Project description:Lead (Pb2+) is an environmental contaminant that is widely distributed around the world, mainly due to anthropogenic sources. Developmental exposure to Pb2+ has been linked to neurodevelopmental impairments in different animal species. Studies have shown that developmental exposure to Pb2+ could interfere with normal gene expression patterns in the immature brain leading to neurodevelopmental neuropathologies. However, the precise molecular mechanisms underlying the neurotoxicity of developmental Pb2+ exposure are still to be elucidated. We used the fruit fly to gain insights into the molecular mechanisms affected by exposure to this neurotoxicant. The fruit fly, has been used recently to understand the behavioral, synaptic and molecular changes after developmental exposure to Pb+2. Our overarching hypothesis is that developmental exposure of the fruit fly to Pb+2 results in global gene expression dysregulation in the larval brain resulting in central nervous system developmental impairments. We collected RNA samples from larval brain of control and Pb2+-exposed flies and performed cRNA hybridization on a 4x44K Agilent microarray. Overall, Pb+2 results in transcriptional disturbances of important developmental signaling pathways in the larval brain.
Project description:The goal was to study the effects of lead exposure on gene expression and identify the lead-responsive genes. After detecting 1,536 cis-eQTLs (FDR ⤠10%) and 952 trans-eQTLs, we focused our analysis on Pb-sensitive âtrans-eQTL hotspotsâ. 158 randomly selected Drosophila Synthetic Population Resource (A2) samples (control 79 samples and Pb-treated) without replicates
Project description:The innate immune response of insects relies on several humoral and cellular mechanisms that require the activation of circulating proteases in the hemolymph to be functional. Here, we analyzed the gelatinase and caseinase activities of Drosophila larval hemolymph under normal and pathogenic conditions (bacterial lipopolysaccharides or endoparasitoid Leptopilina boulardi) using in gel zymography. Gelatinase activity was more intense than caseinase activity and qualitative and quantitative variations were observed between D. melanogaster strains and Drosophila species. Mass spectrometry identified a large number of serine proteases in gel bands equivalent to the major gelatinase and caseinase bands and of these, the most abundant and redundant were Tequila and members of the Jonah and Trypsin protease families. However, hemolymph from Tequila null mutant larvae showed no obvious changes in zymographic bands. Nor did we observe any significant changes in hemolymph gelatinases activity 24 h after injection of bacterial lipopolysaccharides or after oviposition by endoparasitoid wasps. These data confirmed that many serine proteases are present in Drosophila larval hemolymph but those with gelatinase and caseinase activity may not change drastically during the immune response.
Project description:In Drosophila melanogaster larval hemolymph, under normal conditions, plasmatocytes and crystal cells represent respectively ~95% and ~5% of hemocytes, while lamellocytes, the third larval cell type, are absent since they are only induced after parasitoid wasp oviposition, their role being the encapsulation-melanization response to eliminate the wasp egg. However, even after induction lamellocytes number remains low, making difficult biochemical studies. Here using the D. melanogaster hopTum-l mutant that constitutively produces a high number of hemocytes, we set up a method to purify lamellocytes and analyzed their major proteins by 2D gel electrophoresis and their biotinylated plasma membrane surface proteins by 1D SDS-PAGE after affinity purification. Mass spectrometry allowed to identify 430 proteins from the 2D spots and 344 from affinity purified proteins, totalizing 639 unique proteins. Known lamellocyte markers such as PPO3 and the integrin myospheroid are among the major proteins and affinity purification led to the detection of other integrins and a large array of integrins associated proteins involved in cell-cell junction formation and function. Overall newly identified proteins indicated that these cells are highly adapted to the encapsulation process but may have also several different physiological functions. This study provides the basis for new lamellocyte studies in vivo and in vitro, and develop markers to search whether different populations coexist, establish their origins and decipher their respective roles in drosophila physiology and immunity.
Project description:microRNAs (miRNAs) are a class of small non-coding RNAs involved in the coordination and/or fine-tuning of gene expression. As such, miRNAs are thought to be critical cis-acting regulatory factors that control a wide range of physiological processes in the brain. The datasets presented here represent the miRNA transcriptome of the adult and larval Drosophila melanogaster CNS as determined by small RNA deep sequencing (RNA-Seq). They were derived from adult and larval samples explanted from the animal that contain minimal extraneous (non-neuronal) tissues. Here we present a concise summary of our profiling results as well as the original sequencing data. We identify many miRNAs that are expressed at equal levels in both tissues and several that are significantly enriched in the larval and adult brain. Some of these belong to miRNA families with conserved members in mammals. These datasets should provide a good starting point for others interested in characterizing miRNAs with putative functions in Drosophila neurons. The datasets presented here represent the miRNA transcriptome of the adult and larval Drosophila melanogaster CNS as determined by small RNA deep sequencing (RNA-Seq).
Project description:Aim: Su(H) chromatin occupancy profiling by ChIP on larval wing imaginal discs of Drosophila melanogaster to study the cooperation between Notch activation and loss of epithelial polarity (scrib mutation) during neoplastic growth. Results: The combination of Notch activation and scribble mutation (NS) does not lead to a general redeployment of Su(H) binding as compared to individual conditions (Notch only (N), and scrib mutation only (S))