The Golgi body and thiamine pyrophosphatase localization in embryonic cells in culture

Chick embryo endoblast and segmented mesoderm cells were cultured and processed using the cytochemical technique for the detection of the enzyme thiamine pyrophosphatase. Reaction product was found in cisternae of the Golgi body and associated vesicles. Random, patchy distribution of deposit was observed on the dorsal surface of the monolayer cells and between overlapping processes, but not on the ventral surface which faces the substratum. Both cell types reacted similarly. The results suggest that new membrane of Golgi origin is formed at the dorsal but not the ventral surface of cells. There was no defined locus of insertion, at the tip of the advancing lamellipodia or elsewhere.