Analyses of heterochromatin distributions in the mutatnts defective in an RNAi-heterochromatin positive feedback loop in Tetrahymena [ChIP]

In the ciliated protozoan Tetrahymena, an RNAi-mediated feedback loop is important for assembling heterochromatin on the sequences that are removed from the somatic genome by programmed DNA elimination. Because heterochromatin is formed exclusively on the eliminated sequences, some mechanism must inhibit this feedback loop at the boundaries of the eliminated sequences. In this study, we show that the HP1-like protein Coi6p, its interaction partners Coi7p and Lia5p, and the histone demethylase Jmj1p are crucial for confining the formation of heterochromatin to the eliminated sequences. Overall design: 26 to 32-nt small RNAs from verious mutants or from immuno precipitated with Argonaute proteins were analyzed by high-throughput sequencing