Fig. 3. Nv-forkhead. Phylogenetic analysis and gene expression. (A) Alignment of 81 amino acids from the conserved forkhead domain (top), 35 amino acids from the transcription activation domain II (bottom left) and 16 amino acids from the transcription activation domain III (bottom right) (Pani et al., 1992). (B) Neighbor-joining tree produced from the 81 amino acids of the forkhead domain. Branch lengths are proportional to the number of substitutions per residue. Numbers at nodes indicate bootstrap support (percentage of 2000 bootstrap replicates in which the given clade was recovered). Some branch lengths were truncated by 50% for presentation purposes (indicated by x2). Sequences included in the analysis are: bin (biniou), Drosophila, residues 312-391; budhead, Hydra vulgaris, residues 82-159; CG32006-PA (hypothetical protein), Drosophila, residues 147-220; fkh (fork head), Drosophila, residues 211-288; FOXA2 (forkhead box A2), Homo, residues 160-237; FOXB1, Homo, residues 14-91; FOXC1, Homo, residues 79-157; FOXD1, Homo, residues 126-203; FOXE1, Homo, residues 54-131; FOXM1, Homo, residues 237-312; slp2 (sloppy paired 2), Drosophila, residues 182-258; fox (fork head box protein), Nematostella, residues 40-117. (C) Surface view of a late blastula showing localized expression at the future site of the blastopore. (D) Lateral view of the same stage. (E) The first cells that enter the blastocoel express Nv-forkhead. (F-J) Only cells of the pharynx (pha) and pharyngeal mesenteries (mes) express this gene. Asterisks indicate the site of the blastopore, the future mouth.