Project description:Background: MicroRNAs (miRNAs) are expressed by a wide range of eukaryotic organisms, and function in diverse biological processes. Numerous miRNAs have been identified in Bombyx mori, but the temporal expression profiles of miRNAs corresponding to each stage transition over the entire life cycle of the silkworm remain to be established. To obtain a comprehensive overview of the correlation between miRNA expression and stage transitions, we performed a whole-life test and subsequent stage-by-stage examinations on nearly one hundred miRNAs in the silkworm. Results: Our results show that miRNAs display a wide variety of expression profiles over the whole life of the silkworm, including continuous expression from embryo to adult (bmo-miR-184), up-regulation over the entire life cycle (bmo-let-7 and miR-100), down-regulation over the entire life cycle (miR-124), expression associated with embryogenesis (miR-29 and miR-92), up-regulation from early 3rd instar to pupa (miR-275), and complementary pulses in expression between miR-34b and miR-275. Stage-by-stage examinations revealed further expression patterns, such as emergence at specific time-points during embryogenesis and up-regulation of miRNA groups in late embryos (miR-1 and bantam), expression associated with stage transition between instar and molt larval stages (miR-34b), expression associated with silk gland growth and spinning activity (miR-274), continuous high expression from the spinning larval to pupal and adult stages (miR-252 and miR-31a), a coordinate expression trough in day 3 pupae of both sexes (miR-10b and miR-281), up-regulation in pupal metamorphosis of both sexes (miR-29b), and down-regulation in pupal metamorphosis of both sexes (miR-275). Conclusions: We present the full-scale expression profiles of miRNAs throughout the life cycle of Bombyx mori. The whole-life expression profile was further investigated via stage-by-stage analysis. Our data provide an important resource for more detailed functional analysis of miRNAs in this animal. In the study presented here, we performed a whole-life test and subsequent stage-by-stage examinations on nearly one hundred miRNAs in the silkworm, leading to a comprehensive overview of the correlation between miRNA expression and stage transitions. In all, 59 unique developmental timepoints were inspected in this study.
Project description:Background: MicroRNAs (miRNAs) are expressed by a wide range of eukaryotic organisms, and function in diverse biological processes. Numerous miRNAs have been identified in Bombyx mori, but the temporal expression profiles of miRNAs corresponding to each stage transition over the entire life cycle of the silkworm remain to be established. To obtain a comprehensive overview of the correlation between miRNA expression and stage transitions, we performed a whole-life test and subsequent stage-by-stage examinations on nearly one hundred miRNAs in the silkworm. Results: Our results show that miRNAs display a wide variety of expression profiles over the whole life of the silkworm, including continuous expression from embryo to adult (bmo-miR-184), up-regulation over the entire life cycle (bmo-let-7 and miR-100), down-regulation over the entire life cycle (miR-124), expression associated with embryogenesis (miR-29 and miR-92), up-regulation from early 3rd instar to pupa (miR-275), and complementary pulses in expression between miR-34b and miR-275. Stage-by-stage examinations revealed further expression patterns, such as emergence at specific time-points during embryogenesis and up-regulation of miRNA groups in late embryos (miR-1 and bantam), expression associated with stage transition between instar and molt larval stages (miR-34b), expression associated with silk gland growth and spinning activity (miR-274), continuous high expression from the spinning larval to pupal and adult stages (miR-252 and miR-31a), a coordinate expression trough in day 3 pupae of both sexes (miR-10b and miR-281), up-regulation in pupal metamorphosis of both sexes (miR-29b), and down-regulation in pupal metamorphosis of both sexes (miR-275). Conclusions: We present the full-scale expression profiles of miRNAs throughout the life cycle of Bombyx mori. The whole-life expression profile was further investigated via stage-by-stage analysis. Our data provide an important resource for more detailed functional analysis of miRNAs in this animal.
Project description:We identified genes regulated by parasitization of the silkworm Bombyx mori by three tachinid parasitoid species, Exorista japonica, Drino inconspicuoides and Pales pavida, using oligonucleotide microarrays. The numbers of genes and their intensity of expression varied with the species of parasitoid, within silkworm hemocytes and fat body. Bombyx mori hemocyte, silkgland and fat body samples parasitizated by Exorista japonica, Drino inconspicuoides and Pales pavida were prepared. Gene expression was compared in these two groups: control and parasitized.
Project description:We identified genes regulated by parasitization of the silkworm Bombyx mori by three tachinid parasitoid species, Exorista japonica, Drino inconspicuoides and Pales pavida, using oligonucleotide microarrays. The numbers of genes and their intensity of expression varied with the species of parasitoid, within silkworm hemocytes and fat body.
Project description:Uric acid (UA) is the final product of purine metabolism and plays an important role as a physiological antioxidant. In recent years, several different groups have reported a correlation between decreased UA in Parkinson’s disease (PD) and clinical progression and stage of PD. However, little is known about the molecular mechanisms of decreased UA under oxidative stress. We used our systematic functional annotation pipeline for silkworm genes to identify a novel UA metabolic pathway regulator under oxidative stress in a UA metabolism mutant silkworm Bombyx mori model. Gene expression was measured in 3day of fifth instar larvae of abnormal uric acid synthesis Bombyx mori mutant of op.
Project description:Maternal genes present in mature oocytes and play a crucial role in the early development of the silkworm. Although maternal genes have been widely studied in many species, there are limited research in Bombyx mori. High-through experimental technology provides a practical way for genome-wide study. Here we show a transcriptome study on silkworm eggs. Unfertilized eggs from five different stages of early development were used for detecting the change situation of gene expression. The expressed genes showed different patterns over time. Maternal genes were annotated according to homology analysis with Drosophila melanogaster. In our result, more than a half expressed maternal genes were fall into four expression patterns and showed downward trend over time. The function annotation of material genes showed that they were related to transcription factor activity, growth factor activity, nucleic acid binding, RNA binding, ATP binding, ion binding and so on. In additional, twenty-two gene clusters including material genes were identified from 18 scaffolds. Altogether, we plotted a profile for maternal genes of Bombyx mori using digital gene expression profiling method. It will provide a base for mother-specific signature research and improve the understanding of early development of silkworm.
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.
Project description:Uric acid (UA) is the final product of purine metabolism and plays an important role as a physiological antioxidant. In recent years, several different groups have reported a correlation between decreased UA in Parkinson’s disease (PD) and clinical progression and stage of PD. However, little is known about the molecular mechanisms of decreased UA under oxidative stress. We used our systematic functional annotation pipeline for silkworm genes to identify a novel UA metabolic pathway regulator under oxidative stress in a UA metabolism mutant silkworm Bombyx mori model.