Genetic control of urea resistant esterase of liver extracts in chicken.

Starch gel electrophoresis according to Okada & Sasaki (1970) revealed six regions of esterase activity designated I to VI. Further genetic variation was found in esterase region 111 in this study. Two phenotypes, A and 0, were observed by means of urea denaturation of chicken liver extracts. These were genetically controlled by an autosomal locus, designated as Es-9, with a Completely dominant (Es-9.4) and a completely recessive (Es-90) alleles. Es-9-4 was the most frequent allele in White Plymouth Rock, New Hampshire and Australorp strains and rare in White Leghorn strains.