Intron-mediated enhancement of heterologous gene expression in maize

• Published in: Plant molecular biology 1990-12, Vol.15 (6), p.913-920
• Main Authors: Mascarenhas, D. (Sandoz Crop Protection, Palo Alto, CA (USA)), Mettler, I.J, Pierce, D.A, Lowe, H.W
• Format: Article
• Language: English
• Subjects: Alcohol Dehydrogenase - genetics; Bacterial Proteins - genetics; Base Sequence; Biological and medical sciences; Chloramphenicol O-Acetyltransferase - biosynthesis; Chloramphenicol O-Acetyltransferase - genetics; DNA - genetics; EXPRESION GENICA; EXPRESSION DES GENES; Fundamental and applied biological sciences. Psychology; GENE EXPRESSION; Gene Expression Regulation; Genes, Bacterial; Genes, Plant; Genes, Synthetic; Genetic Vectors; Introns; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Plant Proteins - genetics; Recombinant Fusion Proteins - biosynthesis; Recombinant Fusion Proteins - genetics; Regulatory Sequences, Nucleic Acid; Transformation, Genetic; ZEA MAYS; Zea mays - genetics
• ISSN: 0167-4412; 1573-5028
• DOI: 10.1007/BF00039430

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 and quality of mRNA.