Jf. Beaulieu et al., RELATIONSHIP BETWEEN TENASCIN AND ALPHA-SMOOTH MUSCLE ACTIN EXPRESSION IN THE DEVELOPING HUMAN SMALL-INTESTINAL MUCOSA, Anatomy and embryology, 188(2), 1993, pp. 149-158
The expression of tenascin (Tn) and alpha-smooth muscle actin (alpha-S
MA) was analyzed in the developing and adult human small intestine by
means of double immunofluorescent staining with specific antibodies. B
y 7 weeks of gestation, the gut anlage has a simple tubular shape and
is formed of a stratified undifferentiated epithelium surrounded by a
poorly organized mesenchyme. Both Tn and alpha-SMA were found exclusiv
ely at the periphery of the tissue, corresponding to the presumptive m
uscularis propria. By 9 weeks, villus rudiments had formed but Tn and
alpha-SMA remained restricted to the muscularis propria. Tn was first
detected in the mesenchyme at 11 weeks. By 13 weeks, a preferential di
stribution of Tn in the subepithelial region of the mesenchyme was rea
dily observed while alpha-SMA was still absent. From this stage to 20
weeks, Tn gradually concentrated in this region that, as determined by
alpha-SMA detection, corresponded to the future muscularis mucosa are
a. As shown by double staining of Tn and alpha-SMA, deposition of Tn a
lso preceded the appearance of the other alpha-SMA-expressing cells in
the mucosa. These observations suggest that Tn could have a role in t
he differentiation of intestinal contractile cells.