Regulation of P-element transposase activity in Drosophila melanogaster by hobo transgenes that contain KP elements.
Fusions between the Drosophila hsp70 promoter and three different incomplete P elements, KP, SP, and BP1, were inserted into the Drosophila genome by means of hobo transformation vectors and the resulting transgenic stocks were tested for repression of P-element transposase activity. Only the H(hsp/KP) transgenes repressed transposase activity, and the degree of repression was comparable to that of a naturally occurring KP element. The KP transgenes repressed transposase activity both with and without heat-shock treatments. Both the KP element and H(hsp/KP) transgenes repressed the transposase activity encoded by the modified P element in the P(ry(+), Delta2-3)99B transgene more effectively than that encoded by the complete P element in the H(hsp/CP)2 transgene even though the P(ry(+), Delta2-3)99B transgene was the stronger transposase source. Repression of both transposase sources appeared to be due to a zygotic effect of the KP element or transgene. There was no evidence for repression by a strictly maternal effect; nor was there any evidence for enhancement of KP repression by the joint maternal transmission of H(hsp/KP) and H(hsp/CP) transgenes. These results are consistent with the idea that KP-mediated repression of P-element activity involves a KP-repressor polypeptide that is not maternally transmitted and that KP-mediated repression is not strengthened by the 66-kD repressor produced by complete P elements through alternate splicing of their RNA.
Simmons
Michael J
MJ
Department of Genetics, Cell Biology and Development, University of Minnesota, Saint Paul, Minnesota 55108-1095, USA. simmo004@tc.umn.edu
Haley
Kevin J
KJ
Grimes
Craig D
CD
Raymond
John D
JD
Fong
Joseph C L
JC
D000818:Animals; D030801:Animals, Genetically Modified; D003433:Crosses, Genetic; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000201:enzymology / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation; D008297:Male; D009154:Mutation; D019076:Transgenes; D019895:Transposases / Q000235:genetics*
D004251:DNA Transposable Elements; D019895:Transposases