Insertion of a CACTA transposable element leads to somatic variegation and germinal instability of p1 gene expression in the absence of element excision
2007
Peterson, P.A., Iowa State University, Ames, IA (USA)
Here we report the molecular analysis of a new p1 mutant allele, p1-vv85, that showed both somatic and germinal instability. A novel CACTA transposom-like element was isolated from the second intron of the p1 gene in both the mutant p1-vv85 and its stable pigmented revertant allele. Transcriptional analysis indicated that transcription of the p1 gene in p1-vv85 terminated prematurely in the vinicity of the CACTA insertion site. The results are consistent with a model in which binding of a suppressor-like factor to the CACTA insertion element interferes with transcription elongation. We propose that the reversion of p1-vv85 to a functional P1-rr state does not result from transposable element excision, but rather from relief of suppression which is correlated with methylation of the CACTA insertion element.
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