Intron length increases oscillatory periods of gene expression in animal cells.

Introns may affect gene expression by increasing the time required to transcribe the gene. One way for extended transcription times to affect the behavior of a gene expression program is through a negative feedback loop. Here, we show that a logically engineered negative feedback loop in animal cells produces expression pulses, which have a broad time distribution that increases with intron length. These results in combination with mathematical models provide insight into what may produce the intron-dependent pulse distributions. We conclude that the long production time required for large intron-containing genes is significant for the behavior of gene expression programs.