Genomic adaptation to polyphagy and insecticides in a major East Asian noctuid pest.

The tobacco cutworm, Spodoptera litura, is among the most widespread and destructive agricultural pests, feeding on over 100 crops throughout tropical and subtropical Asia. By genome sequencing, physical mapping and transcriptome analysis, we found that the gene families encoding receptors for bitter or toxic substances and detoxification enzymes, such as cytochrome P450, carboxylesterase and glutathione-S-transferase, were massively expanded in this polyphagous species, enabling its extraordinary ability to detect and detoxify many plant secondary compounds. Larval exposure to insecticidal toxins induced expression of detoxification genes, and knockdown of representative genes using short interfering RNA (siRNA) reduced larval survival, consistent with their contribution to the insect's natural pesticide tolerance.

An active recombinant cocoonase from the silkworm Bombyx mori: bleaching, degumming and sericin degrading activities.

Background: Cocoonase is a serine protease produced by silk moths and used for softening the cocoons so that they can escape. Degumming is one of the important steps in silk processing. This research aimed to produce an active recombinant Bombyx mori cocoonase (BmCoc) for the silk degumming process.

Physico-chemical properties and in vitro response of silk fibroin from various domestic races.

In this study, the characteristics of silk fibroin films obtained from regenerated aqueous silk fibroin solution of various races were evaluated. Three races based on original sources of silkworms were selected: Nangnoi-Sisaket 1 (NN), Nakhon Ratchasima 1 (K1), and Nakhon Ratchasima 2 (K8). The Tg and Td of silk fibroin films were around 147-156°C and 277-279°C, respectively.

Cloning and expression analysis of the Bombyx mori α-amylase gene (Amy) from the indigenous Thai silkworm strain, Nanglai.

α-Amylase is a common enzyme for hydrolyzing starch. In the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), α-amylase is found in both digestive fluid and hemolymph.