Three-dimensional visualization of the Golgi apparatus: Observation of Brunner's gland cells by a confocal laser scanning microscope

The three-dimensional structure of the Golgi apparatus in cells of the Brun ner's gland in the mouse was observed by using a confocal laser scanning mi croscope. Two lectins, FITC-labeled soybean agglutinin and Texas red-labele d Griffonia simplicifolia agglutinin II, were used to visualize the whole G olgi apparatus. Staining with the former lectin, which has been known to la bel the cis-stacks, showed a lacy dome-like structure situated in the supra nuclear region. Staining with the latter lectin, known to label the interme diate-to-trans-stacks and the secretory granules, showed a dome-like struct ure consisting of network and cobblestone-like patterns in the same region and also granular stainings near the surface of the cobblestone-like patter ns and the apical region of a cell. Double-staining demonstrated that the s oybean agglutinin-labeled network always surrounded the G. simplicifolia ag glutinin II-stained structure, Based on these observations, we propose a ne w three-dimensional model of the Golgi apparatus: it forms a dome-like stru cture over a nucleus, a network of cis-stacks forms its outer boundary, and this outer boundary is lined and paved with successive intermediate and tr ansstacks. It is thought that secretory granules are released toward the in ternal space of the Gels apparatus and transported to the apical cytoplasm through the holes of the network. (C) 1999 Academic Press.