Abstract
Mutator stocks of maize produce mutants at many loci at rates 20- to 50-fold above spontaneous levels. Current evidence suggests that this high mutation rate is mediated by an active transposable element system, Mu. Members of this transposable element family are found in ∼10–60 copies in Mutator stocks. We report here an initial characterization of previously undetected sequences homologous to Mu elements in eight non-Mutator inbred lines and varieties of maize that have a normal low mutation rate. All stocks have ∼40 copies of sequences homologous only to the terminal repeat and show weak homology to an internal probe. In addition, several of the stocks contain an intact Mu element. One intact Mu element and two terminal-specific clones have been isolated from one non-Mutator line, B37. The cloned sequences have been used to demonstrate that in genomic DNA the intact element, termed Mu1.4B37, is modified, such that restriction sites in its termini are not accessible to cleavage by the HinfI restriction enzyme. This modification is similar to that observed in Mutator lines that have lost activity. We hypothesize that the DNA modification of the Mu-like element may contribute to the lack of Mutator activity in B37.
Full Text
The Full Text of this article is available as a PDF (3.2 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Alleman M., Freeling M. The Mu transposable elements of maize: evidence for transposition and copy number regulation during development. Genetics. 1986 Jan;112(1):107–119. doi: 10.1093/genetics/112.1.107. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Barker R. F., Thompson D. V., Talbot D. R., Swanson J., Bennetzen J. L. Nucleotide sequence of the maize transposable element Mul. Nucleic Acids Res. 1984 Aug 10;12(15):5955–5967. doi: 10.1093/nar/12.15.5955. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bennetzen J. L., Swanson J., Taylor W. C., Freeling M. DNA insertion in the first intron of maize Adh1 affects message levels: cloning of progenitor and mutant Adh1 alleles. Proc Natl Acad Sci U S A. 1984 Jul;81(13):4125–4128. doi: 10.1073/pnas.81.13.4125. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bennetzen J. L. Transposable element Mu1 is found in multiple copies only in Robertson's Mutator maize lines. J Mol Appl Genet. 1984;2(6):519–524. [PubMed] [Google Scholar]
- Bingham P. M., Kidwell M. G., Rubin G. M. The molecular basis of P-M hybrid dysgenesis: the role of the P element, a P-strain-specific transposon family. Cell. 1982 Jul;29(3):995–1004. doi: 10.1016/0092-8674(82)90463-9. [DOI] [PubMed] [Google Scholar]
- Chandler V. L., Walbot V. DNA modification of a maize transposable element correlates with loss of activity. Proc Natl Acad Sci U S A. 1986 Mar;83(6):1767–1771. doi: 10.1073/pnas.83.6.1767. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Döring H. P., Tillmann E., Starlinger P. DNA sequence of the maize transposable element Dissociation. Nature. 1984 Jan 12;307(5947):127–130. doi: 10.1038/307127a0. [DOI] [PubMed] [Google Scholar]
- Englund P. T. Analysis of nucleotide sequences at 3' termini of duplex deoxyribonucleic acid with the use of the T4 deoxyribonucleic acid polymerase. J Biol Chem. 1971 May 25;246(10):3269–3276. [PubMed] [Google Scholar]
- Fedoroff N., Wessler S., Shure M. Isolation of the transposable maize controlling elements Ac and Ds. Cell. 1983 Nov;35(1):235–242. doi: 10.1016/0092-8674(83)90226-x. [DOI] [PubMed] [Google Scholar]
- Galbraith D. W., Harkins K. R., Maddox J. M., Ayres N. M., Sharma D. P., Firoozabady E. Rapid flow cytometric analysis of the cell cycle in intact plant tissues. Science. 1983 Jun 3;220(4601):1049–1051. doi: 10.1126/science.220.4601.1049. [DOI] [PubMed] [Google Scholar]
- Hohn B. In vitro packaging of lambda and cosmid DNA. Methods Enzymol. 1979;68:299–309. doi: 10.1016/0076-6879(79)68021-7. [DOI] [PubMed] [Google Scholar]
- Kidwell M. G., Kidwell J. F., Sved J. A. Hybrid Dysgenesis in DROSOPHILA MELANOGASTER: A Syndrome of Aberrant Traits Including Mutation, Sterility and Male Recombination. Genetics. 1977 Aug;86(4):813–833. doi: 10.1093/genetics/86.4.813. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mullins J. I., Brody D. S., Binari R. C., Jr, Cotter S. M. Viral transduction of c-myc gene in naturally occurring feline leukaemias. 1984 Apr 26-May 2Nature. 308(5962):856–858. doi: 10.1038/308856a0. [DOI] [PubMed] [Google Scholar]
- Neal M. W., Florini J. R. A rapid method for desalting small volumes of solution. Anal Biochem. 1973 Sep;55(1):328–330. doi: 10.1016/0003-2697(73)90325-4. [DOI] [PubMed] [Google Scholar]
- O'Reilly C., Shepherd N. S., Pereira A., Schwarz-Sommer Z., Bertram I., Robertson D. S., Peterson P. A., Saedler H. Molecular cloning of the a1 locus of Zea mays using the transposable elements En and Mu1. EMBO J. 1985 Apr;4(4):877–882. doi: 10.1002/j.1460-2075.1985.tb03713.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rivin C. J., Cullis C. A., Walbot V. Evaluating quantitative variation in the genome of Zea mays. Genetics. 1986 Aug;113(4):1009–1019. doi: 10.1093/genetics/113.4.1009. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schwarz-Sommer Z., Gierl A., Cuypers H., Peterson P. A., Saedler H. Plant transposable elements generate the DNA sequence diversity needed in evolution. EMBO J. 1985 Mar;4(3):591–597. doi: 10.1002/j.1460-2075.1985.tb03671.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Southern E. M. Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol. 1975 Nov 5;98(3):503–517. doi: 10.1016/s0022-2836(75)80083-0. [DOI] [PubMed] [Google Scholar]
- Vieira J., Messing J. The pUC plasmids, an M13mp7-derived system for insertion mutagenesis and sequencing with synthetic universal primers. Gene. 1982 Oct;19(3):259–268. doi: 10.1016/0378-1119(82)90015-4. [DOI] [PubMed] [Google Scholar]