| |
Fig. 5. BMP-4 mRNA expression in the Xenopus laevis intestine
during metamorphic climax (A) and the stage 57 tadpole
intestines cultured for 5 days in the presence of thyroid hormone
(TH) (B–D). (A) When adult epithelial primordia (AE) grow in size,
signals in the connective tissue (CT) become stronger with a
gradient toward the primordia. (B) Intact intestine. BMP-4
expression is upregulated in the connective tissue just beneath
the epithelium. (C, D) Epithelium-free intestines in the absence
(C) and presence of Shh (500 ng/mL) (D). Shh induces BMP-4
expression only in the connective tissue. M, muscle. Scale bars,
20 μm. |
