tailieunhanh - Báo cáo sinh học: Phenotypic plasticity of body pigmentation in Drosophila: correlated variations between segments

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Phenotypic plasticity of body pigmentation in Drosophila: correlated variations between segments | Genet. Sei. Evol. 30 1998 181-194 Inra Elsevier Paris 181 Original article Phenotypic plasticity of body pigmentation in Drosophila correlated variations between segments Patricia Giberta Brigitte Moreteaua Samuel M. Scheinerb Jean R. David a a Laboratoire populations génétique et evolution Centre national de la recherche scientifique 91198 Gif-sur-Yvette cedex France b Department of Life Sciences Arizona State University West . Box 37100 Phoenix AZ 85069 USA Received 8 September 1997 accepted 22 January 1998 Abstract - Phenotypic plasticity of body pigmentation the last three abdominal segments and the mesothorax was investigated as a function of growth temperature in Drosophila melanogaster and Drosophila simulans. Two populations of each species were analysed from two French localities with different climatic conditions. For each population ten isofemale lines were reared at temperatures ranging from 14 to 31 C. Two methods were used and compared to estimate genetic correlations rg between segments a simple method using directly the family mean values rm and a theoretically better method correcting variances and covariances for family size rc . Both methods produced very similar data but the first one rm was preferred because it allowed an estimate of rg in all cases. Genetic and phenotypic correlations decreased regularly with distance between body segments revealing an antero-posterior gradient the extension of dark pigmentation is determined by increasingly different genetic systems in more distant segments. Genetic correlations were substantially larger than phenotypic correlations in opposition to Cheverud s conjecture although the two sets of values were highly correlated. Inra Elsevier Paris D. melanogaster D. simulans genetic correlation Cheverud s conjecture isofemale lines Resume - Plasticité phénotypique de la pigmentation corporelle chez Drosophila variations corrélées entre segments. La plasticité phénotypique de la pigmentation corporelle trois