caa a22 4500 386392978 CHVBK 20180307112126.0 cr unu---uuuuu 161130e198908 xx s 000 0 eng 10.1017/S0016672300028329 doi S0016672300028329 pii (NATIONALLICENCE)cambridge-10.1017/S0016672300028329 Comparison of the regulation of P elements in M and M′ strains of Drosophila melanogaster [Elektronische Daten] M and M′ strains of Drosophila melanogaster in the P-M system of hybrid dysgenesis were compared in two series of tests, with the following results. (1) The singed-weak hypermutability regulation test showed that M′ strains had lower P excision rates than M strains, suggesting that P-elements repression must occur in M′ strains although it is not detectable by gonadal dysgenesis assays. (2) The evolution of mixed P + M and mixed P + M′ populations was compared, using a strong P strain. The P + M cultures invariably evolved in a few generations into strong P cultures, while the P + M′ cultures evolved into P-type cultures with reduced P-factor potentials. However, after 30 generations of culture, both these types of mixed cultures had similar P copy numbers, suggesting that regulation of copy number had occurred in them. Copyright © Cambridge University Press 1989 Ronsseray Stéphane Laboratoire de Génétique des Populations, Universités Paris 6 et 7, Tour 42, 2 place jussieu, F75005 Paris, France Lehmann Monique Laboratoire de Génétique des Populations, Universités Paris 6 et 7, Tour 42, 2 place jussieu, F75005 Paris, France Periquet Georges Laboratoire de Biocénotique Expérimentale des Agrosystèmes, Faculté des Sciences, Parc Grandmont, 37200 Tours, France Genetical Research Cambridge University Press 54/1(1989-08), 13-22 0016-6723 54:1<13 1989 54 GRH https://doi.org/10.1017/S0016672300028329 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0016672300028329 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ronsseray Stéphane Laboratoire de Génétique des Populations, Universités Paris 6 et 7, Tour 42, 2 place jussieu, F75005 Paris, France NATIONALLICENCE 700 1- Lehmann Monique Laboratoire de Génétique des Populations, Universités Paris 6 et 7, Tour 42, 2 place jussieu, F75005 Paris, France NATIONALLICENCE 700 1- Periquet Georges Laboratoire de Biocénotique Expérimentale des Agrosystèmes, Faculté des Sciences, Parc Grandmont, 37200 Tours, France NATIONALLICENCE 773 0- Genetical Research Cambridge University Press 54/1(1989-08), 13-22 0016-6723 54:1<13 1989 54 GRH CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge