| Comments |
"Mouse L cells, which divide every 12–14 h, support a continuous synthetic rate of ~2×10^8 nucleotides/min with 39, 58, and 3% into prerRNA,
pre-mRNA (hnRNA), and 4–5S RNA, respectively
(Brandhorst et al., 1974 PMID 22003578). With synthetic rates of 2.5 and 2 kbp/min
for pol I and pol II/III, respectively (see above), and
average transcript lengths of 13, 10, and 0.1 kb for
pol I, pol II, and pol III, respectively, these values
correspond to ~30,000, 60,000, and 3,000 engaged
pol I, II, and III complexes/cell, respectively. In
rabbit erythroid cells, levels of RNA synthesis are at
least 10-fold lower (Hunt 1976 PMID 1016252), though similar proportions
of pol I and II activity are seen." |