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:To examine the Ten-Eleven Translocation (TET) proteins and their role in tumorigenesis in hemocytes and heads in Drosophila melanogaster. To identify the transcriptomic profile of wild type mTET2 versus mTET2 mutants (catalytic versus non-catalytic) to investigate TET2 role in normal central nervous system (CNS) function and innate immunity.
Project description:Thermal acclimation study on Drosophila melanogaster reared at 3 different temperatures (12, 25, and 31oC). The proteomic profiles of D. melanogaster under these different temperatures were analyzed and compared using label-free tandem mass spectrometry.
Project description:Feeding resveratrol to Drosophila melanogaster extends lifespan. Studies of microarray show similarities between calorie/dietary restriction and resveratrol on both a gene expression and biological pathway level. 9 samples: 3 biological replicates each of normal diet, restricted diet and normal diet plus resveratrol
Project description:Long-term consumption of fatty foods is associated with obesity, macrophage activation and inflammation, metabolic imbalance, and a reduced lifespan. We took advantage of Drosophila genetics to investigate the role of macrophages and the pathway(s) that govern their response to dietary stress. Flies fed a lipid-rich diet presented with increased fat storage, systemic JAK-STAT activation, reduced insulin sensitivity and hyperglycaemia, and a shorter lifespan. Drosophila macrophages scavenged lipids and produced the type 1 cytokine upd3, in a scavenger-receptor (croquemort) and JNK-dependent manner. Genetic depletion of macrophages, or macrophage-specific silencing of upd3 decreased JAK-STAT activation and rescued insulin sensitivity and the lifespan of Drosophila, but did not decrease fat storage. NF-M-NM-:B signalling made no contribution to the phenotype observed. These results identify an evolutionarily conserved M-bM-^@M-^Xscavenger receptor-JNK-Type 1 cytokineM-bM-^@M-^Y cassette in macrophages, which controls glucose metabolism and reduces lifespan in Drosophila maintained on a lipid-rich diet via activation of the JAK-STAT pathway Long-term consumption of fatty foods is associated with obesity, macrophage activation and inflammation, metabolic imbalance, and a reduced lifespan. We took advantage of Drosophila genetics to investigate the role of macrophages and the pathway(s) that govern their response to dietary stress. Flies fed a lipid-rich diet presented with increased fat storage, systemic JAK-STAT activation, reduced insulin sensitivity and hyperglycaemia, and a shorter lifespan. Drosophila macrophages scavenged lipids and produced the type 1 cytokine upd3, in a scavenger-receptor (croquemort) and JNK-dependent manner. Genetic depletion of macrophages, or macrophage-specific silencing of upd3 decreased JAK-STAT activation and rescued insulin sensitivity and the lifespan of Drosophila, but did not decrease fat storage. NF-M-NM-:B signalling made no contribution to the phenotype observed. These results identify an evolutionarily conserved M-bM-^@M-^Xscavenger receptor-JNK-Type 1 cytokineM-bM-^@M-^Y cassette in macrophages, which controls glucose metabolism and reduces lifespan in Drosophila maintained on a lipid-rich diet via activation of the JAK-STAT pathway 5 biological samples were FACS-sorted from different batches of Drosophila melanogaster males after 30 days on 15% lipid enriched diet (n=5) and control diet (n=5)
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.