Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: A quantitative analysis of the mechanism that controls body size in Manduca sexta. | J. Biol. Journal of Biology BioMed Central Research article Open Access A quantitative analysis of the mechanism that controls body size in Manduca sexta HF Nijhout G Davidowitz and DA Roff Addresses Department of Biology Duke University Durham NC 27708 USA. Department of Ecology and Evolutionary Biology University of Arizona Tucson AZ 85721 USA. Department of Biology University of California Riverside CA 92521 USA. Correspondence HF Nijhout. Email hfn@ Received 30 January 2006 Revised 13 April 2006 Accepted 28 April 2006 Published 2 August 2006 Journal of Biology 2006 5 16 The electronic version of this article is the complete one and can be found online at http content 5 5 16 2006 Nijhout et al. licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background Body size is controlled by mechanisms that terminate growth when the individual reaches a species-specific size. In insects it is a pulse of ecdysone at the end of larval life that causes the larva to stop feeding and growing and initiate metamorphosis. Body size is a quantitative trait so it is important that the problem of control of body size be analyzed quantitatively. The processes that control the timing of ecdysone secretion in larvae of the moth Manduca sexta are sufficiently well understood that they can be described in a rigorous manner. Results We develop a quantitative description of the empirical data on body size determination that accurately predicts body size for diverse genetic strains. We show that body size is fully determined by three fundamental parameters the growth rate the critical weight which signals the initiation of juvenile hormone breakdown and the interval between the critical weight and the secretion of ecdysone. .
