VISUALIZATION OF GOLGI-APPARATUS IN METHACRYLATE EMBEDDED CONIFER EMBRYO TISSUE USING THE MONOCLONAL-ANTIBODY JIM-84

Methacrylate embedding followed by resin removal has been used for the first time to visualize a membrane-associated antigen at the tissue l evel. Monoclonal antibody JIM 84 was used to stain the Golgi apparatus of gymnosperm (conifer) embryos by light microscope immunocytochemist ry. Specificity of labelling was confirmed by electron microscope immu nocytochemistry using LR-white resin. GA staining was evident in all s tages of white spruce somatic embryo development from immature to matu re. Some regions of the somatic embryos (e.g. root cap/suspensor regio n) stained more vigorously than other regions (hypocotyl/cotyledon end ). GA also stained in roots of Monterey pine and Douglas fir. Unlike t he situation in most angiosperms, JIM 84 antigen appears to be absent from the conifer plasma membrane. However, it appears to be present in representatives of both major classes of higher plants. (C) 1997 Acad emic Press Limited.