Project description:In the present study, the silk gland proteomes of the fourth instar and fourth molt were analyzed using liquid chromatography−tandem mass spectrometry. In total, 2654 proteins were identified from the silk gland. High abundance of ribosomal proteins and RR-motif chitin-binding proteins were identified during day 2 of the fourth instar (IV-2) larval developmental stage, and the expression of cuticular proteins analogous to peritrophin (CPAP)-motif chitin-binding proteins was higher during the fourth molt (IV-M). In all, nine enzymes were found to be involved in the chitin regeneration pathway in the silk gland. Among them, two chitinase and two chitin deacetylases were identified as CPAP-motif proteins.
Project description:The present work is the pioneering report depicting the total proteomic atlas of four major developmental stages (third, fourth, fifth instar and pupa) of M. vitrata by LC-MS/MS analyses.
Project description:High-throughput sequencing of Drosophila melanogaster small RNAs. Total RNA, ~18-26nt RNAs isolated using PAGE, ligation to adapters requires 5' monophosphate and 3' OH For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Small RNAs were sequenced from D. melanogaster (Canton S) wandering late embryos, first instar larvae, third instar larvae or from 2-4 day old pupae and adult female heads or male heads. Raw sequences were clipped by 3' linker sequences recognition, and select clipped sequences longer than 18 nt.
Project description:Phytophagous insects use volatile organic compounds (VOC) emitted by plants to orient towards their hosts. In lepidopteran pests, crop damages are caused by larval stages-the caterpillars-that feed extensively on leaves or other plant tissues. However, larval host plant choice has been poorly studied, and it is generally admitted that caterpillars feed on the plant where the female laid the eggs. The mobility of caterpillars has been generally overlooked even though several studies showed that they can orient towards odors and change host plant. Recently, a large number of odorant receptors (ORs) tuned to plant volatiles have been characterized in the model pest moth Spodoptera littoralis (Noctuidae). In the present work, we identified nine of these deorphanized ORs as expressed in S. littoralis caterpillars. In order to understand whether these ORs are involved in host searching, we tested the behavioral significance of their ligands using a larval two-choice assay. This OR-guided approach led to the identification of nine plant volatiles, namely 1-hexanol, benzyl alcohol, acetophenone, benzaldehyde, (Z)3-hexenol, (E)2-hexenol, indole, DMNT and (Z)3-hexenyl acetate, which are active on S. littoralis caterpillar behavior, increasing our knowledge on larval olfactory abilities. To further explore the link between OR activation and behavioral output induced by plant volatiles we used a modeling approach, thereby allowing identification of some ORs whose activation is related to caterpillar attraction. These ORs may be promising targets for future plant protection strategies.
Project description:The cellular composition of the brain and how it is affected by starvation, remains largely unknown. Here we introduce a single-cell transcriptome atlas of the entire Drosophila melanogaster first instar larval brain. We first assigned cell type identity based on the expression of previously characterized marker genes, allowing us to distinguish five major groups: neural progenitors cells, differentiated neurons, glial cells, undifferentiated neurons as well as non-neural cells corresponding to organs and structures located adjacent to the brain. All major classes were further subdivided into multiple subtypes based on cluster analysis, revealing critical biological features of various cell types. Moreover, we included two different feeding conditions: normal fed versus starved. After starvation, the transcriptional profile of several cell clusters were altered, while the overall composition of the brain remains unaffected. Intriguingly, different cell clusters show very distinct responses to starvation, suggesting the presence of cell-specific programs for nutrition availability. Establishing a single-cell transcriptome atlas of the larval brain provides a powerful tool to explore cell diversity, assess genetic profiles of neurogenic, neuronal and glial cell types. The analysis of neurotransmitters, neuropeptides and their respective receptors may further open the doors for functional studies.
2019-11-15 | GSE134722 | GEO
Project description:First and fourth instars Spodoptera littoralis larval transcriptome
Project description:The lymph gland is one of the main larval hematopoietic organin in Drosophila melanogaster. In wnandering third instar larav, it is composed of two pairs of anterior lobes, followed by 2 to 3 pair of posterior lobes. To gain further insight into the gene expression repertoire of Drosophila blood cells, we established the gene expression profiles of third instar larva lymph glands anterior and posterior lobes.
Project description:The silkworm silk gland is one of the most efficient protein synthesis systems among all organisms. Its amazingly efficient protein synthesis makes the silk gland a desirable object for basic studies on gene expression and regulation and for biotechnological applications. At the early stages of the fifth (final) instar, the cellular structures necessary for the synthesis of fibroin are rapidly formed, and at the later stage the synthesis of fibroin proceeds at a maximum rate. The posterior silk gland (PSG) is the longest suborgan and is responsible for the synthesis of the silk core protein fibroin, which is composed of heavy (H) and light (L) chains plus P25. We used microarrays to detail the global programme of gene expression in silkworm PSG during the late larval stages, including the fourth molting (M4) and day 1 (V1), day 3 (V3), day 5 (V5), and day 7 (wandering stage, W) of the fifth instar, and to reveal the correlations of differential expression genes with the PSG development and fibroin synthesis.