Ontogenesis of serum esterases in Mus musculus

Abstract

Electrophoretic techniques by which mixtures of isoenzymes, and homologous proteins generally, may be resolved have become valuable tools in developmental biology. They make possible the study of development at the molecular level, in the sense that the differentiation of protein patterns underlies ontogenetic changes and tissue differences. The greater successes of this approach have been achieved, of course, in the fields of haemoglobin variation and of tissuespecific isoenzymes of lactic dehydrogenase (see Ingram, 1961; Markert & Ursprung, 1962). The work reported here concerns proteins characterized by their ability to catalyse the hydrolysis of esters. Their substrates range from carboxylic to aromatic esters, and there is a corresponding variety of esterases. It is usual, however, to find that each is effective, though to a different extent, on more than one form of esters. The overlap makes it legitimate, and in fact necessary, to study esterases as a group, although phosphatases are usually dealt with separately.