Localization of type II collagen in the lingual mucosa of rats during the morphogenesis of circumvallate papillae

Abstract

Iwasaki, S., Aoyagi, H. and Yoshizawa, H. 2011. Localization of type II collagen in the lingual mucosa of rats during the morphogenesis of circumvallate papillae. —Acta Zoologica (Stockholm) 92: 67–74. Immunoreactivity specific for type II collagen was recognized first in the mesenchymal connective tissue just beneath the circumvallate papilla placode in fetuses on E13. At this stage, most of the lingual epithelium was pseudostratified epithelium composed of one or two layers of cuboidal cells. However, the epithelium of the circumvallate papilla placode was composed of several layers of cuboidal cells. Immunoreactivity specific for type II collagen was detected mainly on the lamina propria just beneath the lingual epithelium of the rudiment of the circumvallate papilla in fetuses on E15 and on E17, and slight immunostaining was detected on the lamina propria around the rudiment. In fetuses on E19, immunoreactivity specific for type II collagen was widely and densely distributed on the connective tissue around the developing circumvallate papillae and on the connective tissue that surrounded the lingual muscle. Immunoreactivity specific for type II collagen was sparsely distributed on the lamina propria of central bulge. After birth, morphogenesis of the circumvallate papillae advanced gradually with the increase in size of the tongue. Immunoreactivity specific for type II collagen was distinctively distributed in the lamina propria around circumvallate papilla, in the central bulge, and in the connective tissue that surrounded the lingual muscle.