Erythropoiesis during Amphibian Metamorphosis

Rabbit antibodies were prepared against the major hemoglobin components of the larval and adult stages of R. catesbeiana. The properties of the antisera were studied by double immunodiffusion, precipitation, and complement fixation. The antisera to tadpole and frog hemoglobins did not cross-react with either hemoglobin or apohemoglobin. The anti-serum against frog hemoglobin was used for the detection of frog hemoglobin in tadpoles undergoing either natural or thyroxine-induced metamorphosis. It was shown that frog hemoglobin is detectable first in the liver, indicating that the liver is the site of erythrocyte maturation during metamorphosis.