431 research outputs found
Composition of the rDNA loci of 18 iso-rDNA lines was determined by genomic blot analysis.
<p>Bar heights indicate the total number of rDNA units in each line. The shading of the bar indicates the number of units that are uninserted or inserted with R1, R2 or both elements. Asterisks indicate the six lines with the highest levels of R2 transcripts.</p
Distribution of R2 elements in the rDNA locus.
<p>High molecular weight DNA was prepared from 0–23 hr old embryo nuclei, digested with <i>Not</i>I, which cleaves only in the R2 element (see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000386#pgen-1000386-g001" target="_blank">Figure 1</a>), and separated by pulsed-field electrophoresis. Six lines with high levels of R2 transcripts (High) and six lines with little or no R2 transcripts (Low) were used in the analysis. After transfer to nitrocellulose the DNA was probed with a segment from the 18S rRNA gene <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000386#pgen.1000386-Eickbush3" target="_blank">[26]</a>. The DNA marker standard corresponds to a 50 kb ladder. Two samples (CS115 and A56) were analyzed on a separate gel under identical conditions. Also because of a lower DNA concentration in the nuclear plug, the CS22 lane represents a longer exposure of the DNA blot.</p
R2 elements and locus composition in 18 <i>D. simulans</i> lines.
<p>FL, full-length R2 copies; 5′ Trun, 5′ truncated R2 copies; Un, uninserted rDNA units; R1, R1-inserted units; R2, R2-inserted units.</p>*<p>Values include both single and R1+R2 (double) inserted units.</p
Relationship of R2 transcript levels to the size and composition of the rDNA locus.
<p>(A) The relative R2 transcript level of each line is plotted versus the number of full-length, thus potentially active, R2 elements in that line. (B) The level of R2 transcripts in each line is plotted versus the fraction of the rDNA units inserted with R2 elements. The fraction of the rDNA units inserted with R2 was determined using genomic blots (see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000386#s4" target="_blank">Materials and Methods</a>). (C) The level of R2 transcripts is plotted versus the size of the rDNA locus. The total number of units is determined by dividing the total number of R2 elements by the fraction of units inserted with R2 for each line.</p
R2 transcripts levels in the iso-rDNA lines derived from the Atlanta and San Diego populations.
<p>(A) Representative RNA blot using RNA isolated from 18 iso-rDNA lines and, as a positive control (lane labeled, +), laboratory line 58, known to have high levels of R2 transcription and retrotranspositions <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000386#pgen.1000386-Eickbush3" target="_blank">[26]</a>. The arrow indicates the 3,600 nt full-length R2 transcript. For each lane 10 µg of RNA isolated from adult females was fractionated on a 1% agarose gel, transferred to a nylon membrane, and probed with a 300 nt R2 5′ antisense RNA (probe1 in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000386#pgen-1000386-g001" target="_blank">Figure 1</a>). (B) As a control for RNA quality and loading the R2 hybridization signal was allowed to decay and the blot was re-probed with a fragment of the alcohol dehydrogenase gene <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000386#pgen.1000386-Eickbush3" target="_blank">[26]</a>. (C) Ethidium bromide staining of the RNAs used for the analyses in panels A and B.</p
Correlation between R2 transcript levels and the rate of R2 retrotransposition.
<p>The 18 iso-rDNA lines described in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000386#pgen-1000386-g003" target="_blank">Figures 3</a> and <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000386#pgen-1000386-g004" target="_blank">4</a> were assayed for R2 retrotransposition activity after eight generations. The R2 5′ truncation profiles of 16 males from the eighth generation were compared to the R2 profile from the original male used to establish each line. Because R2 deletions are also associated with R2 activity <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000386#pgen.1000386-Zhang3" target="_blank">[25]</a> loss of pre-existing insertions were also classified as R2 events. Because multiple R2 elements can be eliminated by a single deletion, all losses of R2 copies were scored as single events regardless of the number of R2 elements involved. For each line the total number of R2 events in all eighth generation males was plotted versus the R2 transcript level of that line.</p
R2 transcript levels of 180 iso-rDNA lines derived from populations in San Diego and Atlanta.
<p>The 3,600 nt full-length R2 transcript detected on RNA blots of adult female RNA (see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000386#pgen-1000386-g002" target="_blank">Figure 2</a>) were quantified on Phosphorimager scan and ImageQuant software. To control for RNA loading and possible degradation the R2 signal was standardized to the alcohol dehydrogenase signal from the same blot. RNA from line58, an active laboratory stock, was also present on every RNA blot as a standard to enable comparisons between blots. The 18 lines selected for further analysis to monitor R2 retrotranspositions and to determine the compositions of their rDNA loci are indicated with asterisks and labeled.</p
Effects of Cationic Polyacrylamide Characteristics on Sewage Sludge Dewatering and Moisture Evaporation
<div><p>The effects of the molecular weight (MW) and charge density (CD) of cationic polyacrylamide (CPAM) on sludge dewatering and moisture evaporation were investigated in this study. Results indicated that in sludge conditioning, the optimum dosages were 10, 6, 6, 4, and 4 mg g<sup>−1</sup> CPAM with 5 million MW and 20% CD, 5 million MW and 40% CD, 3 million MW and 40% CD, 8 million MW and 40% CD, and 5 million MW and 60% CD, respectively. The optimum dosage of CPAM was negatively correlated with its CD or MW if the CD or MW of CPAM was above 20% or 5 million. In the centrifugal dewatering of sludge, the moisture content in the conditioned sludge gradually decreased with the extension of centrifugation time, and the economical centrifugal force was 400×g. The moisture evaporation rates of the conditioned sludge were closely related to sludge dewaterability, which was in turn significantly correlated either positively with the solid content of sludge particles that were >2 mm in size or negatively with that of particles measuring 1 mm to 2 mm in diameter. During treatment, sludge moisture content was reduced from 80% to 20% by evaporation, and the moisture evaporation rates were 1.35, 1.49, 1.62, and 2.24 times faster in the sludge conditioned using 4 mg g<sup>−1</sup> CPAM with 5 million MW and 60% CD than in the sludge conditioned using 4 mg g<sup>−1</sup> CPAM with 8 million MW and 40% CD, 6 mg g<sup>−1</sup> CPAM with 5 million MW and 40% CD, 6 mg g<sup>−1</sup> CPAM with 3 million MW and 40% CD, and 10 mg g<sup>−1</sup> CPAM with 5 million MW and 20% CD, respectively. Hence, the CPAM with 5 million MW and 60% CD was ideal for sludge dewatering.</p></div
PI3K inhibitors suppress the activity of NADPH oxidase in seed germination.
<p>(A) In situ gel NBT assay. The PM fraction was separated by native PAGE, and the gel was incubated with NBT solution, then with 0.2 mM NADPH until the appearance of blue formazan bands was observed. The reaction was stopped by immersion of the gel in distilled water. (B) Quantitive analysis of the result of native PAGE in statistical method. (C) The seed embryos was immersed in the solution within the PI3K inhibitor for 12 hours, then isolate the plasma membrane, Plasma membrane vesicles (4 mg protein) were incubated with XTT at 25°C for 10 min. The reaction solution was used for spectrophotometric analysis of XTT formazan absorbance at A470. NADPH oxidase activity was expressed as ΔA470 per mg protein per min (ΔA470 represents the difference of XTT formazan absorbance at 470 nm in the presence and absence of superoxide dismutase [SOD]). Means of three replicates ± SD and the pictures represent typical examples. * indicates the values that are significantly different from control (P<0.05).</p
Centrifugal dewatering efficiency of sludge after conditioning with different CPAM types at optimum doses.
<p>Centrifugal dewatering efficiency of sludge after conditioning with different CPAM types at optimum doses.</p
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