Project description:Ethanol is a well-known teratogen. While this teratogenic potential is well-characterized clinically, the mechanisms through which ethanol exposure results in developmental defects remain unclear. Here we use the zebrafish model to elucidate eye-specific mechanisms that may underlie ethanol-mediated microphthalmia (reduced eye size), using time-series microarray analysis of gene expression of eye tissues of embryos exposed to 1.5% ethanol vs. untreated embryos. We identified 62 genes differentially expressed in ethanol-treated as compared to control zebrafish eyes from all sampling times over the period of retinal neurogenesis (24-48 hours post-fertilization). Application of the EDGE (extraction of differential gene expression) algorithm identified over 3000 genes differentially expressed over developmental time in ethanol-treated embryo eyes as compared to untreated embryo eyes. These lists included several genes indicating a mis-regulated cellular stress response (heat shock response) due to ethanol exposure. Combined treatment with sub-threshold levels of ethanol and a morpholino (MO) targeting heat shock factor 1 (hsf-1) mRNA resulted in a microphthalmic phenotype, suggesting convergent molecular pathways. Manipulation of the heat shock response by thermal preconditioning partially prevented ethanol-mediated microphthalmia while maintaining Hsf-1 expression. Together these data are consistent with roles for reduced Hsf-1 in mediating microphthalmic effects of embryonic ethanol exposure in zebrafish.
Project description:Ethanol is a well-known teratogen. While this teratogenic potential is well-characterized clinically, the mechanisms through which ethanol exposure results in developmental defects remain unclear. Here we use the zebrafish model to elucidate eye-specific mechanisms that may underlie ethanol-mediated microphthalmia (reduced eye size), using time-series microarray analysis of gene expression of eye tissues of embryos exposed to 1.5% ethanol vs. untreated embryos. We identified 62 genes differentially expressed in ethanol-treated as compared to control zebrafish eyes from all sampling times over the period of retinal neurogenesis (24-48 hours post-fertilization). Application of the EDGE (extraction of differential gene expression) algorithm identified over 3000 genes differentially expressed over developmental time in ethanol-treated embryo eyes as compared to untreated embryo eyes. These lists included several genes indicating a mis-regulated cellular stress response (heat shock response) due to ethanol exposure. Combined treatment with sub-threshold levels of ethanol and a morpholino (MO) targeting heat shock factor 1 (hsf-1) mRNA resulted in a microphthalmic phenotype, suggesting convergent molecular pathways. Manipulation of the heat shock response by thermal preconditioning partially prevented ethanol-mediated microphthalmia while maintaining Hsf-1 expression. Together these data are consistent with roles for reduced Hsf-1 in mediating microphthalmic effects of embryonic ethanol exposure in zebrafish. time series, 9 samples, no replicates
Project description:Transcriptional profiling performed from total eye RNA extracts of wildtype control fishes versus Prpf31 morpholino injected larvae (at ~72hpf) two-condition experiment: wildtype zebrafish versus MO-Prpf31 injected zebrafish eye RNA; 6 replicates each (extraction from 6 pools (~200 eyes each) of controls and 6 pools MO-Prpf31 (~200 eyes each))
Project description:To gain a better understanding of the factors necessary for successful CNS regeneration, a temporal analysis of the changes in gene expression in the eye caused by optic nerve injury was conducted. Dual color oligonucleotide microarrays were used to compare total RNA harvested from the eyes of sham-operated and optic nerve-injured fish at 3, 24, and 168 hours following surgery. Optic nerve injured fish are compared to sham-operated fish in order to eliminate gene expression due to non-neuronal damage and inflammatory response. Statistical analyses identified 131 genes with a 2.0-fold or greater difference in expression. Wild type zebrafish were obtained from a local pet store. Optic nerve injury was conducted using a severing model accomplished as follows. Zebrafish were anesthetized in 0.2% MS-222 dissolved in tank water. The muscles surrounding the eye were cut and the eye angled rostrally to expose the nerve. The optic nerve was then severed using microsissors without damaging the ophthalmic artery. In sham operated fish the muscles surrounding the eye were severed but the nerve was not damaged. RNA was extracted from the eye at three time points following surgery 3 hours, 24 hours, and 168 hours. RNA was pooled from multiple fish to achieve 10 ug total RNA. Samples were collected in triplicate per time point. Gene expression was analyzed on a dual color oligonucleotide array where the optic nerve injured fish were compared to sham-operated fish. Four samples of RNA were also collected from control fish and compared to each other on the microarray to confirm that processing did not create expression differences.