Intron-mediated enhancement of heterologous gene expression in maize
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Chimeric genes containing the coding sequence for bacterial chloramphenicol acetyl transferase (CAT) have been introduced by electroporation into maize protoplasts (Black Mexican Sweet) and transient expression monitored by enzyme assays. Levels of CAT expression were enhanced 12-fold and 20-fold respectively by the inclusion of maize alcohol dehydrogenase-1 introns 2 and 6 in the chimeric construct. This enhancement was seen when the intron was placed within the 5′ translated region but not when it was located upstream of the promoter or within the 3′ untranslated region. Deletion of exon sequences adjacent to intron 2 abolished its ability to mediate enhancement of CAT gene expression. Northern analysis of protoplasts electroporated with intron constructs revealed elevated levels of CAT mRNA. However, this elevation was insufficient to account for the increased enzyme activity. One explanation of these results is that splicing affects both the quantity of mRNA.
Key wordsAdh1 chloramphenicol acetyl transferase enhancer intron maize transient expression
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- 1.Barker RF, Idler KB, Thompson DV, Kemp JD: Nucleotide sequence of the T-DNA region from the Agrobacterium tumefaciens octopine Ti plasmid pTI15955. Plant Mol Biol 2: 335–350 (1983).Google Scholar
- 4.DeGreve H, Dhaese P, Seurinck J, Lemmers M, Van Montagu M, Schell J: Nucleotide sequence and transcript map of the Agrobacterium tumefaciens Ti plasmidencoded octopine synthase gene. J Mol Appl Genet 1: 499–511 (1983).Google Scholar
- 13.Hohn T, Richards K, Lebeurier G: Cauliflower Mosaic Virus on its way to becoming a useful plant vector. Curr Top Microbiol Immunol 96: 193–236 (1982).Google Scholar
- 14.Pierce DA, Mettler IJ, Lachmansingh AR, Pomeroy LM, Weck EA, Mascarenhas D: Effect of 35S leader modifications on promoter activity. In: UCLA Symp Mol Cell Biol, New Series vol. 62 pp. 301–310 Alan R. Liss, New York (1987).Google Scholar