Summary
The relationship between rRNA gene dosage, rRNA synthesis and various phenotypic characters was studied in environmentally induced phenotypically and genetically distinct flax lines. Large (L) and small (S) types had 2210 and 1110 rRNA genes respectively, assessed by rRNA/DNA hybridization. The mean fresh weight of mature L and S plants was 165 g and 98 g, respectively. Root growth rates were linear during the first five days after germination, showing a mean value of 1·35 cm/day for L and 0·77 cm/day for S. Accumulation of RNA showed a parallel difference with 2·46 µg/day in L and 1·48 µg/day in S. At two-three days after germination the rate of synthesis of RNA (assessed by either (32P)-orthophosphate incorporation or by (3H)-adenosine incorporation and measurement of the specific activity of the ATP pools by the luciferin/luciferase assay) was not significantly different between L and S types. However Polyacrylamide gel electrophoretic analysis of the (32P)-rRNA indicated a 25 per cent greater proportion of RNA synthesis devoted to production of pre-rRNA in L compared with S types. In addition there is evidence of more efficient processing of the pre-rRNA in S types but greater stability of the mature rRNAs of L lines. These post-transcriptional controls appear to be mainly responsible for the greater accumulation of rRNA in phenotypically large types. The rRNA gene number changes and corresponding changes in transcription of pre-rRNA appear to be relatively unimportant in regulating the accumulation of rRNA.
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Bennett, M D, and Smith, J B. 1976. Nuclear DNA amounts in angiosperme. Phil Trans Roy Soc London B, 274, 227–274.
Bird, A P. 1978. Use of restriction enzymes to study eukaryotic DNA methylation: the symmetry of methylated sites supports semiconservative copying of the methylated pattern. J Mol Biol 118, 49–60.
Cullis, C A. 1976. Environmentally induced changes in ribosomal RNA cistron number in flax. Heredity, 36, 73–79.
Cullis, C A. 1977. Molecular aspects of the environmental induction of heritable changes in flax. Heredity, 38, 129–154.
Cullis, C A. 1979. Quantitative variation of rRNA genes in flax genotrophs. Heredity, 42, 237–246.
Durrant, A. 1958. Environmental conditioning of flax. Nature, 181, 928–929.
Durrant, A. 1962a. The environmental induction of heritable changes in Linum. Heredity, 17, 27–61.
Durrant, A. 1962b. Induction, reversion and epitrophism of flax genotrophs. Nature, 204, 1302–1304.
Durrant, A. 1971. Induction of growth of flax genotrophs. Heredity, 27, 277–298.
Durrant, A, and Jones, T W A. 1971. Reversion of induced changes in amount of nuclear DNA in Linum. Heredity, 27, 431–439.
Durrant, A, and Timmis, J N. 1973. Genetic control of environmentally induced changes in Linum. Heredity, 30, 369–379.
Evans, G M, Durrant, A, and Rees, H. 1966. Associated nuclear changes in the induction of flax genotrophs. Nature, 212, 697–699.
Flavell, R B, and O'Dell, M. 1979. The genetic control of nucleolus formation in wheat. Chromosoma (Berl), 71, 135–152.
Frankham, R. 1977. Environmentally induced changes in rRNA cistron number: purported lack of correlation with phenotype. Heredity, 39, 175.
Franz, G, and Kunz, W. 1981. Intervening sequences in ribosomal RNA genes and bobbed phenotype in Drosophila hydei. Nature, 292, 638–640.
Givens, J F, and Phillips, R L. 1976. The nucleolus organizer region of maize (Zea mays L.). Ribosomal RNA gene distribution and nucleolar interactions. Chromosoma (Berl), 57, 103–117.
Humphreys, T. 1973. Quantitative measurement of RNA synthesis. In Chrispeeles, M. J. (ed.) Molecular techniques and approaches in developmental biology, Wiley & Sons, pp. 141–163.
Ingle, J, Timmis, J N, and Sinclair, J. 1975. The relationship between satellite DNA, ribosomal RNA gene redundancy and genome size in plants. Plant Physiol, 55, 496–501.
Jackson, M, and Ingle, J. 1973. The interpretation of studies on rapidly labelled RNA in higher plants. Plant Physiol, 51, 412–414.
Joarder, I O, Al-Saheal, Y, Begum, J, and Durrant, A. 1975. Environments inducing changes in amount of DNA in flax. Heredity, 34, 247–253.
Long, E O, and Dawid, I B. 1979. Expression of ribosomal DNA insertions in Drosophila melanogaster. Cell, 18, 1185–1196.
Parish, J H, and Kirby, K S. 1966. Reagents which reduce interactions between ribosomal RNA and rapidly labelled RNA from rat liver. Biochim Biophys Acta, 129, 554–562.
Ritossa, F M, Atwood, K C, and Spiegelman, S. 1966. A molecular explanation of the bobbed mutants of Drosophila as partial deficiencies of ribosomal DNA. Genetics, 54, 819–834.
Schweizer, D. 1980. Fluorescent chromosome banding in plants; applications, mechanisms, and implications for chromosome structure. In Davies, D. R., and Hopwood, D. A. (eds.) The Plant Genome, John Innes Charity, pp. 61–72.
Scott, N S, and Ingle, J. 1973. The genes for cytoplasmic ribosomal RNA in higher plants. Plant Physiol, 51, 677–684.
Shermoen, A W, and Kiefer, B I. 1975. Regulation in rDNA-deficient Drosophila melanogaster. Cell, 4, 275–280.
Timmis, J N, and Ingle, J. 1973. Environmentally induced changes in rRNA gene redundancy. Nature New Biol, 244, 235–236.
Timmis, J N, and Ingle, J. 1975a. The status of ribosomal RNA genes during nuclear DNA reversion in flax. Biochem Genetics, 13, 629–634.
Timmis, J N, and Ingle, J. 1975b. Quantitative regulation of gene activity in plants. Plant Physiol, 56, 255–258.
Timmis, J N, Sinclair, J, and Ingle, J. 1972. Ribosomal RNA genes in euploids and aneuploids of hyacinth. Cell Differentiation, 1, 335–339.
Weinmann, R. 1972. Regulation of rRNA and 5S RNA synthesis in Drosophila melanogaster bobbed mutants. Genetics, 72, 267–276.
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Ghogain, N., Byrne, H. & Timmis, J. The genetic control of ribosomal RNA accumulation in flax genotrophs. Heredity 48, 211–226 (1982). https://doi.org/10.1038/hdy.1982.27
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DOI: https://doi.org/10.1038/hdy.1982.27
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