A novel antibacterial peptide that shows antibacterial activity against Staphylococcus aureus was isolated from the hemolymph of the silkworm, Bombyx mori. The novel peptide consisted of 42 amino acids and was highly basic. This peptide indicated no significant similarity with other antibacterial peptides. The peptide showed antibacterial activity against several Gram-negative and -positive bac...

Bombyx mori nuclear polyhedrosis virus (BmNPV) is an important pathogen of silkworms. Despite extensive studies in recent decades, the interaction between BmNPV and host cells is still not clearly understood. Autophagy is an intrinsic innate immune mechanism and it controls infection autonomously in virus-infected cells. In this study, we found that BmNPV infection could trigger autophagy, as d...

Antimicrobial peptides are small-molecule proteins that are usually encoded by multiple-gene families. They play crucial roles in the innate immune response, but reports on the functional divergence of antimicrobial peptide gene families are rare. In this study, 14 paralogs of antimicrobial peptides belonging to cecropin, moricin and gloverin families were recombinantly expressed in pET express...

Many promoters have been used to drive expression of heterologous transgenes in insects. One major obstacle in the study of non-model insects is the dearth of useful promoters for analysis of gene function. Here, we investigated whether the promoter of the immediate-early gene, ie1, from the Bombyx mori nucleopolyhedrovirus (BmNPV) could be used to drive efficient transgene expression in a wide...

Human papillomavirus 6b L1 virus-like particles (VLPs) were successfully expressed using Bombyx mori nucleopolyhedrovirus (BmNPV) bacmid expression system and rapidly purified using size exclusion chromatography after ultracentrifugation procedure and characterized by capillary zone electrophoresis (CZE). The average capillary electrophoresis migration time was 11 min with the relative standard...

Autographa californica nucleopolyhedrovirus (AcMNPV) does not replicate in Bombyx mori cells (Bm5, BmN). We have shown previously that when a short DNA sequence within AcMNPV ORF95, which encodes the viral helicase P143, is replaced with the colinear region of B. mori nucleopolyhedrovirus (BmNPV), AcMNPV gains the ability to replicate in Bm5 cells. To determine the mutational events in the p143...

An octapeptide, GAGAGAGY, was obtained by a novel method, i.e. hydrolysing Bombyx mori silk fibroin. Afterward, a dodecanoic acid-peptide conjugation was synthesized. This amphiphile assembled into cylindrical nanofibers of planar β-sheets at pH 9 and twisted β-sheets at pH 4.

In mulberry silkworm Bombyx mori, tRNA1(Gly) constitutes a multigene family from which the individual members are transcribed at different levels in vitro in homologous nuclear extracts. We report here the quantification of functional transcripts of these gene copies in vivo in B. mori-derived BmN cells based on a suppression assay. The gene copies were converted to encode suppressor tRNAs and ...

In this study, we developed a structure-based approach to identify Helitrons in four lepidopterans and systematically analysed Helitrons in the silkworm genome. We found that the content of Helitrons varied greatly among genomes. The silkworm genome harboured 67,555 Helitron-related sequences that could be classified into 21 families and accounted for ≈ 4.23% of the genome. Thirteen of the fami...

For a decade, mystery has surrounded the mechanisms by which piRNA biogenesis yields distinct size classes of small RNAs within individual PIWI proteins. In this issue of Cell, two studies shed light on this process, identifying conserved PARN-family exonucleases that trim piRNAs to their mature size in silkworms and C. elegans.