Analysis of epigenetic stability and conversions in Saccharomyces cerevisiae reveals a novel role of CAF-I in position-effect variegation

Position-effect variegation (PEV) phenotypes are characterized by the robust multigenerational repression of a gene located at a certain locus (often called gene silencing) and occasional conversions to fully active state. Consequently, the active state then persists with occasional conversions to the repressed state. These effects are mediated by the establishment and maintenance of heterochromatin or euchromatin structures, respectively. In this study, we have addressed an important but often neglected aspect of PEV: the frequency of conversions at such loci. We have developed a model and have projected various PEV scenarios based on various rates of conversions. We have also enhanced two existing assays for gene silencing in Saccharomyces cerevisiae to measure the rate of switches from repressed to active state and vice versa. We tested the validity of our methodology in Δsir1 cells and in several mutants with defects in gene silencing. The assays have revealed that the histone chaperone Chromatin Assembly Factor I is involved in the control of epigenetic conversions. Together, our model and assays provide a comprehensive methodology for further investigation of epigenetic stability and position effects.     

CD8 alpha beta T cells are not essential to the pathogenesis of arthritis or colitis in HLA-B27 transgenic rats

The class I MHC allele HLA-B27 is highly associated with the human spondyloarthropathies, but the basis for this association remains poorly understood. Transgenic rats with high expression of HLA-B27 develop a multisystem inflammatory disease that includes arthritis and colitis. To investigate whether CD8alphabeta T cells are needed in this disease, we depleted these cells in B27 transgenic rats before the onset of disease by adult thymectomy plus short-term anti-CD8alpha mAb treatment. This treatment induced profound, sustained depletion of CD8alphabeta T cells, but failed to suppress either colitis or arthritis. To address the role of CD8alpha(+)beta(-) cells, we studied four additional groups of B27 transgenic rats treated with: 1) continuous anti-CD8alpha mAb, 2) continuous isotype-matched control mAb, 3) the thymectomy/pulse anti-CD8alpha regimen, or 4) no treatment. Arthritis occurred in approximately 40% of each group, but was most significantly reduced in severity in the anti-CD8alpha-treated group. In addition to CD8alphabeta T cells, two sizeable CD8alpha(+)beta(-) non-T cell populations were also reduced by the anti-CD8alpha treatment: 1) NK cells, and 2) a CD4(+)CD8(+)CD11b/c(+)CD161a(+)CD172a(+) monocyte population that became expanded in diseased B27 transgenic rats. These data indicate that HLA-B27-retricted CD8(+) T cells are unlikely to serve as effector cells in the transgenic rat model of HLA-B27-associated disease, in opposition to a commonly invoked hypothesis concerning the role of B27 in the spondyloarthropathies. The data also suggest that one or more populations of CD8alpha(+)beta(-) non-T cells may play a role in the arthritis that occurs in these rats.     

Losartan Improved Antioxidant Defense,Renal Function and Structure of Postischemic Hypertensive Kidney

Ischemic acute renal failure (ARF) is a highly complex disorder involving renal vasoconstriction, filtration failure, tubular obstruction, tubular backleak and generation of reactive oxygen species. Due to this complexity, the aim of our study was to explore effects of Angiotensin II type 1 receptor (AT1R) blockade on kidney structure and function, as well as oxidative stress in spontaneously hypertensive rats (SHR) after renal ischemia reperfusion injury. Experiments were performed on anaesthetized adult male SHR in the model of ARF with 40 minutes clamping the left renal artery. The right kidney was removed and 40 minutes renal ischemia was performed. Experimental groups received AT1R antagonist (Losartan) or vehicle (saline) in the femoral vein 5 minutes before, during and 175 minutes after the period of ischemia. Biochemical parameters were measured and kidney specimens were collected 24h after reperfusion. ARF significantly decreased creatinine and urea clearance, increased LDL and lipid peroxidation in plasma. Treatment with losartan induced a significant increase of creatinine and urea clearance, as well as HDL. Lipid peroxidation in plasma was decreased and catalase enzyme activity in erythrocytes was increased after losartan treatment. Losartan reduced cortico-medullary necrosis and tubular dilatation in the kidney. High expression of pro-apoptotic Bax protein in the injured kidney was downregulated after losartan treatment. Our results reveal that angiotensin II (via AT1R) mediates the most postischemic injuries in hypertensive kidney through oxidative stress enhancement. Therefore, blockade of AT1R may have beneficial effects in hypertensive patients who have developed ARF.     

Gene expression profiling through microarray analysis in Arabidopsis thaliana colonized by Pseudomonas putida MTCC5279, a plant growth promoting rhizobacterium

Plant growth promotion is a multigenic process under the influence of many factors; therefore an understanding of these processes and the functions regulated may have profound implications. Present study reports microarray analysis of Arabidopsis thaliana plants inoculated with Pseudomonas putida MTCC5279 (MTCC5279) which resulted in significant increase in growth traits as compared with non-inoculated control. The gene expression changes, represented by oligonucleotide array (24652 genes) have been studied to gain insight into MTCC5279 assisted plant growth promotion in Arabidopsis thaliana. MTCC5279 induced upregulated Arabidopsis thaliana genes were found to be involved in maintenance of genome integrity (At5g20850), growth hormone (At3g23890 and At4g36110), amino acid synthesis (At5g63890), abcissic acid (ABA) signaling and ethylene suppression (At2g29090, At5g17850), Ca⁺² dependent signaling (At3g57530) and induction of induced systemic resistance (At2g46370, At2g44840). The genes At3g32920 and At2g15890 which are suggested to act early in petal, stamen and embryonic development are among the downregulated genes. We report for the first time MTCC5279 assisted repression of At3g32920, a putative DNA repair protein involved in recombination and DNA strand transfer in a process of rapid meiotic and mitotic division.     

Structure-Activity Relationship of Methyl 4-Aminobenzoate Derivatives as Being Drug Candidate Targeting Glutathione Related Enzymes: in Vitro and in Silico Approaches

A thiol compound, glutathione, is essential for healthy cell defence against xenobiotics and oxidative stress. Glutathione reductase (GR) and glutathione S-transferase (GST) are two glutathione-related enzymes that function in the antioxidant and the detoxification systems. In this study, potential inhibitory effects of methyl 4-aminobenzoate derivatives on GR and GST were examined in vitro. GR and GST were isolated from human erythrocytes with 7.63 EU/mg protein and 5.66 EU/mg protein specific activity, respectively. It was found that compound 1 (methyl 4-amino-3-bromo-5-fluorobenzoate with K_i value of 0.325±0.012 μM) and compound 5 (methyl 4-amino-2-nitrobenzoate with K_i value of 92.41±22.26 μM) inhibited GR and GST stronger than other derivatives. Furthermore, a computer-aided method was used to predict the binding affinities of derivatives, ADME characteristics, and toxicities. Derivatives 4 (methyl 4-amino-2-bromobenzoate) and 6 (methyl 4-amino-2-chlorobenzoate) were estimated to have the lowest binding energies into GR and GST receptors, respectively according to results of in silico studies.     

Evolution and diversity of Arsenophonus endosymbionts in aphids

Endosymbiotic bacteria are important drivers of insect evolutionary ecology, acting both as partners that contribute to host adaptation and as subtle parasites that manipulate host reproduction. Among them, the genus Arsenophonus is emerging as one of the most widespread lineages. Its biology is, however, entirely unknown in most cases, and it is therefore unclear how infections spread through insect populations. Here we examine the incidence and evolutionary history of Arsenophonus in aphid populations from 86 species, characterizing the processes that shape their diversity. We identify aphids as harbouring an important diversity of Arsenophonus strains. Present in 7% of the sampled species, incidence was especially high in the Aphis genus with more than 31% of the infected species. Phylogenetic investigations revealed that these Arseno‐phonus strains do not cluster within an aphid‐specific clade but rather exhibit distinct evolutionary origins showing that they undergo repeated horizontal transfers (HT) between distantly related host species. Their diversity pattern strongly suggests that ecological interactions, such as plant mediation and parasitism, are major drivers for Arsenophonus dispersal, dictating global incidence across insect communities. Notably, plants hosting aphids may be important ecological arenas for global exchange of Arsenophonus, serving as reservoirs for HT.     

Micropropagation,encapsulation, and conservation of Decalepis salicifolia,a vanillin isomer containing medicinal and aromatic plant

In Vitro Cellular & Developmental Biology - Plant - An efficient in vitro propagation and synthetic seed production protocol was established for the conservation of Decalepis salicifolia (Bedd....     

Contrasting Effects of Farmyard Manure (FYM) and Compost for Remediation of Metal Contaminated Soil

We investigated effect of farm yard manure (FYM) and compost applied to metal contaminated soil at rate of 1% (FYM-1, compost-1), 2% (FYM-2, compost-2), and 3% (FYM-3, compost-3). FYM significantly (P < 0.001) increased dry weights of shoots and roots while compost increased root dry weight compared to control. Amendments significantly increased nickel (Ni) in shoots and roots of maize except compost applied at 1%. FYM-3 and -1 caused maximum Ni in shoots (11.42 mg kg^?1) and roots (80.92 mg kg^?1), respectively while compost-2 caused maximum Ni (14.08 mg kg^?1) and (163.87 mg kg^?1) in shoots and roots, respectively. Plants grown in pots amended with FYM-2 and compost-1 contained minimum Cu (30.12 and 30.11 mg kg^?1) in shoots, respectively. FYM-2 and compost-2 caused minimum zinc (Zn) (59.08 and 66.0 mg kg^?1) in maize shoots, respectively. FYM-2 caused minimum Mn in maize shoots while compost increased Mn in shoots and roots compared to control. FYM and compost increased the ammonium bicarbonate diethylene triamine penta acetic acid (AB-DTPA) extractable Ni and Mn in the soil and decreased Cu and Zn. Lower remediation factors for all metals with compost indicated that compost was effective to stabilize the metals in soil compared to FYM.     

Acetazolamide Inhibits the Level of Tyrosinase and Melanin: An Enzyme Kinetic,In Vitro,In Vivo,and In Silico Studies

Melanin is the major factor that determines skin color and protects from ultraviolet radiation. In present study we evaluated the anti‐melanogenesis effect of acetazolamide (ACZ) using four different approaches: enzyme kinetic, in vitro, in vivo and in silico. ACZ demonstrated significant inhibitory activity (IC₅₀ 7.895 ± 0.24 μm ) against tyrosinase as compared to the standard drug kojic acid (IC₅₀ 16.84 ± 0.64 μm ) and kinetic analyses showed that ACZ is a non‐competitive inhibitor without cytotoxic effect. In in vitro experiments, A375 human melanoma cells were treated with 20 or 40 μm of ACZ with or without 50 μm of l ‐DOPA. Western blot results showed that ACZ significantly (P < 0.05) decreased the expression level of tyrosinase at 40 μm . Zebrafish embryos were treated with 10, 20 or 40 μm of ACZ and of positive control kojic acid. At 72 h of treatment with ACZ and kojic acid, ACZ significantly (P < 0.001) decreased the embryos pigmentation to 40.8% of untreated embryos at the dose of 40 μm of ACZ while kojic acid decreased only 25.0% of pigmentation at the same dose of kojic acid. In silico docking were performed against tyrosinase using PyRx tool. Docking studies suggested that His244, Asn260 and His85 are the major interacting residues in the binding site of the protein. In conclusion, our results suggest that ACZ is a good candidate for the inhibition of melanin and it could be used as a lead for developing the drugs for hyperpigmentary disorders and skin whitening.     

A SNP-based genetic dissection of versatile traits in bread wheat (Triticum aestivum L.)

The continuous increase in global population prompts increased wheat production. Future wheat (Triticum aestivum L.) breeding will heavily rely on dissecting molecular and genetic bases of wheat yield and related traits which is possible through the discovery of quantitative trait loci (QTLs) in constructed populations, such as recombinant inbred lines (RILs). Here, we present an evaluation of 92 RILs in a bi-parental RIL mapping population (the International Triticeae Mapping Initiative Mapping Population [ITMI/MP]) using newly generated phenotypic data in 3-year experiments (2015), older phenotypic data (1997–2009), and newly created single nucleotide polymorphism (SNP) marker data based on 92 of the original RILs to search for novel and stable QTLs. Our analyses of more than 15 unique traits observed in multiple experiments included analyses of 46 traits in three environments in the USA, 69 traits in eight environments in Germany, 149 traits in 10 environments in Russia, and 28 traits in four environments in India (292 traits in 25 environments) with 7584 SNPs (292 × 7584 = 2 214 528 data points). A total of 874 QTLs were detected with limit of detection (LOD) scores of 2.01–3.0 and 432 QTLs were detected with LOD > 3.0. Moreover, 769 QTLs could be assigned to 183 clusters based on the common markers and relative proximity of related QTLs, indicating gene-rich regions throughout the A, B, and D genomes of common wheat. This upgraded genotype–phenotype information of ITMI/MP can assist breeders and geneticists who can make crosses with suitable RILs to improve or investigate traits of interest.