Silencing of Glutamine: Fructose-6-Phosphate Aminotransferase Impairs Growth and Development in Sogatella furcifera (Hemiptera: Delphacidae).

Glutamine: fructose-6-phosphate aminotransferase (GFAT), the fourth enzyme in the chitin synthesis pathway, exerts wide-ranging effects on the growth and development of organisms. However, the role of GFAT in Sogatella furcifera remains unknown. In this study, the functional significance of the GFAT gene of S. furcifera was analyzed using a reverse transcription-polymerase chain reaction and RNA interference (RNAi) analyses. The complementary DNA sequence of SfGFAT was 3162 bp in length and contained a 2067 bp open reading frame encoding 688 amino acid residues. Structural domain analysis indicated that the SfGFAT protein consisted of one glutamine aminotransferase class 2 domain and two sugar isomerase domains. Expression profile analysis revealed that SfGFAT was expressed throughout the egg, nymph, and adult phases and was strongly expressed on the first day of each nymph stage and in the integuments of five tissues. RNAi results revealed that SfGFAT gene silencing significantly inhibited the mRNA expression of the target gene and resulted in severe mortality among S. furcifera. In summary, these findings demonstrate that SfGFAT plays a critical role in the development of S. furcifera. Moreover, these results may aid in the development of methods to control the spread of S. furcifera.

Antiproliferative and Proapoptotic Effects of a Protein Component Purified from Aspongopus chinensis Dallas on Cancer Cells In Vitro and In Vivo.

Aspongopus chinensis Dallas is used as a traditional Chinese medicine. In China, clinical evidence suggests that it has anticancer activity. However, the anticancer active components are not fully elucidated. In the present study, we purified an anticancer active component (named CHP) from A. chinensis. To gain a comprehensive insight into the protein components, shotgun proteomic analysis was conducted. The anticancer active protein band was cut from the sodium dodecyl sulphate-polyacrylamide gel electrophoresis gel and digested with trypsin to generate peptide mixture. The peptide fragments were then analysed by liquid chromatography tandem mass spectrometry; 18 proteins were identified. In addition, we evaluated the effects of CHP on the proliferation and apoptosis of two human gastric cancer cell lines (SGC-7901 and BGC-823). The cultured cells were treated with CHP at concentrations of 20, 30, and 40 µg/mL. Inhibition of cell growth was determined by the MTT assay. Hoechst 33258 staining was adopted to detect apoptosis morphologically. Apoptotic cells were quantified by Annexin V-FITC/propidium iodide staining and flow cytometry. Tumour growth was assessed by subcutaneous inoculation of 4T1 cells into BALB/c mice. There was a concentration- and time-dependent decrease in the proliferation of both cell lines at CHP concentrations of 20-40 µg/mL. Apoptotic characteristics, such as karyopyknotic pyknic hyperfluorescence bolus and nuclear fragmentation, were observed in both the cell lines by Hoechst 33258 staining. Flow cytometry showed that CHP induced significant (P < 0.01) concentration-dependent apoptosis of SGC-7901 cells. In vivo assay showed that CHP can partially inhibit tumour growth derived from 4T1 cells in vivo. The present study is the first to report that CHP in A. chinensis inhibits the proliferation of cancer cell lines via the suppression of cancer cell proliferation and acceleration of apoptosis.

[Effects of spider mite and two substitute diets on the development and reproduction of Euseius nicholsi (Ehara et Lee) (Acari: Phytoseiidae)].

Three kinds of diets, i. e., two-spotted spider mite Tetranychus urticae Koch, Camellia oleifera Abel pollen, and mould mite Tyrophagus putrescentiae (Schrank), were used to feed Euseius nicholsi (Ehara et Lee) in laboratory at 25 degrees C and 80% RH to study the effects of these diets on the development and reproduction of E. nicholsi. The E. nicholsi could prey on T. putrescentiae egg, but could not complete its natural development due to the deficiency of the egg. Other two diets were the favorable foods for the normal growth and reproduction of E. nicholsi. The life cycle duration, longevity, oviposition duration, and average lifetime fecundity of the adult female E. nicholsi fed with C. oleifera pollen and T. urticae were 6.18 d, 24.79 d, 16.72 d and 23.03, and 5.67 d, 25.72 d 18.17 d and 25.38, respectively. The quantity of the experimental E. nicholsi populations fed with these two diets all showed an increasing trend, with the population tendency index being the highest (I = 14.28) for the population fed with C. oleifera pollen and the double population time being the shortest (t = 3.5201 days) for the population fed with T. urticae.