P element regulatory products enhance zeste1 repression of a P[white duplicated] transgene in Drosophila melanogaster
1990
Coen, D.
Drosophila P element mobilization is subject to acomplex array of regulatory mechanisms. A fruitful approach to study them is the use of insertion mutationswhose expression is influenced by P regulation. In the present report, it is shown that P elementsomatic products may influence the expression of an unrelated gene inserted in a P transposon. The P[w(dl)9.3]19DE transgene carries an in vitro modified white gene harboring a duplication of the 5'regulatory sequences. Expression of this transgene is repressed in a P background. No maternal effect isdetected and repression can be relieved as soon as P chromosomes are replaced by M ones. Theamplitude of repression is correlated to the P transposase activity of the individuals examined.Repression appears to be exerted by somatic products of complete autonomous P elements or of in vitro modifiedP elements lacking the capacity to express the fourth P exon. The P repression of P[w(dl)9.3]19DEis strongly dependent on the insertion site of this transgene. This P repression effect occursonly in the presence of the zeste(1) allele and is suppressed by Su(z)2 mutations. No qualitative differencesof transcription pattern are observed between white+ and P[w(dl)9.3]19DE in any backgrounds. P repressionacts to reduce the amount of the major white transcript. This suggests that P regulatoryproducts may act through cis-interactions at a distance of over 3 kb.
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