tailieunhanh - Báo cáo sinh học: " Directional selection on body weight and hybrid dysgenesis in Drosophila melanogaster"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Directional selection on body weight and hybrid dysgenesis in Drosophila melanogaster | Genet Set Evol 1991 23 205-219 Elsevier INRA 205 Original article Directional selection on body weight and hybrid dysgenesis in Drosophila melanogaster D Higuet Université p c M Curie Laboratoire de Généiique des Populations Mécanismes Moléculaires de la Speciation Tour 42 4e étage 4 place Jussieu 75251 Paris France Received 9 October 1990 accepted 20 March 1991 Summary - The influence of transposable elements in generating variation for body weight of Drosophila melanogaster was investigated by comparing the response to artificial divergent selection in dysgenic and nondysgenic crosses using 2 independent systems of hybrid dysgenesis PM and IR . Two replicates of initially dysgenic or nondysgenic crosses between Furnace Creek IP and Gruta RM strains were selected for increased and decreased body weight during 13 generations. A greater divergence in selection response was observed for the dysgenic lines than for the nondysgenic lines but this difference disappeared when selection was relaxed. The selected lines were analysed at generation 13 with respect to their dysgenesis properties as well as to the number and nature of their p and I elements. There was no correlation between the characteristics of the p and 1 elements in the selected lines and the intensity of response to selection for body weight. In both types of crosses hybrid dysgenesis induced modification in body weight variance probably by I and P-induced mutations. hybrid dysgenesis PM and IR systems body weight Drosophila melanogaster Resume Selection directionnelle sur le poids des adultes et dysgénèse des hybrides Chez Drosophila melanogaster. L aptitude des elements transposables à générer de la variabilité pour le caractère poids des adultes chez Drosophila melanogaster et donnant ainsi une plus grande prise à la selection a été éludtée en comparant la réponse à une selection bidirectionnelle suivant que le croisement originel était OU non dysgénique vis-à-vis des systèmes PM et 1R de dysgénèse des