Ribosome biogenesis requires equimolar amounts of four rRNAs and all 79 ribosomal proteins (RP). Coordinated regulation of rRNA and RP synthesis by eukaryotic RNA polymerases (Pol) I, III, and II is a key requirement for growth control. Using a novel global genetic approach, we showed that the absence of Hmo1 becomes lethal when combined with mutations of components of either the RNA Pol II or Pol I transcription machineries, of specific RP, or of the TOR pathway. Hmo1 directly interacts with bo ...[more]
Project description:This work aimed at analysing mRNA half lives in drug resistant and in drug sensitive strains of C. albicans (Gu4 and Gu5 azole susceptible and resistant clinical isolates (franz et al., 1999)), using the transcriptional inhibitor thiolutine.
Project description:This work aimed at analysing the transcriptome response of S. cerevisiae strains, wild type or deleted for transcription factor encoding genes involved in stress response, to selenite (1mM), inoculated for different time periods.
Project description:This work aimed at analysing the transcriptome response of S. cerevisiae and C. albicans strains, wild type or deleted for transcription factor encoding genes involved in pleiotropic drug resistance, to three different doses of progesterone, inoculated for three different time periods.
Project description:Mating is a complex process that causes many behavioral and physiological changes, but the factors triggering these changes and the underlying molecular processes are not well characterized. Honey bee queens provide a convenient system for dissecting these factors (e.g., physical manipulation, insemination volume, insemination substance) via instrumental insemination. We examined the effects of carbon dioxide (CO2), a commonly used anesthetic in instrumental insemination that causes changes similar to those observed after mating, and physical manipulation, which presumably mimics the act of copulation, on the brain transcriptional changes in honey bee queens. We found significant gene overlap between our study and previous mating studies in honey bee queens and Drosophila. This suggests that molecular pathways regulating the mating process are conserved across different mating regimes of honey bees as well as across insect orders.
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:Newly emerged adult workers (24 hours old) were infected with 50,000 Nosema apis spores in sucrose solution. Controls were fed sucrose. Workers were maintained in cages in an incubator and collected at 2 and 7 days post-infection. Fat body tissue was dissected (eviscerated abdomen) and whole genome expression in this tissue was compared across treatments and collection time points using microarrays.