Notch Signaling & MicroRNAs - two tumblers of neurogenesis and Gliomas.

Gliomas are one of the most annihilating types of brain tumours having a high rate of annual incidence worldwide. Notch signaling is an evolutionary conserved pathway that regulates differentiation and development. Aberrations in Notch signalling pathways lead to severe pathological state such as the Gliomas. MicroRNAs (miRNAs) are the tiny molecules less than 200 bps in length and regulate a myriad of cellular processes. Categorically, miRNAs are divided in to oncogenic and tumours suppressor miRNAs. Accumulating data have identified miRNAs, which positively or negatively regulate Notch signaling in Gliomas. Here, we have assessed status of our understanding of the interplay between miRNA-base regulation of Notch signaling in gliomas, interaction between Notch signaling and other signaling cascades and have also discussed use of natural compounds that will help us get closer to personalized medicine for gliomas.

Pilot scale production of recombinant hemicellulases and their saccharification potential.

Synergistic saccharification ability of hemicellulases (endo-xylanase and ß-xylosidase) was evaluated in this study for the bioethanol production from plant biomass. Endo-xylanase and ß-xylosidase genes from Bacillus licheniformis were cloned and expressed in Escherichia coli BL21 (DE3). Maximum endo-xylanase production was obtained at 200 rpm agitation speed, air supply rate 2.0 vvm, 70% volume of the medium, 20% dissolved oxygen level and with 3% inoculum size. The optimal conditions for maximum production of recombinant ß-xylosidase enzyme at pilot scale were 200 rpm agitation speed, 25% dissolved oxygen level, 2.5 vvm aeration rate, 70% volume of the medium with 2% inoculum size. Furthermore, the saccharification potential of these recombinant enzymes was checked for the production of xylose sugar by bioconversion of plant biomass by optimizing individually as well as synergistically by optimizing various parameters. Maximum saccharification (93%) of plant biomass was observed when both enzymes were used at a time with 8% sugarcane bagasse as a substrate and 200 units of each enzyme after incubation of 6 hr at 50 °C and 120 rpm. The results obtained in this study suggested these recombinant hemicellulases as potential candidates for the conversion of complex agricultural residues into simple sugars for ultimate use in the biofuel industry.

Pilot-scale production of a highly thermostable α-amylase enzyme from Thermotoga petrophila cloned into E. coli and its application as a desizer in textile industry.

In this study, the industrial applications of a highly thermostable α-amylase as a desizer in the textile industry was evaluated. The cloned gene was expressed in different media (ZBM, LB, ZYBM9, and ZB) with IPTG (isopropyl ß-d-1-thiogalactopyranoside) used as an inducer. Lactose was also used as an alternate inducer for the T7 promoter system in E. coli. For the large-scale production of the enzyme, different parameters were optimized. The maximum enzyme production was achieved when the volume of medium was 70% of the total volume of fermenter with a 2.0 vvm air supply and 20% dissolved oxygen at a 200 rpm agitation rate. Under all the optimized conditions, the maximum enzyme production was 22.08 U ml-1 min-1 with lactose (200 mM) as an inducer in ZBM medium. The desizing potential of the purified α-amylase enzyme was calculated with different enzyme concentrations (50-300 U ml-1) at different temperatures (50-100 °C), and pHs (4-9) with varying time intervals (30-120 min). The highest desizing activity was found when 150 U ml-1 enzyme units were utilized at 85 °C and at 6.5 pH for 1 h.

Purification and Characterization of a recombinant ß-Xylosidase from Bacillus licheniformis ATCC 14580 into E. coli Bl21.

Present research work is aimed to purify and characterize a recombinant ß-xylosidase enzyme which was previously cloned from Bacillus licheniformis ATCC 14580 in to Escherichia coli BL21. Purification of recombinant enzyme was carried out by using ammonium sulphate precipitation method followed by single step immobilized metal ion affinity chromatography. Specific activity of purified recombinant ß-xylosidase enzyme was 20.78 Umg-1 with 2.58 purification fold and 33.75% recovery. SDS-PAGE was used to determine the molecular weight of recombinant purified ß-xylosidase and it was recorded as 52 kDa. Purified enzyme showed stability upto 90°C within a pH range of 3-8 with and optimal temperature and pH, 55ºC and 7.0, respectively. The enzyme activity was not considerably affected in the presence of EDTA. An increase in the enzyme activity was found in the manifestation of Mg+2. Enzyme activity was also increased by 6%, 18% and 22% in the presence of 1% Tween 80, ß-mercaptoethanol and DTT, respectively. Higher concentrations (10 - 40%) of organic solvents did not show any effect upon activity of enzyme. All these characteristics of the recombinant enzyme endorsed it as a potential candidate for biofuel industry.

Detection of resistance, cross-resistance, and stability of resistance to new chemistry insecticides in Bemisia tabaci (Homoptera: Aleyrodidae).

Resistance levels in whitefly, Bemisia tabaci (Gennadius) collections from cotton and sunflower (up to four districts) for five neonicotinoids and two insect growth regulators (IGRs) were investigated for two consecutive years. Based on the LC50(s), all collections showed slight to moderate levels of resistance for the tested insecticides compared with the laboratory susceptible population. The data also indicated that cotton and sunflower collections had similar resistance levels. In comparison (four collections), Vehari collections showed higher resistance for acetamiprid, thiacloprid, and nitenpyram compared with those of others. Average resistance ratios for acetamiprid, thiacloprid, and nitenpyram ranged from 5- to 13-, 4- to 8-, and 9- to 13-fold, respectively. Multan and Vehari collections also exhibited moderate levels (9- to 16-fold) of resistance to buprofezin. Furthermore, toxicity of neonicotinoids against immature stages was equal to that of insect growth regulators. The data also suggested that resistance in the field populations was stable. After selection for four generations with bifenthrin (G1 to G4), resistance to bifenthrin increased to 14-fold compared with the laboratory susceptible population. Selection also increased resistance to fenpropathrin, lambdacyhalothrin, imidacloprid, acetamiprid, and diafenthuron. Cross-resistance and stability of resistance in the field populations is of some concern. Rotation of insecticides having no cross-resistance and targeting the control against immature stages may control the resistant insects, simultaneously reducing the selection pressure imposed.

Evidence of field-evolved resistance to organophosphates and pyrethroids in Chrysoperla carnea (Neuroptera: Chrysopidae).

The toxicity of some of the most commonly used insecticides in the organophosphate and pyrethroid classes were investigated against different Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) populations collected over three consecutive years (2005-2007). The populations were tested using leaf dip bioassays for residual effects and topical applications to measure the response of larvae that would come into direct contact with field application of insecticides. In leaf dip assays, the LC50 (micrograms per milliliter; 120 h) values for chlorpyrifos and profenofos were in the range of 59.3-1,023 and 180.02-1,118 respectively. The LC50 values for lambda-cyhalthrin, alphamethrin, and deltamethrin were 359.08-2,677, 112.9-923.5, and 47.81-407.03, respectively. The toxicity for the above insecticides in topical application was similar to toxicity in leaf dip assays. The susceptibility of a laboratory population, which was locally developed and designated as (Lab-PK), to deltamethrin was comparable with another susceptible laboratory population. Resistance ratios for five field populations were generally low to medium for deltamethrin, but high to very high for chlorpyrifos, profenofos, lambda-cyhalthrin and alphamethrin compared with the Lab-PK population. Our data also suggested that the five field populations had multiple resistance to two classes of insecticides. The populations showed resistance to two organophosphates tested and to lambda-cyhalthrin and alphamethrin; however, resistance to deltamethrin was only found at two locations. This pattern indicates occurrence of two divergent patterns of resistance within pyrethroids. The resistance to the insecticides was stable across 3 yr, suggesting field selection for general fitness had also taken place in various populations of C. carnea. The broad spectrum of resistance and stability of resistance to insecticides in C. carnea in the current study suggested that it could be a prime candidate for mass releases and compatible with most spray programs.