Figure 4.

Reciprocal protostome versus deuterostome BLAST searches. Reciprocal BLAST searches were used to identify protostome representatives of missing fly homeodomains and deuterostome representatives of missing human homeodomains. Human homeodomains representing the ANF, BARX, HOX3, IPF/XLOX, MIX, PROX, SATB, and SHOX families were used as queries for BLASTp searches of protostome entries in the non-redundant (NR) protein database. The top hit was then BLASTed back against our dataset. Similarly, the fruit fly dveA homeodomain (COMPASS family) was used as a query to search deuterstome proteins. The top hit was then blasted back against our dataset. The initial query sequence and the top hits in each BLASTp search are aligned to the Drosophila Antennapedia homeodomain. The BLASTp scores and E-values are shown, as are the percentage of amino acid 'identities' (% id) and 'positives' (% pos). Species abbreviations are as follows: Bf, Branchiostoma floridae; C, Capitella species; Ce, Caenorhabditis elegans; Cs, Cupiennius salei; Dm, Drosophila melanogaster; Hs, Homo sapiens; Ht, Helobdella triserialis; Ps, Phascolion strombi; Sp, Strongylocentrotus purpuratus.