A. Ishizuyaoka et al., TRANSIENT EXPRESSION OF STROMELYSIN-3 MESSENGER-RNA IN THE AMPHIBIAN SMALL-INTESTINE DURING METAMORPHOSIS, Cell and tissue research, 283(2), 1996, pp. 325-329
It has been suggested that a matrix metalloproteinase, stromelysin-3 (
ST3), is an important enzyme for epithelial transformation; the ST3 ge
ne is known to be regulated by thyroid hormone during Xenopus metamorp
hosis. In this study, we have examined the distribution of ST3 mRNA in
the small intestine of Xenopus during metamorphosis by using in situ
hybridization. Around stage 58, ST3 mRNA is first detectable in larval
fibroblasts near the muscular layer, and then increases in amount thr
oughout the entire region of connective tissue. By stage 61, when conn
ective tissue cells are rapidly increasing in number, ST3 mRNA is loca
lized in fibroblasts just beneath the epithelium. This localization of
ST3 mRNA is in good temporal accordance with modification of the base
ment membrane and epithelial transformation from the larval to adult f
orm. Thereafter, ST3 mRNA gradually decreases and is no longer detecte
d after stage 63 when the adult epithelium has completely replaced the
larval type. The transient expression of ST3 mRNA in the fibroblasts
of connective tissue during metamorphosis indicates that it plays an i
mportant role in epithelial transformation by changing the basement me
mbrane.