Project description:Insect cuticle plays essential roles in multiple physiological functions. During molting and metamorphosis, tremendous changes occur in silkworm cuticles. Silkworm is a model of Lepidoptera insects; however, little is known about the stage expression profiles of genes in cuticles of silkworm. In the present study, we selected 16 developmental stages, ranging from day 1 of the first instar larvae to day 8 of pupae, to perform microarray-based expression profiles. The data told us that various functions and physiological pathways were activated in the cuticle. Moreover, the expression profiles of cuticular protein genes, as the important components of cuticle, were investigated. The current study provides important insights for the functional study of insect cuticle and the regulation of insect cuticular protein genes.
Project description:Insect cuticle plays essential roles in multiple physiological functions. During molting and metamorphosis, tremendous changes occur in silkworm cuticles. Silkworm is a model of Lepidoptera insects; however, little is known about the stage expression profiles of genes in cuticles of silkworm. In the present study, we selected 16 developmental stages, ranging from day 1 of the first instar larvae to day 8 of pupae, to perform microarray-based expression profiles. The data told us that various functions and physiological pathways were activated in the cuticle. Moreover, the expression profiles of cuticular protein genes, as the important components of cuticle, were investigated. The current study provides important insights for the functional study of insect cuticle and the regulation of insect cuticular protein genes. Transcription profiling experiments, 16 developmental stages (samples) were analyzed. Dual-channel experiments, with test samples labeled by Cy5 and common reference samples labeled by Cy3. Common reference sample was used for data normalization. One biological replicate. No dye-swaps.
Project description:Background: The growth and development of the posterior silk gland and the biosynthesis of the silk core protein at the fifth larval instar stage of Bombyx mori are of paramount importance for silk production. Results: Here, aided by next-generation sequencing and microarry assay, we profile 1,229 microRNAs (miRNAs), including 728 novel miRNAs and 110 miRNA/miRNA* duplexes, from the posterior silk gland at the fifth larval instar. Target gene prediction yields 14,222 unique target genes from 1,195 miRNAs. Functional categorization classifies the genes into complex pathways that include both cellular and metabolic processes, especially protein synthesis and processing. Conclusion: The enrichment of target genes in the ribosome-related pathway indicates that miRNAs may directly regulate translation. Our findings pave a way for further functional elucidation of these miRNAs in silk production. Sequencing 10 total RNA samples from the posterior silk gland of different strains and developmental stage using Illumina Solexa technology. Four strains of silkworm (Q, B, QB and BQ) with different two development stages (stage 1: fourth instar molting to day 2 of fifth instar; stage 2: fifth instar day 3 to day 8 before spinning, according to our previous genes expression cluster analysis), and two strains (R1 and J1) from entire period (stage 1 + stage 2).
Project description:Background: MicroRNAs (miRNAs) repress target genes at the post-transcriptional level, and function in the development and cell-lineage pathways of host species. Tissue-specific expression of miRNAs is highly relevant to their physiological roles in the corresponding tissues. However, to date, few miRNAs have been spatially identified in the silkworm. Results: We establish for the first time the spatial expression patterns of nearly 100 miRNAs in multiple normal tissues (organs) of Bombyx mori females and males using microarray and Northern-blotting analyses. In total, only 10 miRNAs were universally distributed (including bmo-let-7 and bmo-bantam), while the majority were expressed exclusively or preferentially in specific tissue types (e.g. bmo-miR-275 and bmo-miR-1). We additionally examined the developmental patterns of miRNA expression during metamorphosis of the body wall, silk glands, midgut and fat body. In total, 63 miRNAs displayed significant alterations in abundance in at least 1 tissue during the developmental transition from larvae to pupae (e.g. bmo-miR-263b and bmo-miR-124). Expression patterns of five miRNAs were significantly increased during metamorphosis in all four tissues (e.g. bmo-miR-27 and bmo-miR-305). Conclusions: In this study, we conducted preliminary spatial measurements of several miRNAs in the silkworm. Periods of rapid morphological change were associated with alterations in miRNA expression patterns in the body wall, silk glands, midgut and fat body during metamorphosis. Accordingly, we propose that this ubiquitous or tissue-specific expression of miRNAs supports their critical roles in tissue specification. The results obtained should facilitate future functional analyses. To determine the global spatial expression patterns of miRNAs in silkworm, we designed a DNA oligonucleotide-based microarray examining 92 unique miRNAs with 106 antisense probes. To determine the extent of tissue-specific changes during the specific developmental events, we assessed changes in miRNA expression in four individual tissues and organs (body wall, silk glands, midgut and fat body) from the larval to pupal stages.
Project description:Background: MicroRNAs (miRNAs) repress target genes at the post-transcriptional level, and function in the development and cell-lineage pathways of host species. Tissue-specific expression of miRNAs is highly relevant to their physiological roles in the corresponding tissues. However, to date, few miRNAs have been spatially identified in the silkworm. Results: We establish for the first time the spatial expression patterns of nearly 100 miRNAs in multiple normal tissues (organs) of Bombyx mori females and males using microarray and Northern-blotting analyses. In total, only 10 miRNAs were universally distributed (including bmo-let-7 and bmo-bantam), while the majority were expressed exclusively or preferentially in specific tissue types (e.g. bmo-miR-275 and bmo-miR-1). We additionally examined the developmental patterns of miRNA expression during metamorphosis of the body wall, silk glands, midgut and fat body. In total, 63 miRNAs displayed significant alterations in abundance in at least 1 tissue during the developmental transition from larvae to pupae (e.g. bmo-miR-263b and bmo-miR-124). Expression patterns of five miRNAs were significantly increased during metamorphosis in all four tissues (e.g. bmo-miR-27 and bmo-miR-305). Conclusions: In this study, we conducted preliminary spatial measurements of several miRNAs in the silkworm. Periods of rapid morphological change were associated with alterations in miRNA expression patterns in the body wall, silk glands, midgut and fat body during metamorphosis. Accordingly, we propose that this ubiquitous or tissue-specific expression of miRNAs supports their critical roles in tissue specification. The results obtained should facilitate future functional analyses.