Temporal mRNA regulation

Bowden NA, Scott RJ, Tooney PA. 2007. Altered expression of regulator of G-protein signalling 4 (RGS4) mRNA in the superior temporal gyrus in schizophrenia. Schizophr Res 89 165-168. 

Phage T4 has numerous promoters only a few of which can be recognized by E. coli RNA polymerase. However, unlike T7, the late promoters are made available by successive modification of the E. coli enzyme. These modifications are of two types addition of phage-encoded protein subunits and chemical modification of preexisting subunits. Temporal regulation occurs because the gene responsible for the first modification is encoded in the first set of mRNAs, that for the second modification in the second set, and so on. To ensure that the late mRNA, which encodes the structural proteins and the lysis enzyme, is not synthesized until adequate DNA has been made by the replication system, the template for this late mRNA cannot be parental T4 DNA but must be a replica. 

The expression of FGFs at both the RNA and protein level is generally very low in normal adult tissues peaks of FGF expression often occur in brief phases of embryogenesis. In situ hybridization studies have provided evidence for tissue-specific patterns of FGF mRNA expression in early stages of embryonic development (see Section 4.5). Such spatial and temporal regulation of gene expression correlates well with some of the documented effects of these factors, such as induction of mesoderm (by FGF-2, -3, -4, and other FGFs reviewed by Slack, 1994), or induction of specific primordia such as the limbs (by FGF-2 and -4 reviewed by Niswander et al., 1994 Olwin et al., 1994), the eye (by FGF-1 and -2 reviewed by McAvoy et al., 1991), and the inner ear (by FGF-3 Represa et al., 1991 Mansour, 1994). 

Fig. 11.7. Sustained oscillations in the model for regulation of per mRNA by the PER protein in Drosophila (Goldbeter, 1995). Shown in (a) is the temporal variation in per mRNA (M), together with the variation in nuclear PER (Pn) and in the total amount of PER protein (P,). Concomitant changes in the unphosphorylated (Pq) and phosphorylated, cj osolic (Pj and P2) and nuclear forms of PER me shown in (b), together with the total, nonconserved amoimt of PER protein. The curves are obtained by numerical integration of eqns (ll.la-e) P, is given by eqn (11.2). Parameter values are v, = 0.76 p.M/h, = 0.65 pM/h, k, = 0.38 h , = 0.95 p.M/h, A , = 1.9 h = 1.3 h = 1 p.M,...

Paisley, EA, Park, El, Swartz, DA, Mangian, HJ, Visek, WJ, and Kaput, J, Temporal-regulation of serum lipids and stearoyl coa desaturase and lipoprotein lipase mrna in balb/chnn mice, J Nutr, 1996. 126(11) 2730-2737. 

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