Fig. 5. Nv-mef2. Phylogenetic analysis and gene expression. (A) Alignment of 68 amino acids from the conserved MADS domain of various mef2 genes plus blistered and serum response factor (SRF). (B) Phylogeny of mef2 sequences. The tree was constructed and labeled as in Fig. 3. Phylogenetic analysis was based on the amino acid sequence of the MADS domain. Sequences included in the analysis are: blistered, Drosophila, residues 166-233; mef2 (myocyte enhancing factor 2), Drosophila, residues 2-69; mef2, Nematostella, residues 2-69; mef2, Podocoryne, residues 2-69; MEF2A (myocyte enhancer factor 2A), Homo, residues 2-69; MEF2B, Homo, residues 2-69; MEF2C, Homo, residues 2-69; MEF2D, Homo, residues 2-69; SRF (serum response factor), Homo, residues 142-209. (C-G) Expression of Nv-mef2. (C) Expression begins in individual cells distributed broadly around the circumference of the blastula. (D,E) Throughout the development of the planula, expression remains confined to epidermal cells. (F,G) As development continues, Nv-mef2 expression comes to be preferentially expressed at the oral pole (arrows), particularly along the surface of the developing tentacle buds (tb) and tentacles (tn).