Why eukaryotic cells use introns to enhance gene expression: Splicing reduces transcription-associated mutagenesis by inhibiting topoisomerase I cutting activity

Table 1 Comparisons between the intron-containing genes and the intronless genes of Saccharomyces cerevisiae.

	Intron-containing genes	Intronless genes	P(Mann-Whitney U test)
mRNA abundance (molecules/cell)	4.9	1.3	10^-³³
	23 ± 38	4.2 ± 18
Nascent transcription rate (molecules/min)	0.27	0.12	7 × 10^-28
	0.37 ± 0.33	0.16 ± 0.20
RNA polymerase II density (molecules/kb)	0.18	0.077	7 × 10^-28
	0.25 ± 0.22	0.11 ± 0.13

Data from [37]. In each item, we show the median value and the average ± standard deviation.

ISSN: 1745-6150