Project description:cabut (cbt), is the Drosophila ortholog of the human TGF-β Inducible Early Gene 1 (dTIEG). It encodes a transcription factor involved in Drosophila dorsal closure (DC), and it is expressed in embryonic epithelial sheets and yolk cell during this process upon activation of the Jun N-terminal kinase (JNK) signaling pathway. Additional studies suggest that cbt may have a role in multiple developmental processes. We used microarrays to detail the target genes of Cbt during dorsal closure process cbtEP(2)2237E1 homozigote Drosophila mutant embryos were selected at 10-13 stage (during dorsal closure process) from non-GFP embryos from the line cbtEP(2)2237E1/Cy0, twi-eGFP line by embryo sorter assays. In parallel, samples of white embryos at same stages (as control) were sorting also by embryo sorter. Also using UAS-GAL4 system, Cbt was overexpressed in the embrionic epidermis during 10-13 stage by epidermal driver (69B-Gal4) and UAS-Cbt line.
Project description:Tissue morphogenesis relies on proper differentiation of morphogenetic domains, adopting specific cell behaviours. Yet, how signalling pathways interact to determine and coordinate these domains remains poorly understood. Dorsal closure (DC) of the Drosophila embryo represents a powerful model to study epithelial cell sheet sealing. In this process, JNK (JUN N-terminal Kinase) signalling controls leading edge (LE) differentiation generating local forces and cell shape changes essential for DC. The LE represents a key morphogenetic domain in which, in addition to JNK, a number of signalling pathways converges and interacts (anterior/posterior -AP- determination; segmentation genes, such as Wnt/Wingless; TGFβ/Decapentaplegic). To better characterize properties of the LE morphogenetic domain, we used microarrays to identify genes whose expression is regulated by the JNK pathway during dorsal closure of the Drosophila embryo.
Project description:cabut (cbt), is the Drosophila ortholog of the human TGF-β Inducible Early Gene 1 (dTIEG). It encodes a transcription factor involved in Drosophila dorsal closure (DC), and it is expressed in embryonic epithelial sheets and yolk cell during this process upon activation of the Jun N-terminal kinase (JNK) signaling pathway. Additional studies suggest that cbt may have a role in multiple developmental processes. We used microarrays to detail the target genes of Cbt during dorsal closure process
Project description:Morphogenesis of an epithelium relies on the differentiation of cellular territories that further adopt specific cell behavior. During dorsal closure of the Drosophila embryo, distinct territories and several signaling pathways (JNK, Wingless, Dpp, …) bring their own contribution to the migration of the epithelial sheets. In particular, the ectodermal leading edge, which is specified by the JNK pathway, behaves as a purse-string under the action of an acto-myosin cable and as a zipper under the action of cellular extensions. How the leading edge, which is supposed to be a uniform raw of cell, integrates the input of the different signaling pathways is poorly understood. We used microarrays to identify genes whose expression is regulated by the JNK pathway during dorsal closure of the Drosophila embryo. Three genetic conditions were compared: wild-type (WT), gain of function (GOF) and loss of function (LOF). For the GOF embryos, the JNK pathway was strongly activated by expressing HepACT in the ectoderm using the UAS-GAL4 system (69B-GAL4). For the LOF embryos, we used a combination of 2 alleles, heprev75 and hep1. Carefully staged embryos, corresponding to stages 13 and 14, were collected and for each condition, three independent RNA samples were prepared to be hybridized on the microarrays.
Project description:Whole-Genome Analysis of Dorsal-Ventral Patterning in the Drosophila Embryo. The maternal Dorsal regulatory gradient initiates the differentiation of several tissues in the early Drosophila embryo. Whole-genome microarray assays identified as many as 40 new Dorsal target genes, which encode a broad spectrum of cell signaling proteins and transcription factors. Evidence is presented that a tissue-specific form of the NF-Y transcription complex is essential for the activation of gene expression in the mesoderm. Tissue-specific enhancers were identified for new Dorsal target genes, and bioinformatics methods identified conserved cis-regulatory elements for coordinately regulated genes that respond to similar thresholds of the Dorsal gradient. The new Dorsal target genes and enhancers represent one of the most extensive gene networks known for any developmental process. Stathopoulos et al., Cell, Vol 111, 687-701, November 2002.