Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: The geographical distribution of P-M hybrid dysgenesis in Drosophila melanogaster | Génét. Sél. Evol. 1984 16 1 15-26 The geographical distribution of P-M hybrid dysgenesis in Drosophila melanogaster D. ANXOLABÉHÈRE HU KAI p NOUAUD G. PÉRIQUET and s. RONSSERAY Laboratoire de Génétique des Populations tour 42 Université Paris VII 2 place Jussieu F 75005 Paris Department of Biology Northwestern University Xian People s Republic of China Institut de Biocénotique experimentale des Agrosystemes Université de Tours Parc Grandmont F 37200 Tours Summary In Drosophila melanogaster the syndrome of germline abnormalities generated in the P-M system is caused by transposable elements known as the p element family. The frequency of gonadal dysgenesis GD sterility characteristic of the P-M system was estimated in 120 populations collected in 1980-1983 from arround the world in order to determine the present distribution of this system of hybrid dysgenesis. Marked geographical differences appear between these populations. In North America most of theni possess individuals of the p and the Q type whereas the M type is absent or present at only very low frequencies. A similar pattern has been found in central Africa whereas the p type is practically absent in North Africa Europe and Asia. In these regions another pattern exists. In France the Q type is very frequent and the M type of low frequency whereas M becomes very common going to the east of Yugoslavia and Tunisia towards India China and Japan. Hypotheses on the evolution of the P-M system in natural populations polymorphic for the p elements will be discussed. Key words Transposable elements populations polymorphism evolution. Resume Repartition géographique du système P-M de dysgénésie des hybrides Chez Drosophila melanogaster Chez Drosophila melanogaster la dỵsgénésie des hybrides due aux elements transpo-sables de la famille p est un syndrome d anomalies génétiques incluant une stérilité thermo-dépendante et un fort taux de mutation. Afin de déterminer la distribution de ce système parmi les populations