A genetic role of isozyme types in plasma alkaline phosphatase activity in the young chicken

A genetic role of isozyme types in plasma alkaline phosphatase (AP) activity within dam families in the young chicken was investigated in a White Plymouth Rock strain kept in our laboratory since 1961. Plasma samples were obtained at 32 and 56 days of age and subjected to horizontal polyacrylamide gel electrophoresis and two methods of analysis. A higher level of plasma AP activity of the fast (F) type relative to that of slow (S) type was re-confirmed. The F types of full-sib chicks had distinctly higher AP activity than the S types. Also within isozyme types, family differences were significant in the F type but not in the S type. The correlation of AP activities between 32 and 56 days of age was significant in the F type but not in the S type, which could be attributed to the effect of aging. The genetic control of plasma AP activity in young chickens were discussed under a hypothesis of two independent genetic systems, i.e. major genic and polygenic.