Long non-coding RNAs have age-dependent diurnal expression that coincides with age-related changes in genome-wide facultative heterochromatin.

The data suggest a model where some age-related changes in diurnal expression are partially attributed to age-related alterations to rhythmic facultative heterochromatin. The changes in heterochromatin are potentially mediated by changes in diurnal lncRNA creating an interlocked circadian-chromatin regulatory network that undergoes age-dependent metamorphosis.