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Figure 4. Expression of bone morphogenic protein-4 (BMP-4; A,B), BMPR-IA (C), and Tolloid/BMP-1 (D) mRNA analyzed by in situ hybridization (ISH) with a digoxigenin (DIG) -labeled antisense RNA probe. A,B: BMP-4 mRNA reaches the maximum level around stage 62 in the connective tissue (CT). There is a gradient in its amount toward the adult epithelial primordia (P-AE; B). C,D: The level of BMPR-IA (C) and Tolloid/BMP-1 mRNA (D) is the highest around stage 61. BMPR-IA mRNA is weakly expressed in both the connective tissue and the adult epithelial primordia (arrowheads), but not in the larval epithelium (LE; C). In contrast, Tolloid/BMP-1 mRNA is expressed only in the connective tissue without a gradient (D). M, muscles. Scale bars = 20 mu m. |
