Terminal pattern elements in Drosophila embryo induced by the torso-like protein

• Published in: Nature (London) Vol. 367; no. 6465; pp. 741 - 745
• Main Authors: Martin, J.R, Raibaud, A, Ollo, R
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 24.02.1994; Nature Publishing Group
• Subjects: Amino Acid Sequence; amino acid sequences; Animals; Base Sequence; Biological and medical sciences; Blotting, Southern; Chromosome Mapping; cloning; DNA; Drosophila; Drosophila - embryology; Drosophila - genetics; Drosophila Proteins; embryo (animal); Embryos; Female; Fundamental and applied biological sciences. Psychology; Genes; Genes, Insect; Genes. Genome; In Situ Hybridization; Insect Hormones; Insect Hormones - genetics; Insects; kinases; Life Sciences; Male; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Morphogenesis; Mutation; Neurons and Cognition; nucleotide sequences; Ovary; Ovary - chemistry; Protein-Tyrosine Kinases; Protein-Tyrosine Kinases - genetics; Proteins; Receptor Protein-Tyrosine Kinases; receptors; Restriction Mapping; RNA, Messenger; RNA, Messenger - analysis; tyrosine; Embryonic development; Nucleotide sequence; Enzyme; Insecta; Transferases; Drosophila; Gene expression; Drosophilidae; Arthropoda; Secretory protein; Chromosome DNA; Blastoderm; Mutation; Invertebrata; Localization; Protein-tyrosine kinase; Diptera
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/367741a0

The genes torso (tor) and torso-like (tsl) are two of the Drosophila maternal group genes implicated in a receptor tyrosine kinase signalling pathway that specifies terminal cell fate. Loss-of-function mutations in these loci cause an identical phenotype in which pattern elements from the anterior (acron) and posterior (telson) ends have been deleted. We have cloned the tsl gene and demonstrate here that, in agreement with previous genetic data, it encodes a protein that is secreted and whose transcription is restricted to specialized categories of follicle cells localized at the poles of the egg chamber. At early blastoderm stage, tsl protein forms a symmetrical concentration gradient at the poles on the surface of the devitellinized embryo. Unrestricted expression of the tsl protein in tsl female mutants induces terminal pattern elements and suppresses the formation of abdomen in embryos. These results suggest that the tsl protein is the ligand that binds to the torso receptor.