Torso signalling regulates terminal patterning in Drosophila by antagonising Groucho-mediated repression

• Published in: Development (Cambridge) Vol. 124; no. 19; pp. 3827 - 3834
• Main Authors: Paroush, Z, Wainwright, S M, Ish-Horowicz, D
• Format: Journal Article
• Language: English
• Published: England The Company of Biologists Limited 01.10.1997
• Subjects: Abdomen; Animals; Basic Helix-Loop-Helix Transcription Factors; Body Patterning; Crosses, Genetic; DNA-Binding Proteins - biosynthesis; DNA-Binding Proteins - metabolism; Drosophila - embryology; Drosophila Proteins; Embryo, Nonmammalian - cytology; Embryo, Nonmammalian - physiology; Female; Gene Expression Regulation, Developmental; Genes, Insect; Insect Hormones - biosynthesis; Male; Mutagenesis; Receptor Protein-Tyrosine Kinases - physiology; Repressor Proteins - biosynthesis; Repressor Proteins - metabolism; Signal Transduction; Zinc Fingers; Zygote - physiology
• ISSN: 0950-1991; 1477-9129
• DOI: 10.1242/dev.124.19.3827

Patterning of the non-segmental termini of the Drosophila embryo depends on signalling via the Torso receptor tyrosine kinase (RTK). Activation of Torso at the poles of the embryo triggers restricted expression of the zygotic gap genes tailless (tll) and huckebein (hkb). In this paper, we show that the Groucho (Gro) corepressor acts in this process to confine terminal gap gene expression to the embryonic termini. Embryos lacking maternal gro activity display ectopic tll and hkb transcription; the former leads, in turn, to lack of abdominal expression of the Kruppel and knirps gap genes. We show that torso signalling permits terminal gap gene expression by antagonising Gro-mediated repression. Thus, the corepressor Gro is employed in diverse developmental contexts and, probably, by a variety of DNA-binding repressors.