Ready reference to common segmental aneusomies by syndromic names, major features and chromosomal locations

Abnormal gene dosage usually results in recognizable phenotypic abnormalities, especially if it involves a series of contiguous genes. Schmickel (1986) defined contiguous gene syndromes as diseases resulting from loss or gain of a series of adjacent genes. The terms microdeletion and microduplication as well as segmental aneusomy have also been used to describe such losses or gains that may not be readily detectable by Gbanded analysis. The loss (haploinsufficiency) or gain of a series of adjoining genes may result in a direct phenotypic effect and/or cause a genetic regulatory disturbance. Such syndromic gains or losses are often detectable when in situ hybridization of fluorescent labeled DNA probes or array comparative genomic hybridization technique are used (Gersen and Keagle 2005; Stumm et al. 1999; Barch, Knutsen and Spurbeck 1997). Segmental aneusomies generally occur due to homologous pairing between non-allelic low copy repeats (LCR) followed by crossing over. The LCRs, as part of the repetitive DNA sequences range from 1-500 Kb repeats, share >97% base sequence identity and constitute up to five percent of the genomic DNA. They are distributed throughout the genome, but are more concentrated near the centromeres and telomeres. A segment of 300 bp completely identical sequence within the LCRs is adequate for mediating non-allelic homologous or paralogous pairing. This process results in generating both deletion and duplication of a defined segment.     

Determination of key metabolites during biodegradation of hexahydro-1,3,5-trinitro-1,3,5-triazine with Rhodococcus sp. strain DN22.

Rhodococcus sp. strain DN22 can convert hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) to nitrite, but information on degradation products or the fate of carbon is not known. The present study describes aerobic biodegradation of RDX (175 microM) when used as an N source for strain DN22. RDX was converted to nitrite (NO(2)(-)) (30%), nitrous oxide (N(2)O) (3.2%), ammonia (10%), and formaldehyde (HCHO) (27%), which later converted to carbon dioxide. In experiments with ring-labeled [(15)N]-RDX, gas chromatographic/mass spectrophotometric (GC/MS) analysis revealed N(2)O with two molecular mass ions: one at 44 Da, corresponding to (14)N(14)NO, and the second at 45 Da, corresponding to (15)N(14)NO. The nonlabeled N(2)O could be formed only from -NO(2), whereas the (15)N-labeled one was presumed to originate from a nitramine group ((15)N-(14)NO(2)) in RDX. Liquid chromatographic (LC)-MS electrospray analyses indicated the formation of a dead end product with a deprotonated molecular mass ion [M-H] at 118 Da. High-resolution MS indicated a molecular formula of C(2)H(5)N(3)O(3). When the experiment was repeated with ring-labeled [(15)N]-RDX, the [M-H] appeared at 120 Da, indicating that two of the three N atoms in the metabolite originated from the ring in RDX. When [U-(14)C]-RDX was used in the experiment, 64% of the original radioactivity in RDX incorporated into the metabolite with a molecular weight (MW) of 119 (high-pressure LC/radioactivity) and 30% in (14)CO(2) (mineralization) after 4 days of incubation, suggesting that one of the carbon atoms in RDX was converted to CO(2) and the other two were incorporated in the ring cleavage product with an MW of 119. Based on the above stoichiometry, we propose a degradation pathway for RDX based on initial denitration followed by ring cleavage to formaldehyde and the dead end product with an MW of 119.     

Comparative bio-efficacy of nuclear polyhedrosis virus (NPV) and Spinosad against American bollwormm,Helicoverpa armigera (Hubner)

American bollworm (ABW), Helicoverpa armigera (Hubner), is considered as a major pest of cotton, Gossypium hirsutum, all over the globe. Due to its destructive feeding nature and continuous consumption of the same chemicals, it devolved resistant against many insecticides. Therefore, a combined application of bio- and synthetic-pesticide need to evaluate against this pest. The entomopathogenic viruses like nuclear polyhedrosis virus (NPV), a member of baculoviruses, can be the potential candidates for better control against ABW. The present study was conducted to assess the comparative efficacy of NPV and Spinosad 240SC (with the concentration of 250 mL · ha￣?) against ABW in the controlled environment. The ABW was treated with different concentrations of NPV and Spinosad separately and in a combination of NPV with 0.1% Spinosad. The results revealed that highest concentrations showed highest mortality (95%) followed by 95%, 92%, 84%, 82% and 78% mortality at 1 × 10⁹, 1 × 10⁸, 1 × 10⁷, 1 × 10⁶ and 1 × 10⁵ POBs, respectively. Spinosad when mixed in diet give 100% mortality at 0.8% followed by 50.87%, 42.10%, 29.82%, 26.31% and 22.80% mortality at 0.4%, 0.2%, 0.1%, 0.5% and 0.025% respectively. The results of this study revealed that microbial control of ABW through NPV is an effective tool. The repeated use of synthetic pesticides caused the resurgence of many insect pests, and this study results would provide useful insight to build a framework for future investigations for the management of many major insect pests.     

NPR1-dependent salicylic acid signaling is not involved in elevated CO2-induced heat stress tolerance in Arabidopsis thaliana

Elevated CO₂ can protect plants from heat stress (HS); however, the underlying mechanisms are largely unknown. Here, we used a set of Arabidopsis mutants such as salicylic acid (SA) signaling mutants nonexpressor of pathogenesis-related gene 1 (npr1-1 and npr1-5) and heat-shock proteins (HSPs) mutants (hsp21 and hsp70-1) to understand the requirement of SA signaling and HSPs in elevated CO₂-induced HS tolerance. Under ambient CO₂ (380 µmol mol⁻¹) conditions, HS (42°C, 24 h) drastically decreased maximum photochemical efficiency of PSII (Fv/Fm) in all studied plant groups. Enrichment of CO₂ (800 µmol mol⁻¹) with HS remarkably increased the Fv/Fm value in all plant groups except hsp70-1, indicating that NPR1-dependent SA signaling is not involved in the elevated CO₂-induced HS tolerance. These results also suggest an essentiality of HSP70-1, but not HSP21 in elevated CO₂-induced HS mitigation.     

Use of plant growth-promoting bacteria to enhance salinity stress in soybean (Glycine max L.) plants

The effects of three rhizobacterial isolates namely Pseudomonas fluorescens (M1), Pseudomonas putida (M2) and Bacillus subtilis (M3) were examined to enhance growth and chemical components such as chlorophyll and proline of three cultivars of soybean (Glycine max L.) under two levels of salinity stress (S1 = 200 mM and S2 = 400 mM of NaCl salt). Several morphological and physiological parameters were investigated. The highest mean values of final germination percent (FGP) were registered in cultivar Crawford (95%) followed by Giza111 cultivar (93%) in the presence of P. fluorescens, while, FGP of Clark was 85%. Mean germination time was decreased by the application of P. fluorescens or P. putida in both salt stressed and unstressed traits. All growth parameters were significantly decreased by salinity treatments, particularly at S2. A significant increase in stem length and shoot fresh weight was recorded in plants treated with P. fluorescens. This enhancing trend was followed by the application of P. putida then B. subtilis. Chlorophyll contents and plant soluble proteins were decreased, while proline content was increased as compared with control treatment. Results showed that the salt tolerant cultivar, Crawford, may have a better tolerance strategy against oxidative damages by increasing antioxidant enzymes activities under high salinity stress. These results suggest that salt induced oxidative stress in soybean is generally counteracted by enzymatic defense systems stimulated under harsh conditions. Our results showed that inoculation with plant growth-promoting rhizobacterial (PGPR) alleviated the harmful effects of salinity stress on soybean cultivars. The diversity in the phylogenetic relationship and in the level of genetic among cultivars was assessed by SDS-PAGE and RAPD markers. Among the polymorphism bands, only few were found to be useful as positive or negative markers associated with salt stress. The maximum number of bands (17) was recorded in Crawford, while the minimum number of bands (11) was recorded in Clark. Therefore, the ISSR can be used to identify alleles associated with the salt stress in soybean germplasm.     

Toxicity of Fe2O3 nanoparticles on human blood lymphocytes

Magnetic nanoparticles (NPs) are used to a large extent in the targeted delivery of therapeutic agents. In this study, we aimed to investigate the possible toxicity of Fe₂O ₃ NPs on human cells, including blood lymphocytes. We isolated blood lymphocytes from healthy humans using Ficoll polysaccharide and subsequently by gradient centrifugation. Then, the toxicity parameters, including cell viability, reactive oxygen species (ROS) formation, lipid peroxidation, cellular glutathione (GSH) level, mitochondrial and lysosomal damage, were measured in blood lymphocytes after exposure to Fe ₂O ₃ NPs. Our results indicated that Fe ₂O ₃ NPs significantly (dependent on concentration) reduced the cell viability, and the IC ₅₀ was determined to be 1 mM. With increasing concentrations, we found that Fe ₂O ₃ NPs–induced cell toxicity was associated with a significant increase in intracellular ROS and loss of mitochondrial membrane potential and lysosomal membrane leakiness. Consequently, these NPs at different concentrations affect GSH level and cause oxidative stress in human lymphocytes.