Project description:RctR encodes a protein belonging to the GntR family of transcriptional regulators and is involved in regulation of conjugative transfer of symbiotic plasmids of Sinorhizobium meliloti. In order to identify genes differentially expressed in a 1021RctR mutant, the transcriptome of S. meliloti 1021RctR was compared with that of the wild-type 1021, using Sm6kOligo DNA microarrays. Cells of 1021 and 1021RctR were grown at 30C in TY broth to mid logarothmic phase (OD600nm)=0.7-0.8 before RNA isolation.
Project description:Hfq-dependent transcriptional alterations in the nitrogen-fixing endosymbiont S. meliloti. Comparison: S. meliloti 1021 strain Vs S. meliloti 1021Dhfq (containing a deletion of the hfq ORF).
Project description:S. meliloti 1021FDC5 was grown at 30ºC in 20 ml of TY broth with shaking to late logarithmic phase (optical density at 600 nm = 1-1.2). After incubation, cells were pelleted, washed twice in MM and resuspended in 2 ml of the latter medium. For time course experiments in liquid, 0.5 ml of the inoculation culture was added to 50 ml of fresh MM. At various times, samples were removed for determining viable cells counts as well as for RNA isolation/preparation (7 and 14 hours). For experiments on plates, 20 ml of MM containing 0.7% (Semisolid) or 1.3% (Solid) agar was dispensed onto each Petri dish and allowed to gel. The plates were air dried at room temperature for 15 min. 0.1 ml of the inoculation culture was plated onto the surface of the plates and allowed to dry for 10 min. The plates were then inverted and incubated at 30ºC.
Project description:This experiment captures the genes differentially expressed of the Sinorhizobium meliloti reference strain (Rm1021) when this bacteria is grown in semisolid media (MM 0.6%) in presence of a compound which promotes surface motiliy
Project description:Transcriptome profiling by array of the Sinorhizobium meliloti GR4-derivative mutant GNS577, affected in ntrY and ntrX genes, to identify possible cell processes regulated by this system
Project description:Responses to social cues, such as pheromones, can be modified by genotype, physiology, or environmental context. Honey bee queens produce a pheromone (queen mandibular pheromone; QMP) which regulates many aspects of worker bee behavior and physiology. Forager honey bees are less responsive to QMP than young nurse bees engaged in brood care, suggesting that physiological changes associated with behavioral maturation may modulate response to this pheromone. Since cGMP is a major regulator of behavioral maturation in honey bee workers, we examined its role in modulating worker responses to QMP. Treatment with a cGMP analog, 8-Br-cGMP, resulted in significant reductions in both behavioral and physiological responses to QMP in young caged workers. Treatment significantly reduced attraction to QMP (the retinue response) and inhibited the QMP-mediated increase in vitellogenin levels in the fat bodies of worker bees. Genome-wide analysis of brain gene expression patterns demonstrated that cGMP has a larger effect on expression levels than QMP, and that QMP has specific effects in the presence of cGMP, suggesting that some responses to QMP may be dependent on an individual bees physiological state. Several functional gene categories were significantly differentially expressed, including genes involved in regulating GTPase activity, phototransduction, immunity, and carboxylic acid transmembrane transporter activity. Overall, our data suggest that cGMP-mediated processes play a large role in modulating responses to queen pheromone in honey bees, at the behavioral, physiological and molecular levels.
Project description:Control experiment to confirm ligand independent effect on gene regulation by ERb in HT29 cells. The colon cancer cell lines do not express endogenous ER but is made ERb-expressing by lentiviral transduction of an ERb expression cassette. Introduction of ERb makes it possible to study the role and function of ERb in colon cancer as well as the impact ERb has on its own (in the absence of ERa).
Project description:Newly emerged adult workers (24 hours old) were infected with 25,000 Nosema apis spores and 25,000 Nosema ceranae spores in sucrose solution. Controls were fed sucrose. Workers were maintained in cages in an incubator and collected at 14 days post-infection. Fat bodies (eviscerated abdomens) were dissected and whole genome expression in this tissue was compared across treatments using microarrays.