Effect of dsHaHMGR on fecundity, larval production and number of spermatophores in <i>Helicoverpa armigera</i>.

<p>Two-day-old female pupae were treated with 1 µg of HaHMGR double-stranded RNA (dsHaHMGR) or enhanced green fluorescent protein double-stranded RNA (dsEGFP) (negative control). One female treated with dsRNA (dsHaHMGR or dsEGFP) was paired with an untreated male in a small cage (N = 30). Values are expressed in absolute terms as a percentage or as the mean ± SD. Values with the same letter are not significantly different at the <i>P</i>>0.05 level (ANOVA followed by Tukey’s post-hoc test).</p

Effects of <i>Helicoverpa armigera</i> HMGR (HaHMGR) RNA interference (RNAi) on the oviposition of <i>H.</i><i>armigera</i>.

<p>Twenty dsRNA-treated or nuclease-free water-treated females were mated with untreated males in cages (40 cm×30 cm×30 cm). The enhanced green fluorescent protein double-stranded RNA (dsEGFP) treatment group was used as a negative control. Nuclease-free water was used as a blank control. Histograms represent the average oviposition per female. Values with the same letter are not significantly different at the <i>P</i>>0.05 level (ANOVA followed by Tukey’s post-hoc test).</p

Neighbor-joining phylogenetic tree of the amino acid sequences of HMGR by Molecular Evolutionary Genetics Analysis Software Version 4.0 (MEGA4).

<p>The branches were statistically evaluated by bootstrap analysis. All sequences were from GenBank.</p

The relative expression of <i>Helicoverpa armigera</i> HMGR (HaHMGR) and vitellogenin in <i>H.</i><i>armigera</i> after injecting dsRNA.

<p>(A) Histograms represent the expression of HaHMGR after injecting HaHMGR double-stranded RNA (dsHaHMGR). (B) The expression of vitellogenin after injecting dsHaHMGR. The enhanced green fluorescent protein double-stranded RNA (dsEGFP) treatment group was used as a negative control, and nuclease-free water was used as a blank control. Values with the same letter are not significantly different at the <i>P</i>>0.05 level (ANOVA followed by Tukey’s post-hoc test).</p

RNAi Silencing of the HaHMG-CoA Reductase Gene Inhibits Oviposition in the <i>Helicoverpa armigera</i> Cotton Bollworm

<div><p>RNA interference (RNAi) has considerable promise for developing novel pest control techniques, especially because of the threat of the development of resistance against current strategies. For this purpose, the key is to select pest control genes with the greatest potential for developing effective pest control treatments. The present study demonstrated that the 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase; HMGR) gene is a potential target for insect control using RNAi. HMGR is a key enzyme in the mevalonate pathway in insects. A complete cDNA encoding full length HMGR (encoding an 837-aa protein) was cloned from <i>Helicoverpa armigera</i> (Lepidoptera: Noctuidae). The HaHMGR (<i>H. armigera</i> HMGR) knockdown using systemic RNAi <i>in vivo</i> inhibited the fecundity of the females, effectively inhibited ovipostion, and significantly reduced vitellogenin (Vg) mRNA levels. Moreover, the oviposition rate of the female moths was reduced by 98% by silencing HaHMGR compared to the control groups. One-pair experiments showed that both the proportions of valid mating and fecundity were zero. Furthermore, the HaHMGR-silenced females failed to lay eggs (approximate 99% decrease in oviposition) in the semi-field cage performance. The present study demonstrated the potential implications for developing novel pest management strategies using HaHMGR RNAi in the control of <i>H. armigera</i> and other insect pests.</p></div

On the Polarization of Gamma Ray Bursts and their Optical Afterglows

The polarization of the optical afterglow (AG) of Gamma-Ray Bursts (GRBs) has only been measured in a few instances at various times after the GRB. In all cases except the best measured one (GRB 030329) the observed polarization and its evolution are simple and easy to explain in the most naive version of the "Cannonball'' model of GRBs: the "intrinsic" AG polarization is small and the observations reflect the "foreground" effects of the host galaxy and ours. The polarization observed in GRB 030329 behaves chaotically, its understanding requires reasonable but ad-hoc ingredients. The polarization of the gamma rays of a GRB has only been measured in the case of GRB 021206. The result is debated, but similar measurements would be crucial to the determination of the GRB-generating mechanism