Insects are well adapted to changing environmental conditions. They have unique systems for eliminating reactive oxygen species (ROS). Superoxide dismutase (SOD) is a key enzyme that plays a primary role in removing ROS. Bombyx mori is a lepidopteran insect, whose body size is larger than the model insect Drosophila melanogaster, which enabled us to more easily examine gene expression at the tissue level. We searched B. mori SOD (BmSOD) genes using genome database, and we analyzed their function under different type of oxidative stress. Consequently, we identified four new types of BmSODs in addition to the three types already known. Two of the seven types had a unique domain architecture that has not been discovered previously in the SOD family, and they were expressed in different tissues and developmental stages. Furthermore, these BmSODs responded differently to several kinds of stressors. Our results showed that the seven types of BmSODs are likely to play different roles in B. mori; therefore, B. mori could be used to distinguish the functions of each SOD for resistance to oxidative stress that changes with the environmental conditions.

Next-generation sequencing has revolutionized entomological study, rendering it possible to analyze the genomes and transcriptomes of non-model insects. However, use of this technology is often limited to obtaining the nucleotide sequences of target or related genes, with many of the acquired sequences remaining unused because other available sequences are not sufficiently annotated. To address this issue, we have developed a functional annotation workflow for transcriptome-sequenced insects to determine transcript descriptions, which represents a significant improvement over the previous method (functional annotation pipeline for insects). The developed workflow attempts to annotate not only the protein sequences obtained from transcriptome analysis but also the ncRNA sequences obtained simultaneously. In addition, the workflow integrates the expression-level information obtained from transcriptome sequencing for application as functional annotation information. Using the workflow, functional annotation was performed on the sequences obtained from transcriptome sequencing of the stick insect (Entoria okinawaensis) and silkworm (Bombyx mori), yielding richer functional annotation information than that obtained in our previous study. The improved workflow allows the more comprehensive exploitation of transcriptome data and is applicable to other insects because the workflow has been openly developed on GitHub.

Purification and properties of three types of xylanases produced by an alkalophilic actinomycete. Journal of Applied Bacteriology 69, 3 9 8 4 5 .Three types of xylanases (1,4-/?-D-Xyh xylanohydrolase, EC 3.2.1.8) were isolated from the culture filtrate of an alkalophilic actinomycete, Nocardiopsis dassonvillei subsp. alba OPC-18. The enzymes (X-I, X-I1 and X-111) were purified by acetone precipitation, chromatographies of DEAE-cellulofine A-800, Sephadex G-75 and preparative isoelectric focusing. The purified enzymes showed single bands on sodium dodecyl sulphate polyacrylamide gel electrophoresis. The molecular weights of X-I, X-I1 and X-111 were 23 OOO, 23 OOO and 37 OOO. respectively. The PIS were 4.9 (X-I), 5.3 (X-11) and 4.1 (X-111). The optimum pH levels for the activity of X-I and X-I1 were pH 7.0. X-111 was also most active at pH 7.0, but 62.5% of the activity remained even at pH 11. The optimum temperatures for the activities of X-I and X-I1 were 60°C and that of X-111 was 50°C. X-1 and X-I1 were stable in the range of pH 6-10, and X-111 was stable in the range of pH 8-12 until 40°C for 30min.

Two types of xylanases (1,4-0-D-xylan xylanohydrolase, EC 3.2.1.8) were isolated from the culture filtrate of a thermophilic actinomycete, Streptomyces thermoviolaceus OPC-520. The enzymes (STX-I and STX-II) were purified by chromatography with DEAE-Toyopearl 650 M, CM-Toyopearl 650 M, Sephadex G-75, Phenyl-Toyopearl 650 M, and Mono Q HR. The purified enzymes showed single bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular weights of STX-I and STX-II were 54,000 and 33,000, respectively. The pls were 4.2 (STX-I) and 8.0 (STX-II). The optimum pH levels for the activity of STX-I and STX-II were pH 7.0. The optimum temperature for the activity of STX-I was 70°C, and that for the activity of STX-II was 60°C. The enzymes were completely inhibited by N-bromosuccinimide. The enzymes degraded xylan, producing xylose and xylobiose as the predominant products, indicating that they were endoxylanases. STX-I showed high sequence homology with the exoglucanase from Cellulomonasfimi (47% homology), and STX-II showed high sequence homology with the xylanase from Bacillus pumilus (46% homology).

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