the geographical distribution of p-m hybrid dysgenesis in drosophila melanogaster大学出版社的地理分布混合在黑腹果蝇发育不全.pdfVIP

The geographical distribution of P-M hybrid dysgenesis in Drosophila melanogaster D. ANXOLABÉHÈRE, HU KAI D. NOUAUD, G. PÉRIQUET 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 expérimentale des Agrosystèmes, 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 fre- quency 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 them 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. Résumé Répart