Molecular genetics of avian proteins—IV. The egg-white proteins of the golden pheasant, Chrysolophus pictus L., and Lady Amherst's pheasant, C. amherstiae leadbeater, and their possible evolutionary significance

Abstract

1. 1. Egg whites from twenty-two Golden pheasants and ten Lady Amherst's pheasants have been compared by vertical starch-gel electrophoresis. The electrophoresis patterns obtained from Chrysolophus egg white were different from the electrophoretic pattern of egg white from any of the other species of galliform birds examined, including five other species of pheasants. It was not possible to differentiate between the two species of Chrysolophus using the electrophoretic patterns of egg white as a criterion. 2. 2. In the present study Chrysolophus egg white was resolved into sixteen components. Histochemical techniques and partial purification of egg white by salting out with ammonium sulphate led to the identification of “catalase”, esterase, conalbumin, the globulin fraction and the albumin fraction. 3. 3. Individual variation, common to both species, was seen in several fractions. 4. 4. The variation in the albumin fraction fall into three categories: a fast type, a slow typed and third type comprising the components of both fast and slow types. Observation of the three types in several buffer systems confirmed that each type was a real and not an artefact caused by pH, gel texture or other factors. 5. 5. It is suggested that each type is the phenotypic expression of a different genotype, the fast and slow types being homozygotes and the composite type the heterozygote. 6. 6. Some of the evolutionary implications of the above findings are discussed.