Abstract
p-SINE is a retroposon dispersed in the rice genome. Analysis of the p-SINE transcripts from rice cultured cells and in vitro transcription of the p-SINE sequence revealed that it was transcribed by the internal promoter. Most of the transcripts from cultured cells were from members of the RA subfamily, which have transposed recently. The amount of the transcripts has increased dramatically by treating cells with inhibitors of DNA methylation. Genomic sequence of a RA member was heavily methylated, and was undermethylated by the inhibitor treatment. These results suggest that the expression of RA members is repressed by DNA methylation. In the rice plant, p-SINE was expressed in panicles and roots, but not in leaves. Most of the transcripts in panicles were also from RA members, suggesting that the expression of RA members is regulated tissue-specifically.
