Transposon-mediated mutations in the untranslated leader of maize Adh1 that increase and decrease pollen-specific gene expression.
AUTOR(ES)
Dawe, R K
RESUMO
The unstable mutation Adh1-Fm335 contains a Dissociation (Ds1) transposable element at position +53 in the untranslated leader of the maize Alcohol dehydrogenase-1 (Adh1) gene. Excision of Ds1 is known to generate new alleles with small additions and rearrangements of Adh1 DNA. We characterized 16 revertant alleles with respect to ADH1 activity levels in scutellum (nutritive tissue of the seed), anaerobic root, and pollen. Whereas gene expression was not different from the wild type in the sporophytic tissues of the scutellum and anaerobic root, there were strong allelic differences in pollen. One allele underexpressed pollen ADH1 at 48% of the wild-type level, and another overexpressed pollen ADH1 at 163% of the wild-type level. Quantitative RNase protection assays demonstrated that the mutant phenotypes reflected changes in the levels of steady state mRNA in pollen. These data provide a definitive demonstration of an overexpression mutant in plants and further show that marked increases in mRNA levels can follow minor alterations in central untranslated leader sequences. The nucleotide sequence of 12 new revertant alleles and the molecular mechanisms responsible for pollen-specific gene expression are discussed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=160272Documentos Relacionados
- A strong inhibitor of gene expression in the 5' untranslated region of the pollen-specific LAT59 gene to tomato.
- Characterization of a pollen-specific cDNA clone from Zea mays and its expression.
- Transposon-mediated chromosomal rearrangements and gene duplications in the formation of the maize R-r complex.
- The TATA box promoter region of maize Adh1 affects its organ-specific expression.
- Transposon-Mediated Single-Copy Gene Delivery Leads to Increased Transgene Expression Stability in Barley1