Project description:Phenotypic plasticity, the ability of one genotype to express different phenotypes in response to changing environmental conditions, is one of the most common phenomena characterising the living world and is not only relevant for the ecology but also for the evolution of species. Daphnia, the waterflea, is a textbook example for predator induced phenotypic plastic defences including changes in life-history, behaviour and morphology. However, the analysis of molecular mechanisms underlying these inducible defences is still in its early stages.<br><br>We exposed Daphnia magna to chemical cues of the predator Triops cancriformis to identify key processes underlying plastic defensive trait formation. D. magna is known to develop an array of morphological changes in the presence of T. cancriformis including changes of carapace morphology and cuticle hardening. To get a more comprehensive idea of this phenomenon, we studied four different genotypes originating from habitats with different predation history, reaching from predator-free to temporary habitats containing T. cancriformis.<br><br>We analysed the morphologies as well as proteomes of predator-exposed and control animals. Three genotypes showed morphological changes when the predator was present. Using a high-throughput proteomics approach, we found 294 proteins which were significantly altered in their abundance after predator exposure in a general or genotype dependant manner. Proteins connected to genotype dependant responses were related to the cuticle, protein synthesis and calcium binding whereas the yolk protein vitellogenin increased in abundance in all genotypes, indicating their involvement in a more general response. Furthermore, genotype dependant responses at the proteome level correlated well with local adaptation to Triops predation.<br><br>Altogether, our study provides new insights concerning genotype dependant and general molecular processes involved in predator-induced phenotypic plasticity in D. magna.
Project description:Antibody microarray based profiling of twelve urine samples.<br>3 healthy female<br>3 heatlhy male<br>3 female with pancreatic cancer<br>3 male with pancreatic cancer<br>
Project description:DNA binding profiling of endogenous HIF1A on proximal promoters in human HeLa cells exposed to 1% oxygen (hypoxia), using normoxic cells (21% oxygen) as reference.<br><br>Biological background: The Hypoxia Inducible Factor Family of transcription factors is proposed as the main orchestrator of the cellular response to hypoxia. HIFs are heterodimers of a HIF alpha and a HIF beta subunit. HIF alpha protein stability is regulated by oxygen-dependent proteasomal degradation, and hence HIFs are strongly stabilized in hypoxia.<br><br>Purpose of the study: a number of HIF1 ChIP-chip studies have been reported, employing various cell types, array platforms and HIF antibodies, and the overlap of HIF binding locations in these studies is relatively small. The aim of this study was to characterize HIF1 binding in an additional cell line (HeLa), and employing a different HIFalpha antibody.<br><br>Experimental design: We conducted a total of six hybridizations employing four biological replicates. For two biological replicates, we performed dye-swap technical replicate experiments.<br><br>Results summary: We identified 55 HIF binding locations in HeLa cells (FDR<2%). While this number is relatively low compared to previous studies, presumably due to limiting antibody sensitivity, the overlap with data from other cell lines is comparable to our HeLa data.
Project description:Within a study RNA samples of synovial fluid polymorphnuclear neutrophil granulocytes from 9 RA patients and of blood PMN from 4 healthy donors were analyzed for anti-apoptotic gene expression. The RNA samples were amplified and labelled red. Control samples (SigM5 cell culture) were labelled green. Each sample and control sample was co-hybrizated on a microarray with 780 inflammatory genes and 20 internal controls. Within the 19 anti-apoptotic genes tested, only the p21cip1waf1, CDKN1A, gene is significantly upregulated.
Project description:This study newly identified Tripelennamine (TA) as an inhibitor of yeast meiosis and sporulation. To examine if and how exposure of sporulating yeast cells to TA changes the meiotic transcriptional program cells were sporulated for 0, 4, and 8 hours in the presence or absence of 100 uM TA.
Project description:Gene expression analysis of S. coelicolor M145 wild type strain, and mutants delta0877 and delta 7173. RNA samples were extracted from 48 h culture samples during growth in flasks in defined mineral medium MG supplemented with 5% of yeast extract. Cy5 labelled genomic DNA was used as the common reference.
Project description:Gene expression profiling studies were performed at various times using a defined in vitro endothelial cell invasion assay system. Total RNA from invading cells was isolated at 0, 6, 12 and 18 hours and subjected to microarray analyses.
Project description:Leishmaniasis is an antropozoonosis caused by Leishmania parasites that affects around 12 million people in 98 different countries. The disease has different clinical forms, which depend mainly on the parasite genetics and on the immunologic status of the host. The promastigote form of the parasite is transmitted by an infected female phlebotomine sand fly, is internalized by phagocytic cells, mainly macrophages, and converts into amastigotes which replicate inside these cells. Macrophages are important cells of the immune system, capable of efficiently killing intracellular pathogens. However, Leishmania, can evade these mechanisms due to expression of virulence factors. Different strains of the same Leishmania species may have different infectivity and metastatic phenotypes in vivo. In the present work, we show that parasites from LV79 and PH8 strains have different lesion development in BALB/c and C57BL/6 mouse strains. The comparison of the proteomes of lesion-derived amastigotes from the two strains identified proteins such as CPx, SOD, HSP70 and GP63 as differentially expressed. The expression profile of all proteins and of the differentially expressed ones precisely classified PH8 and LV79 samples, indicating that the two strains are highly divergent and that protein expression correlate with their phenotypes.