tailieunhanh - Báo cáo sinh học: " Body size and developmental temperature in Drosophila simulans: comparison of reaction norms with sympatric "

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Body size and developmental temperature in Drosophila simulans: comparison of reaction norms with sympatric | Genet Sei Evol 1996 28 415-436 @ Elsevier INRA 415 Original article Body size and developmental temperature in Drosophila simulans . comparison of reaction norms with sympatric Drosophila melanogaster JP Morin1 B Moreteau1 G Pétavy1 AG Imasheva2 JR David1 1 Laboratoire de populations génétique et evolution CNRS 91198 Gif-sur-Yvette cedex France 2 Vavilov Institute of General Genetics 3 Gubkin Street 117809 Moscow Russia Received 10 November 1995 accepted 7 July 1996 Summary - Reaction norms of two size-related traits wing and thorax length were analyzed in relation to growth temperature in a French natural population of Drosophila simulans using the isofemale lines method. The wing thorax ratio was also studied. Data were compared to those of the sibling species Drosophila melanogaster from the same locality. Flies were reared at seven constant temperatures representing the whole thermal range of the two species. Phenotypic and genetic variabilities were analyzed. For investigating the shape of the response curves ie reaction norms two methods were used analysis of slope variations and polynomial adjustments. As expected from the relatedness of the two species many similarities were observed. Notably the reaction norms of wing and thorax lengths exhibited a maximum at low temperature while the wing thorax ratio was a regularly decreasing sigmoid curve. Numerous and sometimes great differences were also observed. At the phenotypic level D simulans was generally more variable while at the genetic level it was less variable than D melanogaster. Isofemale line heritabilities varied according to growth temperature but with different patterns in the two species. In both species sexual dimorphism increased with temperature but the average values and the response curves were different. The reaction norms of wing and thorax lengths were mainly characterized by different TMSs temperatures of maximum size with lower values in D simulans. This species was also characterized by