Cytochemical and Immunocytochemical Study on the Cellulase Activity in the Digestive Tract of the Land Snail Nesiohelix

동양달팽이 Nesiohelix samarangae 소화관에서의 cellulase 활성에 대한 세포화학적 및 면역세포화학적 연구

In order to observe the anticellulolytic localization in the epithelia of the digestive tract such as esophagus, crop, and intestine of a Korean land snail N. samarangae, a cytochemical method and a immunogold labelling method were applied. For the cytochemical study on the cellulase activity, Benedict reaction method applied. And for the immunocytochemical study, the rabbit serum immunoglobuins (IgG) was obtained from the rabbits injected with cellulase which was extracted from body fluid of the snail. The digestive tract tissues of N. samarangae were fixed with 4% paraformaldehyde and 2% OsO4 and embedded in Lowicryl K4M at -40$^{\circ}C$ under UV light (360 nm). The thin sections were loaded on the nickel grids and stained with the serum IgG and protein A-gold complex (particle size: 10 nm). Observations were undertaken with transmission electron microscope (Jeol, JEM-1010). The epithelium of the digestive tract was consisted of five types of cells. In the cytochemical study, the reaction products were found along the periphery of the vacuoles derived from the Bebedict reaction. In the immunocytochemical study, the protein-A gold particles were selectively labelled in Type 1, Type 3 and Type 4 cells in intestinal tissue. membranes of rER, in the surrounding cytoplasm of the rER and secretory granules, and in the apical cytoplasm of the cells. On the material being secreted from the apical cytoplasm was also labelled with the immunogold particles. The all results obtained throughtout present study suggest that the intestinal epithelium of the snail N. samarangae seretes cellulase as one of digestive enzymes.