Mucus vesicle formation in goblet cells lining the crypts.

<p>A) The goblet cells located in the middle crypt region show initial (1 h) TAMRA staining (red) in the Golgi apparatus where GalNAz was used in the biosynthesis of <i>O-</i>linked glycoproteins. Stained mature mucin vesicles can be observed after 5 h and the number of labeled vesicles increases up to 10 h after injection. Most of the labeled vesicles were secreted during 24 h, but a few remained. The TAMRA-stained sections and those combined with the Muc2 staining (green) as merged pictures are shown for all the indicated times. Scale bars are 5 µm. B) The TAMRA stained GlaNAz-containing mucin vesicle area of the theca in the crypt goblet cells is presented for samples labeled for 4, 7, 9 and 12 h. (mean±SEM). Most labeled stored mucins are observed after 9 h.