RNA interference and functional characterization of a tergal gland alpha amylase in the German cockroach, Blattella germanica L.

German cockroach males possess tergal glands that secrete a combination of oligosaccharides, lipids and proteins. Four major proteins occur in the secretion, with one being the 63 kDa alpha-amylase Blattella germanica Tergal Gland protein-1 (BGTG-1). Denaturing and starch gel electrophoresis coupled with peptide sequencing verified amylase activity for the BGTG-1 protein. BGTG-1 gene expression profiles were determined by using quantitative real-time PCR to compare messenger RNA abundance among isolated tissues of males, females and gravid females. Differences in BGTG-1 gene expression occurred among male tissues, with tergal gland tissue showing the highest expression. Tissues of nongravid and gravid females had significantly lower expression in comparison with male tergal glands (gravid females lowest). RNA interference (RNAi) was used to silence BGTG-1 gene expression by injecting BGTG-1 homologous double-stranded RNA (dsRNA) into male cockroaches. Groups injected with BGTG-1 dsRNA showed ∼90% lower BGTG-1 gene and protein expression compared to controls, which correlated with lower amylase activity in colorimetric assays. However, behavioural assays comparing precopulatory behaviour and mating success between RNAi and control males did not reveal differences. These results connect amylase gene expression and activity in tergal gland tissue but suggest other factors, such as other tergal gland components, may contribute more strongly to mating success.

Characterization of five CYP4 genes from Asian citrus psyllid and their expression levels in Candidatus Liberibacter asiaticus-infected and uninfected psyllids.

Previously, we reported that Candidatus Liberibacter asiaticus (Las)-infected Diaphorina citri are characterized by lower levels of cytochrome P450 monooxygenases than uninfected counterparts. In the present study, we investigated expression levels of family 4 cytochrome P450 (CYP4) genes in Las-infected and uninfected D.citri adults. Five novel CYP4 genes (CYP4C67, CYP4DA1, CYP4C68, CYP4DB1 and CYP4G70) were identified. Four of the five CYP4 genes were expressed at significantly higher levels in uninfected than Las-infected males, whereas only one was expressed at significantly higher levels in uninfected than Las-infected females. These results suggest that levels of cytochrome P450 monooxygenases in D.citri may be linked to expression levels of these CYP4 genes. Expression of all five CYP4 genes was induced by exposure of D.citri to imidacloprid, suggesting their possible involvement in metabolism of this toxin. Higher expression of the five CYP4 genes was found in nymphs than adults, which is congruent with previous results indicating higher levels of cytochrome P450 monooxygenases in nymphs than adults. These five CYP4 genes may be promising candidates for RNA-interference to silence overexpression of genes associated with insecticide resistance in D.citri. These newly identified genes may also serve as DNA-based screening markers for cytochrome P450-mediated insecticide resistance in field populations of D.citri.

Control of neoclassical tearing modes by sawtooth control.

The onset of a neoclassical tearing mode (NTM) depends on the existence of a large enough seed island. It is shown in the Joint European Torus that NTMs can be readily destabilized by long-period sawteeth, such as obtained by sawtooth stabilization from ion-cyclotron heating or current drive. This has important implications for burning plasma scenarios, as alpha particles strongly stabilize the sawteeth. It is also shown that, by adding heating and current drive just outside the inversion radius, sawteeth are destabilized, resulting in shorter sawtooth periods and larger beta values being obtained without NTMs.

Alpha-tail production with ion-cyclotron-resonance heating of 4He-beam ions in JET plasmas.

Third-harmonic ion-cyclotron-resonance heating of 4He-beam ions has produced for the first time on the JET tokamak high-energy populations of 4He ions to simulate 3.5 MeV fusion-born alpha (alpha) particles. Acceleration of 4He ions to the MeV energy range is confirmed by gamma-ray emission from the nuclear reaction 9Be(alpha,ngamma) 12C and excitation of Alfvén eigenmodes. Concomitant electron heating and sawtooth stabilization are observed. The scheme could be used in next-step tokamaks to gain information on trapped alpha particles and to test alpha diagnostics in the early nonactivated phase of operation.

Antenatal diagnosis of congenital renal malformations using ultrasound.

Our objectives were to determine the accuracy of antenatal sonography for the detection of congenital renal malformations and to characterize the type of malformations, seen in a 3-year prospective study at a university-affiliated maternity hospital. Participants were 31,217 pregnant women, during the study period, and subjects were 65 fetuses in whom renal malformations were detected on antenatal ultrasound. Pelvic ultrasound scans were performed at least once between 20 and 37 weeks' gestation on all pregnant women attending the antenatal clinic of the hospital for the detection of renal malformations. Fetal urinary sampling, diversion procedures, or termination of pregnancy were carried out as required in those detected to have renal anomalies. Postnatal diagnosis was confirmed by sonography or autopsy. Diagnostic procedures and renal surgery were performed postnatally if indicated. Sixty-five fetuses (0.2 per cent) were diagnosed to have congenital renal malformation antenatally at a mean gestational age of 28.4 weeks. A dilated urinary system was seen in 39, cystic renal disease in 15, agenesis/hypoplasia in six, combined lesions in four, and a horseshoe kidney in one. Oligohydramnios was noted in 20 (31 per cent) pregnancies. Multiple congenital malformations associated with renal anomalies were detected in 12 pregnancies. Termination was carried out at 20 weeks in two pregnancies for lethal malformations; fetal urinary sampling was done in two fetuses with obstructed uropathy, and a vesicoamniotic shunt inserted in one. Postnatal ultrasound confirmed a dilated urinary system in 32, cystic renal dysplasia in 15, renal aplasia/hypoplasia in five, combined lesions in six, and a horseshoe and an ectopic kidney in one each. Five infants were found to be normal. There were seven stillbirths and seven neonatal deaths. Radionuclide scans showed obstruction in nine, decreased renal function in six, and absent renal functions in 10 infants. Micturating cystourethrography demonstrated reflux in 11 and a non-refluxing non-obstructive dilated renal system in five babies. Renal surgery was performed in nine infants. The conclusions drawn from this study were that antenatal detection of renal disease is fairly accurate, even in an extremely busy hospital and certain types of malformations reported in other studies were not observed, despite a large cohort.