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Figure 1. Protein Structure and Gene Expression of xHtrA1(A) SDS-PAGE of supernatant from transfected and 35S-methionine/cysteine-labeled HEK293T cells. The 50 kDa band corresponds to the secreted xHtrA1 protein.(B) Xenopus HtrA1 and related proteins. SP, signal peptide; IB, insulin-like growth factor binding domain; K, kazal-type serine protease inhibitor domain; Trypsin, trypsin-like serine protease domain; PDZ, PDZ domain. The numbers indicate the percentages of amino acid identity with the corresponding domains in xHtrA1. The GenBank accession numbers are Xenopus laevis HtrA1 (EF490997), human HtrA1/L56 (NP 002766), mouse HtrA1 (AAH13516), Drosophila serine protease (NP 650366), and E. coli HtrA/DegP (X12457).(C–J) Whole-mount in situ hybridization of xHtrA1 (C–F) and FGF8 (G–J) at midgastrula (C and G, vegetal view), early neurula (D and H, dorsal view), midneurula (E and I, anterior view), and tail bud stage (F and J, head). The arrowhead indicates the midbrain-hindbrain boundary. anp, anterior neural plate; ba, branchial arch; bpl, blastopore lip; fb, forebrain; nf, neural folds; pm, posterior mesoderm.(K) RT-PCR of animal cap explants at stage 18 after injection of FGF8 (450 pg), FGF4 (3 pg), or BMP4 mRNA (200 pg) at the 4-cell stage. H4, histone H4 for normalization. |
