Genetic variation of pancreatic esterase isozyme in Japanese quail

A genetic variation was found in pancreatic esterases of Japanese quail which appeared to be arylesterase. It was found on the cathode side in the agar gel electrophoresis. Three phenotypes, A,B and AB, were observed. These phenotypes were shown to be controlled by one autosomal locus, designated as Es-4, with co-dominant alleles Es-4A and Es-4B. Es-4 esterase isozymes were detected in all the individuals from about 4 days of age, but the activity was very weak. However, it gradually increased to reach a level almost the same as that of a mature quail from about 15 days of age.