Up to the present, a number of different expression systems have been used to express apoptin, including E. coli, baculovirus-insect cells and plant cells [ 15- 18].
Although the discrepancy between our observations and those previously reported remain unclear, one difference may be the use of different expression systems.
Because the translation initiation hypothesis predicts that highly expressed genes should be more likely to have +4G than lowly expressed genes, we have used genes of different expression levels to check this prediction.
One of the major problems is the development of expression metrics that will allow comparisons of different expression levels and also provide identification of differentially expressed genes.
The use of different expression systems, and reductases, may explain the difference in Km values obtained for the C. roseus CYP75A8 enzyme in the two studies [ 28].
This is shown here by the intestine having the greatest transcriptional response in terms of the number of genes expressed at different levels and the magnitude of different expression of these genes.
The use of different expression systems in these studies might be another reason for the differences in protein localization.
For heterologous gene expression in E. coli a number of different expression vectors and host strains are used.
To construct an efficient vector system (Fig. 1a), we analyzed the efficiency of different expression elements in rice.
In addition, many novel antibody molecules have been developed which can be produced in a variety of different expression systems.
According to Cho et al. (1998) the growth variations in hairy root clones could occur because of different expression of T-DNA genes present in the transformed roots.
