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E-GEOD-72598 - Gene expression data from wild-type (WT) and ribbon (rib) mutant Drosophila mid through late stage embryos
Released on 21 December 2015, last updated on 26 December 2015
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. Three independent collections of stage 11 – 16 rib1/ribP7 embryos and three of wild-type embryos were used for hybridization to Drosophila Genome 2.0 Chips. Scanned intensity values were normalized using RMA (Partek software) and statistical analysis analyses were performed using the Spotfire software package (TIBCO). Target genes were identified as those that were upregulated/downregulated (1.5-fold change cutoff, P < 0.05) in rib1/ribP7 embryos when compared with Oregon R controls.
transcription profiling by array
Deborah J Andrew <firstname.lastname@example.org>, Deborah Andrew, Rajprasad Loganathan
Ribbon regulates morphogenesis of the Drosophila embryonic salivary gland through transcriptional activation and repression. Loganathan R, Lee JS, Wells MB, Grevengoed E, Slattery M, Andrew DJ. , PMID:26477561