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178. Wingless signaling leads to an asymmetric response to decapentaplegic-dependent signaling during sense organ patterning on the notum of Drosophila melanogaster

Author

Phillips, Roger G., Warner, Natasha L., and Whittle, J. Robert S.

Subjects
Hedgehogs -- Growth, Cellular signal transduction -- Research, Drosophila -- Growth, Developmental biology -- Research, Biological sciences
Abstract

Wnt and Decapentaplegic cell signaling pathways act synergistically in their contribution to macrochaete (sense organ) patterning on the notum of Drosophila melanogaster. The Wingless-signaling pathway was ectopically activated by removing Shaggy activity (the homologue of vertebrate glycogen synthase kinase 3) in mosaics. Proneural activity is asymmetric within the Shaggy-deficient clone of cells and shows a fixed 'polarity' with respect to body axis, independent of the precise location of the clone. This asymmetric response indicates the existence in the epithelium of a second signal, which we suggest is Decapentaplegic. Ectopic expression of Decapentaplegic induces extra macrochaetes only in cells which also receive the Wingless signal. Activation of Hedgehog signaling generates a long-range signal which can promote macrochaete formation in the Wingless activity domain. This signal depends upon decapentaplegic function. Autonomous activation of the Wingless signal response in cells causes them to attenuate or sequester this signal. Our results suggest a novel patterning mechanism which determines sense organ positioning in Drosophila. Key Words: wingless; shaggy/zeste-white 3; decapentaplegic; hedgehog; signal transduction; spatial patterning; imaginal discs.

Published
1999

179. Open pit design in the 90s.

Author

Whittle J., Mining industry optimisation conference MINOPT 91,Sydney 05-Jun-9106-Jun-91, Rozman L.I., Whittle J., Mining industry optimisation conference MINOPT 91,Sydney 05-Jun-9106-Jun-91, and Rozman L.I.

Abstract

Pit design techniques before optimisation are reviewed followed by a description of the optimisation procedure and the extensions to it which allow the automatic generation of nested families of pits. The properties of families of nested pits are examined and how they can be used to simulate certain mining sequences and schedules is explained. The Paddington II case study is then presented., Pit design techniques before optimisation are reviewed followed by a description of the optimisation procedure and the extensions to it which allow the automatic generation of nested families of pits. The properties of families of nested pits are examined and how they can be used to simulate certain mining sequences and schedules is explained. The Paddington II case study is then presented.

Published
1991

190. Recent studies on xanthine oxidase and related enzymes

Author

Bray, R. C., primary, Bennett, B., additional, Burke, J. F., additional, Chovnick, A., additional, Doyle, W. A., additional, Howes, B. D., additional, Lowe, D. J., additional, Richards, R. L., additional, Turner, N. A., additional, Ventom, A., additional, and Whittle, J. R. S., additional

Published
1996
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