Morphological differentiation of mitochondria in the early amphibian embryo

Three different cell types (epidermal cells, fibroblast-like Ruffini cells and undifferentiated cells) may be observed in cultures of cells isolated from the blastula of Ambystoma mexicanum. Electron micrographs show that the mitochondria in the two kinds of differentiated cells have the orthodox conformation; those in the undifferentiated cells the condensed conformation. Measurements of the area and the form factor demonstrate that the mitochondria in the differentiated cells are considerably larger than those in the undifferentiated cells, and that the three populations of mitochondria differ significantly from each other.