Project description:Genes with sex-biased expression in adults experience unique evolutionary dynamics. It is unclear, however, whether the selection pressures responsible for these well documented patterns also act upon genes with sex-biased expression in other developmental stages. To examine this, we measured expression in male and female Drosophila melanogaster larvae.
Project description:Nucleus is a highly structured organelle and contains many functional compartments. While the structural basis for this complex spatial organization of compartments is unknown, a major component of this organization is likely to be the non-chromatin scaffolding called nuclear matrix (NuMat). Experimental evidence over the past decades indicates that most of the nuclear functions are at least transiently associated with the NuMat although the components of NuMat itself are poorly known. Here, we report NuMat proteome analysis from Drosophila melanogaster embryos and discuss its links with nuclear architecture and functions. In the NuMat proteome, we find structural proteins, chaperones related, DNA/RNA binding, chromatin remodeling and transcription factors. This complexity of NuMat proteome is an indicator of its structural and functional significance. Comparison of the 2D profile of NuMat proteome from different developmental stages of Drosophila embryos shows that less than half of the NuMat proteome is constant and rest of the proteins are stage specific dynamic components. This NuMat dynamics suggests a possible functional link between NuMat and the embryonic development. Finally, we also show that a subset of NuMat proteins remain associated with the mitotic chromosomes implicating their role in mitosis and possibly the epigenetic cellular memory. NuMat proteome analysis provides tools and opens up ways to understand nuclear organization and function.
Project description:Genes with sex-biased expression in adults experience unique evolutionary dynamics. It is unclear, however, whether the selection pressures responsible for these well documented patterns also act upon genes with sex-biased expression in other developmental stages. To examine this, we measured expression in male and female Drosophila melanogaster larvae. Drosophila melanogaster wandering third instar larvae were sexed using the visible gonad. RNA was isolated from three replicate samples of male and female larvae and one sample each of adult males and females. RNA was prepared following the manufacturer's instructions, using single color labelling. Each sample/replicate was hybridized to one sector of the Agilent 4 sector array (a total of two arrays were used), with the following design: Array 1 had one larval male sample, one larval female sample, one adult male sample, and one adult female sample; Array 2 had two larval male samples and two larval female samples.
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:Experimental evolution was conducted using Drosophila melanogaster populations that developed as larvae on breeding substrate that was infested with Aspergillus nidulans wild type, A. nidulans toxin-impaired mutant strain delta-laeA, the mycotoxin sterigmatocystin, or on fungi and toxin free substrate. Overall population were reared under these conditions for 11 generations, where after each confrontation generation one relaxation generation (fungi and toxin free breeding substrate) was conducted. Nine generations after the last selection treatment, first instar larvae were confronted with 3 days old A. nidulans wild type colonies or control conditions. 24 hours after confrontation start larvae were collected. For each biological replicate 52 larvae were collected from 4 independent confrontation units, balanced design. Three populations per selection regime were conducted, resulting in: 2 conditions x 4 selection regimes x 3 biological replicates (equal to fly population) = 24 samples. Selection regimes: sCO= control; sWT= A. nidulans wild type; sLA= A. nidulans mutant strain; sST= Sterigmatocystin. confrontation condition: cCO= control; cWT= A. nidulans wild type.