Annotated ESTs from various tissues of the brown planthopper Nilaparvata lugens: a genomic resource for studying agricultural pests.

Background: The brown planthopper (BPH), Nilaparvata lugens (Hemiptera, Delphacidae), is a serious insect pests of rice plants. Major means of BPH control are application of agricultural chemicals and cultivation of BPH resistant rice varieties. Nevertheless, BPH strains that are resistant to agricultural chemicals have developed, and BPH strains have appeared that are virulent against the resistant rice varieties.

Sterol biosynthesis by symbiotes: cytochrome P450 sterol C-22 desaturase genes from yeastlike symbiotes of rice planthoppers and anobiid beetles.

Rice planthoppers and anobiid beetles harbor intracellular yeastlike symbiotes (YLS), whose sterols are nutritionally advantageous for the host insects that cannot synthesize sterols. YLS of anobiid beetles synthesize ergosterol, whereas YLS of planthoppers produce ergosta-5,7,24(28)-trienol, which is a metabolic intermediate in the ergosterol biosynthetic pathway in yeasts. Since sterol C-22 desaturase (ERG5p, CYP61) metabolizes ergosta-5,7,24(28)-trienol into ergosta-5,7,22,24(28)-tetraenol, which is the penultimate compound in the ergosterol biosynthesis, we examined the gene of this enzyme to determine whether this enzyme works in the planthopper YLS.

In vitro cultivation of Wolbachia in insect and mammalian cell lines.

Wolbachia infecting the small brown planthopper, Laodelphax striatellus, were successfully maintained and cultivated in two insect and one mammalian cell lines. The bacteria with the planthopper ovary were introduced into the flasks with the cultures of the cell lines. The Wolbachia proliferated in mosquito (Aedes albopictus) and lepidopteran (Heliothis zea) cell lines and in the mouse cell line, L929.