Phenotypic suppression of empty spiracles is prevented by buttonhead

• Published in: Nature (London) 2000-05, Vol.405 (6784), p.351-354
• Main Authors: Schöck, Frieder, Reischl, Joachim, Wimmer, Ernst, Taubert, Heike, Purnell, Beverly A., Jäckle, Herbert
• Format: Article
• Language: English
• Subjects: Animals; Animals, Genetically Modified; Binding Sites; Biological and medical sciences; buttonhead (btd) gene; Cell differentiation, maturation, development, hematopoiesis; Cell physiology; DNA-Binding Proteins - genetics; DNA-Binding Proteins - physiology; Drosophila; Drosophila - embryology; Drosophila - physiology; Drosophila Proteins; empty spiracles (ems) gene; EMS protein; Fundamental and applied biological sciences. Psychology; Genes; Homeodomain Proteins - physiology; HOX genes; Humanities and Social Sciences; Insects; letter; Molecular and cellular biology; multidisciplinary; Mutation; Phenotype; Protein Binding; Science; Science (multidisciplinary); Transcription Factors - genetics; Transcription Factors - physiology; Zinc Fingers
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/35012620

Unlike the trunk segments, the anterior head segments of Drosophila are formed in the absence of pair-rule 1 , 2 and HOX-cluster gene 3 expression, by the activities of the gap-like genes orthodenticle ( otd ), empty spiracles ( ems ) and buttonhead ( btd ) 4 , 5 . The products of these genes are transcription factors 6 , 7 , but only EMS has a HOX-like homeodomain 8 , 9 . Indeed, ems can confer identity to trunk segments 10 when other HOX-cluster gene activities are absent 3 , 11 . In trunk segments of wild-type embryos, however, ems activity is prevented by phenotypic suppression 10 , in which more posterior HOX-cluster genes inactivate the more anterior without affecting transcription or translation 12 . ems is suppressed by all other Hox-cluster genes and so is placed at the bottom of their hierarchy 10 . Here we show that misexpression of EMS in the head transforms segment identity in a btd -dependent manner, that misexpression of BTD in the trunk causes ems -dependent structures to develop, and that EMS and BTD interact in vitro . The data indicate that this interaction may allow ems to escape from the bottom of the HOX-cluster gene hierarchy and cause a dominant switch of homeotic prevalence in the anterior–posterior direction.