Proliferation in the gastric epithelium of bovine abomasum during foetal development as revealed by Ki-67 immunocytochemistry

For the first time, proliferative cells in the abomasal mucosa of 30 bovine foetuses with a crown-rump length of 34 to 1000 mm (approximately 45-250 d ays of gestation) were detected using the antibody MIB-1 against the (human ) nuclear-associated protein Ki-67. At the beginning of mucosal development , the epithelium is stratified and MIB-1 positive cells are scattered all o ver the epithelium. With the formation of gastric pit/gland invaginations. the proliferative cells are mostly confined to the basal half or third of t he gastric pit/gland unit, both in the regio glandulae propriae and in the regio glandulae pyloricae. From the 27th week in the regio glandulae propri ae and the 30th week in the pyloric gland region, respectively, the prolife rative cells move upwards and are situated in the bottom of the pit and the upper part of the gland, whereas the base of the gland is free of labellin g.