Project description:We characterized changes of transposon and mRNA expressions in armi, rhino ,aub, ago3 mutants with respect to wild type using Affy tiling array. In most of these mutants, mRNA expressions were mostly unchanged but increased expressions was observed for many transposons indicating the role of these proteins in silencing transposons in Drosophila ovaries Keywords: Tiling array transcriptome profiling
Project description:We characterized two independent insertional mutants of the AtEXO70A1 gene, encoding a subunit of the exocyst complex. Homozygous mutants exhibit a suite of phenotypic defects: polar growth of root hairs and stigmatic papillae is disturbed; organs are generally smaller; plants show loss of apical dominance and an indeterminate growth where instead of floral meristems new lateral inflorescences are initiated in a reiterative manner; exo70A1 mutants have dramatically reduced fertility. These results suggest that EXO70A1 is involved in cell and organ morphogenesis. Keywords: Expression profiling by array
Project description:Exploring miRNA-related antisense transcription in Arabidopsis through RNA transcript profiling of smRNA pathway-defective mutants on a custom high-resolution oligonucleotide array.
Project description:Two-organism transcriptome profiling of infected seedling, adult leaf, and tassel demonstrated that both the host and pathogen exhibit organ-specific expression programs. Phenotypic screening of U. maydis mutants deleted for suites of secreted protein genes and maize growth mutants demonstrated organ-restricted tumorigenesis. Two-dye, competitive hybridizations were performed on Agilent oligo arrays. Keywords: maize, pathogen, fungus, Ustilago, organ-specificity
Project description:Transcription profiling by array of mouse male retinas to investigate IGF-I-induced chronic gliosis and retinal stress IGF-I exert multiple effects in different retinal cell populations in both physiological and pathological conditions. Transgenic mice overexpressing IGF-I in the retina showed impaired electroretinographic responses at 6-7 months of age that worsen with age. This retinal neuronal dysfunction was correlated with the loss of rod photoreceptors, bipolar, ganglion and amacrines cells. Neuronal alterations were preceded by the overexpression of retinal stress markers, acute phase proteins and gliosis-related genes. IGF-I overexpression leads to chronic gliosis and microgliosis in TgIGF-I retinas, with mild oxidative stress, impaired recycling of glutamate and defective potassium buffering. These impaired supportive functions can contribute to neurodegeneration in TgIGF-I retinas, together with the increased production of pro-inflammatory cytokines, potential mediators of neuronal death.
Project description:Transcription factors, which regulate the spatiotemporal patterns of gene expression during organogenesis, often regulate multiple aspects of tissue morphogenesis, including cell-type specification, cell proliferation, cell death, cell polarity, cell shape, cell arrangement and cell migration. In this work, we describe a distinct role for Ribbon (Rib) in controlling cell shape changes during elongation of the Drosophila salivary gland (SG). Notably, the morphogenetic changes in rib mutants occurred without effects on general SG cell attributes such as specification, proliferation and apoptosis. Moreover, the abnormal cell/organ shape in rib mutants occurred without compromising epithelial-specific morphological attributes such as apicobasal polarity and junctional integrity. To identify the genes regulated by Rib that control cell and organ shape, we performed ChIP-seq analysis in embryos driving rib expression specifically in the SGs. To learn if the Rib binding sites identified in the ChIP-seq analysis were linked to changes in gene expression through transcriptional activation, repression, or both, we performed microarray analysis comparing RNA samples from age-matched wild-type and rib null embryos. From the superposed ChIP-seq and microarray gene expression data, we identified 60 genomic sites of bound Rib most likely to regulate SG-specific gene expression. We confirmed several of the identified Rib targets by qRT-pCR and/or in situ hybridization. Our results indicate that Rib regulates cell shape change in the Drosophila salivary gland via a diverse array of targets through both transcriptional activation and repression. Furthermore, our results suggest that a critical component of the SG morphogenetic gene network involving Rib is its autoregulation.
Project description:The number of cells in an organ is a major factor for the determination of organ size. However, genetic basis of cell number determination is not well understood. Three grandifolia-D (gra-D) mutants of Arabidopsis thaliana developed huge leaves containing two- to three-fold increased number of cells of the wild type. Tiling array and microarray analysis of gra-D mutants suggested that genes found in a lower part of chromosome 4 were upregulated, suggesting the occurrence of segmental chromosomal duplications in the gra-D mutants. These region contain positive regulators of cell proliferation such as AINTEGUMENTA (ANT) and cyclin genes such as CYCD3;1.
Project description:We characterized two independent insertional mutants of the AtEXO70A1 gene, encoding a subunit of the exocyst complex. Homozygous mutants exhibit a suite of phenotypic defects: polar growth of root hairs and stigmatic papillae is disturbed; organs are generally smaller; plants show loss of apical dominance and an indeterminate growth where instead of floral meristems new lateral inflorescences are initiated in a reiterative manner; exo70A1 mutants have dramatically reduced fertility. These results suggest that EXO70A1 is involved in cell and organ morphogenesis. Keywords: Expression profiling by array 4 samples were used in this experiment
Project description:Transcription factors, which regulate the spatiotemporal patterns of gene expression during organogenesis, often regulate multiple aspects of tissue morphogenesis, including cell-type specification, cell proliferation, cell death, cell polarity, cell shape, cell arrangement and cell migration. In this work, we describe a distinct role for Ribbon (Rib) in controlling cell shape changes during elongation of the Drosophila salivary gland (SG). Notably, the morphogenetic changes in rib mutants occurred without effects on general SG cell attributes such as specification, proliferation and apoptosis. Moreover, the abnormal cell/organ shape in rib mutants occurred without compromising epithelial-specific morphological attributes such as apicobasal polarity and junctional integrity. To identify the genes regulated by Rib that control cell and organ shape, we performed ChIP-seq analysis in embryos driving rib expression specifically in the SGs. To learn if the Rib binding sites identified in the ChIP-seq analysis were linked to changes in gene expression through transcriptional activation, repression, or both, we performed microarray analysis comparing RNA samples from age-matched wild-type and rib null embryos. From the superposed ChIP-seq and microarray gene expression data, we identified 60 genomic sites of bound Rib most likely to regulate SG-specific gene expression. We confirmed several of the identified Rib targets by qRT-pCR and/or in situ hybridization. Our results indicate that Rib regulates cell shape change in the Drosophila salivary gland via a diverse array of targets through both transcriptional activation and repression. Furthermore, our results suggest that a critical component of the SG morphogenetic gene network involving Rib is its autoregulation.