期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1974
卷号：71
期号：5
页码：1816-1818
DOI：10.1073/pnas.71.5.1816
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：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.
