The systematic value of creatine kinase expression in reptiles

Isozyme characters of creatine kinase, including the number of genes, the s pecificity of tissue expression, and the ability to form interlocus and int ralocus heterodimers, were reevaluated for their potential for systematics applications among the reptiles. The gene number character has limited appl ication because it is apomorphic only for chelid turtles. The intralocus he terodimer formation character has limited systematic value because of the i nfrequency of heterozygosity. Likewise, the interlocus heterodimer formatio n character has limited systematic value because of the infrequency of both Ck-A and Ck-C products being expressed in the same tissue. Differences in patterns of specificity of tissue expression hold the greatest potential fo r applications in reptilian systematics. (C) 1999 Published by Elsevier Sci ence Ltd. All rights Reserved.