Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: An attempt to modify allelic frequencies at the Adh locus of a Drosophila melanogaster population in a tropical environment | Génét. Sél. Evol. 1983 15 4 495-500 An attempt to modify allelic frequencies at the Adh locus of a Drosophila melanogaster population in a tropical environment . DAVID Laboratoire de Biologie et Génệtique évolutives du . F 91190 Gif-sur-Yvette Summary One thousand laboratory-reared adults homozygous for the AdhF allele of the alcohol dehydrogenase locus were released in a tropical environment harboring a natural population in which the frequency of the F allele was very low about 2 p. 100 . During and after release bananas were provided to prevent rapid dispersal of the adult flies and to obtain their progeny. Samples of this population were studied for Adh genotype frequencies. As a consequence of matings between released and native flies the number of heterozygous flies increased significantly after one generation. However F allele frequency returned to its initial level after two generations suggesting a strong selective disadvantage of the heterozygotes. Key words Drosophila melanogaster climatic adaptation Adh locus balancing selection. Resume Tentative de modification des frequences alléliqites au locus Adh dans line population de Drosophila melanogaster en milieu tropical Un millier d adultes élevés au laboratoire et homozygotes pour 1 allèle AdhF ont été relâchés dans un environnement tropical qui abritait déjà une population naturelie ayant une frequence très faible de cet allele environ 2 p. 100 . Pendant 1 expérience des bananes ont été disposees en permanence afin de fixer la population et d obtenir une descendance. Des échantillons de cette population ont ensuite été étudiés. Après une génệ-ration un accroissement significatif des heterozygotes a ệtệ observe montrant le croi-sement entre les mouches indigenes et les mouches relâchées. Mais la frequence de 1 allèle F est revenue à son niveau initial après deux generations suggérant un désavantage selectif des heterozygotes. Mots clés Drosophila melanogaster adaptation climalique locus Adh .
