The development of the gonadal and immune systems in the Atlantic salmon (Salmo salar L.) and a consideration of the possibility of inducing autoimmune destruction of the testis

Abstract

Gonad development was studied histologically and morphologically in eggs and fry of Salmo salar L. First signs of gonad tissue were found 6 days prior to hatching. Sex differentiation of the gonads appeared to be complete by about 60 days post-hatch. The development of the lymphoid system was also studied. The thymus is the first organ to become lymphoid (22 days post-hatch). Membrane bound immunoglobulin M (mlgm) and Mixed Lymphocyte Reactivity (MLR) appeared simultaneously about 45 days post-hatching, coincident with the start of feeding.