tailieunhanh - Báo cáo sinh học: "Reaction norms of size characters in relation to growth temperature in Drosophila melanogaster: an isofemale lines analysis"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Reaction norms of size characters in relation to growth temperature in Drosophila melanogaster: an isofemale lines analysis | Genet Sei Evol 1994 26 229-251 Elsevier INRA 229 Original article Reaction norms of size characters in relation to growth temperature in Drosophila melanogaster an isofemale lines analysis JR David1 B Moreteau1 JP Gauthier1 G Pétavy1 A Stockel2 AG Imasheva3 1 CNRS Laboratoire de Biologie et Génétique Evolutives 91198 Gif-sur-Yvette Cedex 2 INRA Station de Zoologie Agricole 33140 Pont-de-la-Maye France 3 Vavilov Institute of General Genetics 3 Gubkin Street 117809 Moscow Russia Received 7 June 1993 accepted 21 December 1993 Summary - Ten isofemale lines of Drosophila melanog aster recently collected in a French vineyard were submitted to 7 different developmental temperatures from 12 to 31 c encompassing the whole physiological range of the species. For each line and temperature 10 flies of each sex were collected randomly and 2 size-related traits were measured wing and thorax length. Both traits exhibited similar response curves a maximum size at a low temperature and a decrease on both sides. ANOVA showed significant variations between lines and also significant line-temperature interactions demonstrating different norms of reaction among the various lines. The shapes of the curves were further analysed by considering slope variations ie by calculating empirical derivative curves. The most interesting observation is that the temperature of maximum size TMS is not the same for the wing average C and the thorax average C . Genetic differences seem to exist between lines and TMS for both traits are correlated. Sexual dimorphism was analysed by considering the female male ratio for wing and thorax. Both traits provided the same information sexual dimorphism increased from to with increasing temperature and significant differences were found between lines. Finally the wing thorax ratio appeared as an original and most interesting trait. This ratio which is less variable than wing or thorax exhibited a monotonously decreasing sigmoid .