Serum Proteins and Antibody Production in Rainbow Trout (<i>Salmo gairdneri</i>)

Abstract

Rainbow trout serum was shown to be made up of three major protein components. These three major components did not coincide by electrophoretic mobility or by relative salt solubility with the classic albumin, α-, β-, and γ-globulin separation of the sera of higher animals. A component equivalent to γ-globulin of higher animals was found to be completely lacking in the sera of both immunized and non-immunized rainbow trout.Specific humoral antibodies in rainbow trout immune sera were found to be contained in the electrophoretically least mobile proteins. These proteins coincided most nearly to the β-globulins and possibly the least electrophoretically mobile α-globulins of higher animals. Salt solubility of the serum proteins containing the specific antibody assisted in this conclusion. The electrophoretically least mobile major serum protein components were found to contain all of the antibody activity. These proteins could be removed from immune serum by 20% sodium sulfate. The assumption was made that Aeromonas hydrophila antibodies in immunized rainbow trout blood serum may be made up of a complex of serum proteins with a broad range of salt solubility and electrophoretic mobilities.Serum proteins of rainbow trout could also be classified as euglobulins or pseudoglobulins. The serum proteins which contained the A. hydrophila antibodies were found to be euglobulins.