Abstract
All individuals of the diploid plant Clarkia franciscana, an annual species native to California, have duplicated genes for the dimeric enzyme alcohol dehydrogenase. Since each gene specifies a polypeptide with a distinct charge, the species has a fixed heterozygous phenotype consisting of three isozyme variants. The enzyme is coded by a single gene in closely related species. Clarkia franciscana is highly self-pollinated and monomorphic at all but one of its loci that have been examined. Consequently, the duplication provides enzyme variability in the absence of genetic variability.
Keywords: plant evolution, isozyme polymorphisms, electrophoresis
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- Fincham J. R. Heterozygous advantage as a likely general basis for enzyme polymorphisms. Heredity (Edinb) 1972 Jun;28(3):387–391. doi: 10.1038/hdy.1972.49. [DOI] [PubMed] [Google Scholar]
- Schwartz D., Endo T. Alcohol Dehydrogenase Polymorphism in Maize-simple and Compound Loci. Genetics. 1966 Apr;53(4):709–715. doi: 10.1093/genetics/53.4.709. [DOI] [PMC free article] [PubMed] [Google Scholar]