Most non-coding transcription peaks in LOC phase. This includes the majority of anti-sense transcription, and many small transcripts that emanate from the vicinity of the ca. 300 Long Terminal Repeats (LTR) in the yeast genome elements, remainders of former LTR retrotransposon, where the transposon itself has been lost, but the LTR has remained in the genome. Notably, LTR are considered to act as both promoters and transcription terminators (McClintock 1950; Curcio, Lutz, and Lesage 2015; Moller et al. 2015), i.e., they are mobile regulatory elements involved in the evolution of new transcripts or new regulation of existing genes. In yeast, LTR are often found associated with tRNA genes and replication origins. Here, we find them enriched in LOC phase-transcribed domains, and enriched especially at the borders of such domains.
Browse the temporal transcription landscape in the YRO Genome Browser or find examples of the complex transcriptional landscape around transposons and their LTR elements in this slide deck.