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Photoperiodic regulation of insect and molluscan hormones
266
Molecular and Cellular Endocrinology, 40 (1985) 266
Elsevier Scientific Publishers Ireland, Ltd. MCE 01297
Book review Photoperiodic Regulation of Insect and Molluscan Hormones. Edited by R. Porter and G.M. Collins.
Ciba Foundation Symposium, Vol. 104. Pitman, London. 1984. 298 Pages. ~25.00. The aim of this symposium was to bring together scientists working on the photoperiodic clocks on the one hand, and on the endocrinological regulations of reproduction and development on the other, in invertebrates where these phenomena are actively investigated, namely insects, mites and molluscs. Until now, the two approaches have been quite separate, as underlined by D.S. Saunders in the introductory chapter. Broadly speaking, the first part of the volume is devoted to the analysis of the photoperiodic clocks, especially the link between the daily variations of illumination (or darkness) and the seasonal changes in reproduction and development, and gives a good overview of the different ‘models’ (circadian, hour-glass, internal and external coincidence, or a combination of two). This approach was presented either as general reviews (papers of Masaki, Pittendrigh et al.) or on a definite example (two-step model of photoperiod reception in spider mites by Veerman and Vaz Nunes, pupal diapause in Sarcophaga argyrostoma by Saunders and Bradley, diapause and pupal eclosion rhythm in geographical strains of Drosophila littoralis by Lankinen and Lumme). With the paper of Page on the circadian control of locomotion in Leucophaea maderae, begins the physiological analysis, with the evidence of one oscillator in each optic lobe of the brain. The eight following papers concern the endocrino-
0303-7207/85/$03.30
logical face of photoperiodism. Two of these are devoted to pulmonate molluscs, especially the links between photoperiod, hormones and neurohormones, and reproduction (the slug Limax maximus by Sokolove et al., Lymnaea stagnalis by Joosse). The six others are on insects: circadianclock control of hormone secretion in Samia by Ishizaki et al.; circadian control of ecdysteroids and ecdysis in Rhodnius by Steel and Ampleford; photoperiodic regulation of PTTH in Sarcophaga bullata by Roberts; oscillators, hormones and eclosion in Manduca by Truman; photoperiod, hormones and polymorphism in Aphids by Hardie; regulation of larval diapause in Diatraea by Chippendale. In most of these papers, a marked effort, often successful, was done to connect the physiological data with the models derived from the clock studies. In this context, the evidence for a circadian rhythm in hormone secretion, both in insects and in molluscs, appears very promising. Each paper is followed by a comprehensive discussion, and two general discussions are included, adding many facts and perspectives. As a whole, this book appears as a good source of up-to-date informations, very useful both for teaching and research work. The gap between ‘wet’ and ‘dry’ physiology (i.e. the ‘hormonal’ and ‘clock approaches) is not completely filled, but this symposium was surely a significant step toward this goal.
0 1985 Elsevier Scientific Publishers Ireland, Ltd.
Jules Hoffmann (France)
Molecular and Cellular Endocrinology, 40 (1985) 266
Elsevier Scientific Publishers Ireland, Ltd. MCE 01297
Book review Photoperiodic Regulation of Insect and Molluscan Hormones. Edited by R. Porter and G.M. Collins.
Ciba Foundation Symposium, Vol. 104. Pitman, London. 1984. 298 Pages. ~25.00. The aim of this symposium was to bring together scientists working on the photoperiodic clocks on the one hand, and on the endocrinological regulations of reproduction and development on the other, in invertebrates where these phenomena are actively investigated, namely insects, mites and molluscs. Until now, the two approaches have been quite separate, as underlined by D.S. Saunders in the introductory chapter. Broadly speaking, the first part of the volume is devoted to the analysis of the photoperiodic clocks, especially the link between the daily variations of illumination (or darkness) and the seasonal changes in reproduction and development, and gives a good overview of the different ‘models’ (circadian, hour-glass, internal and external coincidence, or a combination of two). This approach was presented either as general reviews (papers of Masaki, Pittendrigh et al.) or on a definite example (two-step model of photoperiod reception in spider mites by Veerman and Vaz Nunes, pupal diapause in Sarcophaga argyrostoma by Saunders and Bradley, diapause and pupal eclosion rhythm in geographical strains of Drosophila littoralis by Lankinen and Lumme). With the paper of Page on the circadian control of locomotion in Leucophaea maderae, begins the physiological analysis, with the evidence of one oscillator in each optic lobe of the brain. The eight following papers concern the endocrino-
0303-7207/85/$03.30
logical face of photoperiodism. Two of these are devoted to pulmonate molluscs, especially the links between photoperiod, hormones and neurohormones, and reproduction (the slug Limax maximus by Sokolove et al., Lymnaea stagnalis by Joosse). The six others are on insects: circadianclock control of hormone secretion in Samia by Ishizaki et al.; circadian control of ecdysteroids and ecdysis in Rhodnius by Steel and Ampleford; photoperiodic regulation of PTTH in Sarcophaga bullata by Roberts; oscillators, hormones and eclosion in Manduca by Truman; photoperiod, hormones and polymorphism in Aphids by Hardie; regulation of larval diapause in Diatraea by Chippendale. In most of these papers, a marked effort, often successful, was done to connect the physiological data with the models derived from the clock studies. In this context, the evidence for a circadian rhythm in hormone secretion, both in insects and in molluscs, appears very promising. Each paper is followed by a comprehensive discussion, and two general discussions are included, adding many facts and perspectives. As a whole, this book appears as a good source of up-to-date informations, very useful both for teaching and research work. The gap between ‘wet’ and ‘dry’ physiology (i.e. the ‘hormonal’ and ‘clock approaches) is not completely filled, but this symposium was surely a significant step toward this goal.
0 1985 Elsevier Scientific Publishers Ireland, Ltd.
Jules Hoffmann (France)