Direct and long-range action of a wingless morphogen gradient.
Wingless (Wg), a founding member of the Wingless/Int-1 (Wnt) family of secreted proteins, acts as a short-range inducer and as a long-range organizer during Drosophila development. Here, we determine the consequences of ectopically expressing (i) a wild-type form of Wg, (ii) a membrane-tethered form of Wg, and (iii) a constitutively active form of the cytosolic protein Armadillo (Arm), which normally acts to transduce Wg, and we compare them with the effects of removing endogenous Wg or Arm activity. Our results indicate that wild-type Wg acts at long range, up-regulating the transcription of particular target genes as a function of concentration and distance from secreting cells. In contrast, tethered Wg and Arm have only short-range or autonomous effects, respectively, on the transcription of these genes. We interpret these findings as evidence that Wg can act directly and at long range as a gradient morphogen during normal development.
Zecca
M
M
Zoologisches Institut der Universität Zürich, Switzerland.
Basler
K
K
Struhl
G
G
D000818:Animals; D030801:Animals, Genetically Modified; D051186:Armadillo Domain Proteins; D002454:Cell Differentiation / Q000502:physiology; D004330:Drosophila / Q000166:cytology / Q000196:embryology*; D029721:Drosophila Proteins; D004627:Embryonic Induction / Q000502:physiology; D005123:Eye / Q000166:cytology / Q000196:embryology; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D007866:Leg / Q000196:embryology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009024:Morphogenesis / Q000502:physiology; D011485:Protein Binding / Q000502:physiology; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D015534:Trans-Activators; D014157:Transcription Factors; D019076:Transgenes / Q000502:physiology; D014921:Wings, Animal / Q000166:cytology / Q000196:embryology; D051155:Wnt1 Protein
C495305:ARM protein, Drosophila; D051186:Armadillo Domain Proteins; D029721:Drosophila Proteins; D008565:Membrane Proteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D051155:Wnt1 Protein; C074622:wg protein, Drosophila