A hobo transgene that encodes the P-element transposase in Drosophila melanogaster: autoregulation and cytotype control of transposase activity.
Drosophila were genetically transformed with a hobo transgene that contains a terminally truncated but otherwise complete P element fused to the promoter from the Drosophila hsp70 gene. Insertions of this H(hsp/CP) transgene on either of the major autosomes produced the P transposase in both the male and female germlines, but not in the soma. Heat-shock treatments significantly increased transposase activity in the female germline; in the male germline, these treatments had little effect. The transposase activity of two insertions of the H(hsp/CP) transgene was not significantly greater than their separate activities, and one insertion of this transgene reduced the transposase activity of P(ry(+), Delta2-3)99B, a stable P transgene, in the germline as well as in the soma. These observations suggest that, through alternate splicing, the H(hsp/CP) transgene produces a repressor that feeds back negatively to regulate transposase expression or function in both the somatic and germline tissues. The H(hsp/CP) transgenes are able to induce gonadal dysgenesis when the transposase they encode has P-element targets to attack. However, this ability and the ability to induce P-element excisions are repressed by the P cytotype, a chromosomal/cytoplasmic state that regulates P elements in the germline.
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
Niemi
Jarad B
JB
D000818:Animals; D030801:Animals, Genetically Modified; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000201:enzymology / Q000235:genetics*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D008297:Male; D009154:Mutation; D019076:Transgenes; D019895:Transposases / Q000235:genetics*
D004251:DNA Transposable Elements; D019895:Transposases