Control mechanisms of the conversion from synthesis of embryonic to adult hemoglobin

ERYTHROPOIESIS DURING AMPHIBIAN METAMORPHOSIS : III. Immunochemical Detection of Tadpole and Frog Hemoglobins (Rana catesbeiana) in Single Erythrocytes

Rabbit antibodies specific for the major tadpole and frog hemoglobin components of R. catesbeiana were used for the detection of the two hemoglobins inside single cells. The antisera, after fractionation by ammonium sulfate precipitation and diethylaminoethyl (DEAE)-cellulose chromatography, were conjugated with fluorescein isothiocyanate for the antifrog hemoglobin serum and tetramethylrhodamine isothiocyanate for the antitadpole hemoglobin serum. The conjugated fractions, refractionated by stepwise elution from a DEAE-cellulose column, were used for the fluorescent staining of blood smears, liver tissue imprints, and smears of liver cell suspensions. Both simultaneous and sequential staining with the two fluorescent preparations indicated that larval and adult hemoglobins were not present within the same erythrocyte during metamorphosis. In other experiments, erythroid cells from animals in metamorphosis were spread on agar containing specific antiserum. Precipitates were formed around the cells which contain the particular hemoglobin. The percentages of cells containing either tadpole or frog hemoglobin were estimated within the experimental error of the method. The data showed that the two hemoglobins are in different cells. It is concluded that the hemoglobin change observed during the metamorphosis of R. catesbeiana is due to the appearance of a new population of erythroid cells containing exclusively frog hemoglobin.

Hemoglobin A and B of the cat: occurrence in the same cell

The two major hemoglobins found in domestic cat blood occur within the same erythrocyte. A putative asymmetrical hybrid, alpha2betaAbetaB, is shown to be present in the cell by isoelectric focusing.

Electrophoretic analysis of hemoglobin and isozymes in individual vertebrate cells

Electrophoretic patterns of enzymes in single vertebrate erythrocytes may be visualized with the use of capillary tube polyacrylamide columns and stains which amplify the enzymatic activity. The following points have thereby been demonstrated:1. Peripheral blood of metamorphosing bullfrogs (Rana catesbeiana) contains two molecular forms of hemoglobin: embryonic (tadpole) and adult (frog). Only one of these forms is found in each erythrocyte.2. Human umbilical cord blood contains fetal and adult hemoglobins; both forms may be found in individual erythrocytes, in varying proportions.3. Both lactate dehydrogenase isozymes found in whole blood of bullfrogs and humans are found in individual erythrocytes, but the proportions differ from cell to cell.