii) Lithium and VPA act on evolutionarily conserved pathways in Drosophila and mammalian models