Abstract
A genetic variation was found in liver esterase isozyme of the Japanese quail. The six phenotypes such as AA, BB, CC, AB, AC and BC were observed. It was clarified that these phenotypes were under control of three co-dominant alleles, Es-2A, Es-2B and Es-2c at the same locus located on the autosome. The gene frequency in Es-2 esterase isozyme of random-bred populations were estimated as very high for Es-2B (0.77-0.88) Iow for Es-2A (0.10-0.21) and the lowest for Es-2c (0.01-0.02). Es-2 esterase isozyme showed organ specificity and was found only in liver. Es-2 esterase isozyme first appeared on the day of hatching but its activity was very weak. The activity was clearly observed in all individuals at about five days of age, thereafter the activity increased gradually with age. At 15 days of age, the activity was approximately the same as that of the matured quail at about 40 days of age. It was also revealed that the liver esterase is an aliesterase in characteristics.
