P-Element repression in Drosophila melanogaster by variegating clusters of P-lacZ-white transgenes.
In Drosophila, clusters of P transgenes (P-lac-w) display a variegating phenotype for the w marker. In addition, X-ray-induced rearrangements of chromosomes bearing such clusters may lead to enhancement of the variegated phenotype. Since P-lacZ transgenes in subtelomeric heterochromatin have some P-element repression abilities, we tested whether P-lac-w clusters also have the capacity to repress P-element activity in the germline. One cluster (T-1), located on a rearranged chromosome (T2;3) and derived from a line bearing a variegating tandem array of seven P-lac-w elements, partially represses the dysgenic sterility (GD sterility) induced by P elements. This cluster also strongly represses in trans the expression of P-lacZ elements in the germline. This latter suppression shows a maternal effect. Finally, the combination of variegating P-lac-w clusters and a single P-lacZ reporter inserted in subtelomeric heterochromatic sequences at the X chromosome telomere (cytological site 1A) leads to strong repression of dysgenic sterility. These results show that repression of P-induced dysgenic sterility can be elicited in the absence of P elements encoding a polypeptide repressor and that a transgene cluster can repress the expression of a single homologous transgene at a nonallelic position. Implications for models of transposable element silencing are discussed.
Ronsseray
S
S
Laboratoire Dynamique du Génome et Evolution, Institut Jacques Monod, UMR7592, CNRS-Universités Paris 6 et 7, 75251 Paris Cedex 05, France. ronsseray@ijm.jussieu.fr
Boivin
A
A
Anxolabéhère
D
D
D018528:ATP-Binding Cassette Transporters; D000483:Alleles; D000818:Animals; D015139:Blotting, Southern; D003433:Crosses, Genetic; D004330:Drosophila; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D020868:Gene Silencing; D006059:Gonadal Dysgenesis / Q000235:genetics; D006570:Heterochromatin / Q000378:metabolism; D019476:Insect Proteins / Q000235:genetics*; D007763:Lac Operon / Q000235:genetics*; D008297:Male; D008957:Models, Genetic; D005810:Multigene Family; D009154:Mutation; D010053:Ovary / Q000378:metabolism; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D013489:Suppression, Genetic; D019076:Transgenes
D018528:ATP-Binding Cassette Transporters; D029721:Drosophila Proteins; D005136:Eye Proteins; D006570:Heterochromatin; D019476:Insect Proteins; C059254:w protein, Drosophila