Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
Project description:Ablation of the Creb1 gene in forebrain neurons was performed using the Cre/loxP system, with the recombinase expressed from the Camk2alfa promoter. Mice were crossed into the Crem KO background to prevent compensation of CREB loss by CREM overexpression. Our goal was to analyze how loss of CREB will affect acitivity-regulated transcription induced by strong stimulation, i.e. kainate. Experiment Overall Design: Animals were injected i.p. with either 20 mg/kg kainate or saline and sacrificed after one hour by cervical dislocation. Expression profiling was performed using total RNA isolated from the hippocampus.
Project description:Ablation of the Creb1 gene in forebrain neurons was performed using the Cre/loxP system, with the recombinase expressed from the Camk2alfa promoter. Mice were crossed into the Crem KO background to prevent compensation of CREB loss by CREM overexpression. Our goal was to analyze how loss of CREB will affect acitivity-regulated transcription induced by strong stimulation, i.e. kainate. Experiment Overall Design: Animals were injected i.p. with either 20 mg/kg kainate or saline and sacrificed after one hour by cervical dislocation. Expression profiling was performed using total RNA isolated from the hippocampus.
Project description:Ablation of the Creb1 gene in forebrain neurons was performed using the Cre/loxP system, with the recombinase expressed from the Camk2alfa promoter. Mice were crossed into the Crem KO background to prevent compensation of CREB loss by CREM overexpression. Our goal was to analyze how loss of CREB will affect acitivity-regulated transcription induced by strong stimulation, i.e. kainate. Experiment Overall Design: Animals were injected i.p. with either 20 mg/kg kainate or saline and sacrificed after one hour by cervical dislocation. Expression profiling was performed using total RNA isolated from the hippocampus.
Project description:Although early developmental processes involve cell fate decisions that define the body axes and establish progenitor cell pools, development does not cease once cells are specified. Instead, most cells undergo specific maturation events where changes in the cell transcriptome ensure that the proper gene products are expressed to carry out unique physiological functions. Pancreatic acinar cells mature post-natally to handle an extensive protein synthetic load, establsih organized apical-basal polarity for zymogen granule trafficking, and assemble gap-junctions to perimt efficient cell-cell communication. Despite significant progress in defining transcriptional networks that control initial acinar cell specification and differentiation decisions, little is know regarding the role of transcription factors in the specification and maintenance of maturation events. One candidate maturation effector is MIST1, a secretory cell-restricted transcription factor that has been implicated in controlling regulated exocytosis events in a number of cell types. Embryonic knock-out of MIST1 generates acinar cells that fail to establish an apical-basal organization, fail to properly localize zymogen granule and fail to communicate intra-cellularly, making the exocrine organ highly suceptible to pancreatic diseases. In an effort to identify the gene expression differences responsible for MIST1 regulating mature acinar properties. We generated a tamoxifen-inducible mouse model where MIST1 expression could be activated in vivoand performed gene expression arrays on wildtype, MIST1-null, and induced MIST1 pancreatic RNA.
Project description:The cAMP responsive element binding protein (CREB) pathway has been involved in two major cascades of gene expression regulating neuronal function. The first one presents CREB as a critical component of the molecular switch that control longlasting forms of neuronal plasticity and learning. The second one relates CREB to neuronal survival and protection. To investigate the role of CREB-dependent gene expression in neuronal plasticity and survival in vivo, we generated bitransgenic mice expressing A-CREB, an artificial peptide with strong and broad inhibitory effect on the CREB family, in forebrain neurons in a regulatable manner. The expression of ACREB in hippocampal neurons impaired L-LTP, reduced intrinsic excitability and the susceptibility to induced seizures, and altered both basal and activity-driven gene expression. In the long-term, the chronic inhibition of CREB function caused severe loss of neurons in the CA1 subfield as well as in other brain regions. Our experiments confirmed previous findings in CREB deficient mutants and revealed new aspects of CREB-dependent gene expression in the hippocampus supporting a dual role for CREB-dependent gene expression regulating intrinsic and synaptic plasticity and promoting neuronal survival. manufacturer's protocol. Experiment Overall Design: Each sample contained total RNA from the hippocampi of a group of 3-4 three weeks old mice. We obtained duplicate samples for each experimental condition (in total 14 WT and 20 A-CREB mice where used in this experiment). Mouse Genome 430 2.0 genechips were hybridized, stained, washed and screened for quality according to the manufacturer's protocol.