The Molecular Basis of Variation Affecting Gene Expression: Evidence from Studies on the Ribosmal RNA Gene Loci of Wheat
A question relevant to an understanding of plant breeding is “What is the molecular basis of allelic variation affecting gene expression?”. The importance of this question is elevated if one accepts the perhaps biased belief that much of the important variation that plant breeders exploit is concerned with variation in the amounts of gene products in time and space during plant development. Many other relevant questions emerge when one wonders about variation in gene expression. For example, does a gene adopt a different structure when it is active compared with when it is silent? How does a plant turn a gene off and on? What kinds of mutations cause a gene to be more or less active.
KeywordsCytosine Methylation rDNA Locus Hypersensitive Site CCGG Site Unmethylated Cytosine
Unable to display preview. Download preview PDF.
- Flavell, R.B., 1986, The structure and control of expression of ribosomal RNA genes, Oxford Surveys of Plant Molecular and Cell Biology, 3: 251–274.Google Scholar
- Flavell, R.B., 1989, Variation in structure and expression of ribosomal DNA loci in wheat, Genome, in press.Google Scholar
- Miller, K.G., Tower, J., and Sollner Webb, B., 1985, A complex control region of the mouse rRNA gene directs accurate initiation by RNA polymerase I, Mol. and Cell. Biol, 5: 554–562.Google Scholar