If lincRNAs are specifically regulated at the level of transcription, it is expected that their expression levels are specific to their tissue source. Indeed, prior studies of lincRNAs have shown that lincRNAs display very strong tissue-specific expression [16], [19]. To test whether this remains true with our expanded set of lincRNAs we performed unsupervised hierarchical clustering using lincRNA expression levels in replicate RNA-seq datasets from various tissues (Figure S4). Replicates of each tissue type strongly clustered together, indicating that lincRNA differential expression is indeed reproducibly tissue-specific, supporting specific regulation of lincRNA expression.
