Polymorphic control of subunit synthesis for the enzyme lactate dehydrogenase in the newt,Triturus viridescens
✍ Scribed by Sherr, Charles J.
- Publisher
- John Wiley and Sons
- Year
- 1968
- Tongue
- English
- Weight
- 461 KB
- Volume
- 169
- Category
- Article
- ISSN
- 0022-104X
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✦ Synopsis
The newt, Triturus viridescens, shows a polymorphism for the genes controlling the synthesis of the enzyme lactate dehydrogenase (LDH). Homozygotes have either of two electrophoretically fast migrating bands. In heterozygotes, the isozymes present in both homozygote classes appear along with three additional isozymes of intermediate mobilities. An additional slowly migrating isozyme is found in all animals. The relationship between the three phenotypic distributions of isozymes in the population is consistent with the predicted phenotypic frequencies made in accordance with the Hardy-Weinberg Law. No difference in the Km for pyruvate reduction or the thermal denaturation characteristics was noted between homogenates containing different isozyme distributions. The electrophoretically fast moving isozymes in all homogenates are inactivated at a higher temperature than the slowly migrating isozyme. The evolutionary significance of polymorphism for alleles controlling isozyme synthesis is discussed.