| A sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis procedure was developed. Proteins were visualized on 7.5% poly-acrylamide gels by staining with Coomassie brilliant blue. Relative mobility (R f) values were determined for the major subunits of seven marker proteins ranging from 130,000 to 14,300 in molecular weight. Molecular weights were determined from a plot of negative 100 logarithm of relative mobility versus molecular weight. Two studies were performed using this technique.;The soluble protein fractions of Xenopus laevis tail tissue during in vivo metamorphosis were studied. Between 20 and 24 different subunit proteins were resolved in protein samples from each stage studied: 45, 52-53, 57-58, 61-62, and 64. Prior to morphological signs of tail regression a new subunit protein was resolved.;Plasma proteins were studied during the ontogeny of the domestic chicken. A constant number of subunit proteins was resolved in the plasma of all ages studied (8, 11, 14, and 18 day embryos, newly hatched chicks, and adults). Relative quantitative increases and decreases in subunit proteins were observed between ages during ontogeny and maturation. A 17,000 subunit was resolved only in adult chicken plasma with the loss of the 14,300 subunit protein present in the plasma of all other ages studied. |
