Ovalbumin gene expression

Kwong AD, Frenkel N. 1985. The herpes simplex virus amplicon. IV. Efficient expression of a chimeric chicken ovalbumin gene amplified within defective virus genomes. Virology 142 421-25... 

Since E. coli lack the machinery to excise introns and splice exons, they would make a meaningless mRNA if presented with ovalbumin genomic DNA. Therefore, if you wish to express the ovalbumin gene in E. coli, you must use its cDNA, which contains the information in the eight exons, but no introns. 

Upstream of the ovalbumin gene are two genes, X and Y, which are homologous with the ovalbumin gene and have arisen by gene duplication. All three are contained within 46 kb DNA. All three genes are under steroid hormonal control, and all three are expressed in the oviduct of the laying hen, but X and Y at only about 2% the level of ovalbumin mRNA (LeMeur et al, 1981). 

Royal, A., Garapin, A., Cami, B. et al. (1979). The ovalbumin gerre region common features in the organization of three genes expressed in chicken oviduct under hormonal control. Nature, 279, 125-32. 

It has been shown that, during secondary stimulation with estrogen, there is an increase in the concentration of nuclear receptor molecules followed by an increase in the available initiation sites for RNA synthesis on the chromatin (Tsai et al., 1975b Kalimi et al., 1976 Anderson et al., 1972). Using hybridization techniques, it has been shown that control of the expression of the ovalbumin gene by estrogen occurs at the transcriptional level (Harris et al., 1976). 

Harris, S. E., Schwartz, R. J., Tsai, M.-J., and O Malley, B. W., 1976, Effect of estrogen on gene expression in the chick oviduct. In vitro transcription of the ovalbumin gene in chromatin, /. Biol. Chem. 251 524. 

Problem 2 of Chapter 6 in the text refers to the expression of a eukaryotic gene—chicken ovalbumin— in E. coli. To avoid transcribing and translating intron sequences, you should use cDNA for protein expression. However, if you introduce only the chicken ovalbumin cDNA into bacteria, the level of expression of functional protein will likely be low. What other sequences are necessary in order to ensure optimal expression ... 

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