Project description:The silkworm, Bombyx mori, is a complete metamorphosis insect and an economically important for silk production, the model to study insect physiology and biochemistry. Bombyx mori nucleopolyhedrovirus (BmNPV) is a principal pathogen of the silkworm and its host range is restricted to silkworm larvae, requiring interaction with silkworm larvae to accomplish virus replication. Prothoracic glands (PGs) are a model for synthetic ecdysone with regulating insect growth and development. In this study, day-4 fifth instar silkworm larvae were infected by BmNPV, the wandering silkworms appeared in the infected groups were 12 hours earlier than that in the control groups, and the ecdysone titer in infected larvae was significantly higher than that of the control larvae. Then, we used RNA sequencing (RNA-seq) to analyze silkworm PGs 48 h after BmNPV infection. The classifications of the 15 differential expression genes (DEGs) were mainly involved in the metabolic processes and pathways. The RT-qPCR results of the DEGs in the PGs of BmNPV-infected at 24, 48, and 72 h were generally consistent with the transcriptome data. The transcripts of BmTrypsin-1 and BmACSS3 were significantly increased from 24 to 72 h after BmNPV infection that they may be involved in the maturation process in the latter half of silkworm fifth instar larvae. These findings will help to address the interactions between BmNPV infection and host developmental response.
Project description:Human utilization of the mulberry-silkworm interaction started at least 5,000 years ago and greatly influenced world history through the Silk Road. Complementing the silkworm genome sequence, here we describe the genome of a mulberry species (Morus notabilis C. K. Schneider). In the 330 Mb genome assembly of M. notabilis, we identified 128 Mb of repetitive sequences and 29,338 genes, 60.8% of which were supported by transcriptome sequencing. Mulberry gene sequences appear to evolve ~3 times faster than other Rosales, perhaps facilitating its spread to Europe, Africa, and America. It is among few eudicots but several Rosales not preserving genome duplications in more than 100 million years – however neopolyploid series in mulberry and several others suggest that new duplications may confer benefits. Strikingly, five predicted mulberry miRNAs were found in the hemolymph and silkglands of silkworm, suggesting profound molecular level interactions that promise to expand knowledge of plant-herbivore relationship which constitute key elements of most terrestrial habitats. In addition, we investigated the characters of hemolymph small RNA. small mRNA profiles of silkworm hemolymph in the fifth instar day-5 silkworm were generated by deep sequencing, in twice, using Illumina Hiseq 2000.
Project description:The aim of the study was to determine the protein composition of cornified claws of the western clawed frog (Xenopus tropicalis) in comparison to clawless toe tips and back skin. Cornified claws develop on toes I, II, III of the hind limbs, which we refer to as hind limb inner (HI) toes. Toes IV, V of the hind limbs, here referred to as hind limb outer (HO) toes lack claws. Proteins were prepared from HI toe tips including claws, HO toe tips and back skin (BSK) of frogs each (F1, F2, F3) and subjected to proteomic analysis.
Project description:Background: MicroRNA (miRNA) and other small regulatory RNAs contribute to the modulation of a large number of cellular processes. We sequenced three total RNA libraries prepared from the whole body, and the anterior and posterior silk glands of Bombyx mori, with a view to expanding the repertoire of silkworm miRNAs and exploring transcriptional differences in miRNAs between segments of the silk gland. Results: With the aid of large-scale Solexa sequencing technology, we validated 244 unique miRNA genes, including 191 novel and 53 previously reported genes, corresponding to 309 loci in the silkworm genome. Interestingly, 24 unique miRNAs were widely conserved from invertebrates to vertebrates; 12 unique ones were limited to invertebrates and 33 were confined to insects; whereas the majority of the newly identified miRNAs were silkworm-specific. We identified 21 clusters and 42 paralogs of miRNAs in the silkworm genome. However, sequence tags showed that paralogs or clusters are not prerequisites for coordinated transcription and accumulation. The majority of silkworm-specific miRNAs are located in transposable elements, and display significant differences in abundance between the anterior and posterior silk glands. Conclusions: Conservative analysis revealed that miRNAs serve as phylogenetic markers and function in evolutionary signaling. The newly identified miRNAs greatly enriched the repertoire of insect miRNAs, and provide insights into miRNA evolution, biogenesis, and expression in insects. The differential expression of miRNAs in the anterior and posterior silk glands supports their involvement as new layers in the regulation of the silkworm silk gland.