Assessment of S and N probes. (A) Southern blot analysis of subtracted probe pools. (S) Forward subtraction (shh:gfp vs. ngn1:gfp line); (N) reverse subtraction (ngn1:gfp vs. shh:gfp line). Blotted cDNAs are oep (one-eyed pinhead), ntl (no tail), fkd4, (forkhead 4), col2a1 (collagen type II α-1), flh (floating head), pax2b, msxb, elav, dla (δA), dld (δD). (B-G) Expression pattern of clones of the S subtraction. (B) Clone s1h9, zebrafish EST fc02c07.y1, shows expression in the notochord and the tail bud (arrowhead). (C) Clone s2a5, zebrafish EST fm63h08.x1, is expressed in the notochord, but excluded from the tail bud (arrowhead). (D) Clone s2b4 is expressed in the notochord (arrowhead). (E) Clone s2c1, procollagen C-terminal enhancer protein 2, is expressed in the notochord and the edge of the lateral plate mesoderm (white arrowhead). (F) Clone s2c8, apolipoprotein H, shows expression in the notochord and the adaxial edge of the somites (arrow). (G) Clone s2d6, zebrafish EST fm91b12.x1, is expressed in the notochord and both the edge of the lateral plate mesoderm (arrowhead) and the adaxial part of the somites (arrow). (B-D) Lateral view, dorsal right; (E-G) dorsal view, anterior up.
