Identification of chromatin marks at TERRA promoter and encoding region

TERRA is a long non-coding RNA that is essential for telomere integrity. Although it is transcribed from subtelomeres and telomeres, how it is expressed in heterochromatic region is currently unknown. In this study, we focused our analysis on TERRA-encoding region TelBam3.4 and TelBam3.4-like sequences, and determined their transcription start sites, as well as enrichment of RNA polymerase II and histone modifications. We found that H3K4me3 and H3K9me3 are present at TERRA promoters, whereas H3K27ac and H3K9me3 are present at telomeric repeats. Consistently, we show that presence of active histone modifications H3K4me3 and H3K27ac are correlated to TERRA expression. These results mark an important step towards understanding telomere maintenance and transcription.