An investigation of lactate dehydrogenase activity in early amphibian development

The ontogeny of the enzyme LDH has been studied in two species of amphibians ( Amblystoma gracile and Rana aurora ) as it provides a sensitive gauge of the state of differentiation of the organism, since the number and proportions of LDH isozymes present exhibit temporal and species specificity, thereby reflecting the degree of activity of the controlling genes. The presence of LDH in all stages of both species examined was establishd by assaying embryo homogenates for LDH activity, and the LDH was resolved into isozymic patterns by the methods of starch gels and disc electrophoresis. Specific enzyme activity for each developmental stage was correlated with the developmental events then occurring and the isozyme patterns obtained were discussed in terms of an increase in complexity during Anuran ontogeny while an extension of the current LDH isozyme hypothesis was advanced to account for some of the Urodele experimental findings.