Abstract
We designate a region of the alcohol dehydrogenase locus (Adh) of the weedy crucifer, Arabidopsis thaliana, as ``hypervariable'' on the basis of a comparison of sequences from ecotypes Columbia and Landsberg. We found eight synonymous and two replacement mutations in the first 262 nucleotides of exon 4, and an additional two mutations in the contiguous region of intron 3. The rest of the sequence (2611 bp) has just three mutations, all of them confined to noncoding regions. Our survey of the hypervariable region among 37 ecotypes of A. thaliana revealed two predominant haplotypes, corresponding to the Columbia and Landsberg sequences. We identified five additional haplotypes and 4 additional segregating sites. The lack of haplotype diversity is presumably in part a function of low rates of recombination between haplotypes conferred by A. thaliana's tendency to self-fertilize. However, an analysis in 32 ecotypes of 12 genome-wide polymorphic markers distinguishing Columbia and Landsberg ecotypes indicated levels of outcrossing sufficient at least to erode linkage disequilibrium between dispersed markers. We discuss possible evolutionary explanations for the coupled observation of marked divergence within the hypervariable region and a lack of haplotype diversity among ecotypes. The sequence of the region for closely related species argues against the possibility that one allele is the product of introgression. We note (1) that several loss of function mutations (both naturally and chemically induced) map to the hypervariable region, and (2) the presence of two amino acid replacement polymorphisms, one of which causes the mobility difference between the two major classes of A. thaliana Adh electrophoretic alleles. We argue that protein polymorphism in such a functionally significant part of the molecule may be subject to balancing selection. The observed pattern of extensive divergence between the alleles is consistent with this explanation because balancing selection on a particular site maintains linked neutral polymorphisms at intermediate frequencies.
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- Berry A. J., Ajioka J. W., Kreitman M. Lack of polymorphism on the Drosophila fourth chromosome resulting from selection. Genetics. 1991 Dec;129(4):1111–1117. doi: 10.1093/genetics/129.4.1111. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Biol M. C., Lenoir D., Hugueny I., Louisot P. Hormonal regulation of glycosylation process in rat small intestine: responsiveness of fucosyl-transferase activity to hydrocortisone during the suckling period, unresponsiveness after weaning. Biochim Biophys Acta. 1992 Jan 13;1133(2):206–212. doi: 10.1016/0167-4889(92)90070-r. [DOI] [PubMed] [Google Scholar]
- Brändén C. I., Eklund H., Nordström B., Boiwe T., Söderlund G., Zeppezauer E., Ohlsson I., Akeson A. Structure of liver alcohol dehydrogenase at 2.9-angstrom resolution. Proc Natl Acad Sci U S A. 1973 Aug;70(8):2439–2442. doi: 10.1073/pnas.70.8.2439. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chang C., Meyerowitz E. M. Molecular cloning and DNA sequence of the Arabidopsis thaliana alcohol dehydrogenase gene. Proc Natl Acad Sci U S A. 1986 Mar;83(5):1408–1412. doi: 10.1073/pnas.83.5.1408. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Charlesworth B., Morgan M. T., Charlesworth D. The effect of deleterious mutations on neutral molecular variation. Genetics. 1993 Aug;134(4):1289–1303. doi: 10.1093/genetics/134.4.1289. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dennis E. S., Gerlach W. L., Pryor A. J., Bennetzen J. L., Inglis A., Llewellyn D., Sachs M. M., Ferl R. J., Peacock W. J. Molecular analysis of the alcohol dehydrogenase (Adh1) gene of maize. Nucleic Acids Res. 1984 May 11;12(9):3983–4000. doi: 10.1093/nar/12.9.3983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dolferus R., Van den Bossche D., Jacobs M. Sequence analysis of two null-mutant alleles of the single Arabidopsis Adh locus. Mol Gen Genet. 1990 Nov;224(2):297–302. doi: 10.1007/BF00271565. [DOI] [PubMed] [Google Scholar]
- Eklund H., Nordström B., Zeppezauer E., Söderlund G., Ohlsson I., Boiwe T., Söderberg B. O., Tapia O., Brändén C. I., Akeson A. Three-dimensional structure of horse liver alcohol dehydrogenase at 2-4 A resolution. J Mol Biol. 1976 Mar 25;102(1):27–59. doi: 10.1016/0022-2836(76)90072-3. [DOI] [PubMed] [Google Scholar]
- Feinbaum R. L., Ausubel F. M. Transcriptional regulation of the Arabidopsis thaliana chalcone synthase gene. Mol Cell Biol. 1988 May;8(5):1985–1992. doi: 10.1128/mcb.8.5.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fu Y. X., Li W. H. Statistical tests of neutrality of mutations. Genetics. 1993 Mar;133(3):693–709. doi: 10.1093/genetics/133.3.693. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hudson R. R., Kaplan N. L. The coalescent process in models with selection and recombination. Genetics. 1988 Nov;120(3):831–840. doi: 10.1093/genetics/120.3.831. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hudson R. R., Kreitman M., Aguadé M. A test of neutral molecular evolution based on nucleotide data. Genetics. 1987 May;116(1):153–159. doi: 10.1093/genetics/116.1.153. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jarillo J. A., Leyva A., Salinas J., Martinez-Zapater J. M. Low Temperature Induces the Accumulation of Alcohol Dehydrogenase mRNA in Arabidopsis thaliana, a Chilling-Tolerant Plant. Plant Physiol. 1993 Mar;101(3):833–837. doi: 10.1104/pp.101.3.833. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Konieczny A., Ausubel F. M. A procedure for mapping Arabidopsis mutations using co-dominant ecotype-specific PCR-based markers. Plant J. 1993 Aug;4(2):403–410. doi: 10.1046/j.1365-313x.1993.04020403.x. [DOI] [PubMed] [Google Scholar]
- Kreitman M. E., Aguadé M. Excess polymorphism at the Adh locus in Drosophila melanogaster. Genetics. 1986 Sep;114(1):93–110. doi: 10.1093/genetics/114.1.93. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lewontin R C. The Interaction of Selection and Linkage. I. General Considerations; Heterotic Models. Genetics. 1964 Jan;49(1):49–67. doi: 10.1093/genetics/49.1.49. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Macarthur R. H. ON THE RELATIVE ABUNDANCE OF BIRD SPECIES. Proc Natl Acad Sci U S A. 1957 Mar 15;43(3):293–295. doi: 10.1073/pnas.43.3.293. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McDonald J. H., Kreitman M. Adaptive protein evolution at the Adh locus in Drosophila. Nature. 1991 Jun 20;351(6328):652–654. doi: 10.1038/351652a0. [DOI] [PubMed] [Google Scholar]
- Milkman R. Electrophoretic variation in Escherichia coli from natural sources. Science. 1973 Dec 7;182(4116):1024–1026. doi: 10.1126/science.182.4116.1024. [DOI] [PubMed] [Google Scholar]
- Nam H. G., Giraudat J., Den Boer B., Moonan F., Loos WDB., Hauge B. M., Goodman H. M. Restriction Fragment Length Polymorphism Linkage Map of Arabidopsis thaliana. Plant Cell. 1989 Jul;1(7):699–705. doi: 10.1105/tpc.1.7.699. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sachs M. M., Freeling M., Okimoto R. The anaerobic proteins of maize. Cell. 1980 Jul;20(3):761–767. doi: 10.1016/0092-8674(80)90322-0. [DOI] [PubMed] [Google Scholar]
- Shih M. C., Heinrich P., Goodman H. M. Cloning and chromosomal mapping of nuclear genes encoding chloroplast and cytosolic glyceraldehyde-3-phosphate-dehydrogenase from Arabidopsis thaliana. Gene. 1991 Aug 15;104(2):133–138. doi: 10.1016/0378-1119(91)90242-4. [DOI] [PubMed] [Google Scholar]
- Strobeck C. Expected linkage disequilibrium for a neutral locus linked to a chromosomal arrangement. Genetics. 1983 Mar;103(3):545–555. doi: 10.1093/genetics/103.3.545. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Thomas B. R., Ford V. S., Pichersky E., Gottlieb L. D. Molecular characterization of duplicate cytosolic phosphoglucose isomerase genes in Clarkia and comparison to the single gene in Arabidopsis. Genetics. 1993 Nov;135(3):895–905. doi: 10.1093/genetics/135.3.895. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yokoyama S., Harry D. E. Molecular phylogeny and evolutionary rates of alcohol dehydrogenases in vertebrates and plants. Mol Biol Evol. 1993 Nov;10(6):1215–1226. doi: 10.1093/oxfordjournals.molbev.a040073. [DOI] [PubMed] [Google Scholar]