Figure 3.

Phylogenetic trees of TGF-β type I (a) and type II (b) receptors. The trees were constructed using the same method as described in Figure 2. (a) Type I receptors from elephant shark, coelacanth, spotted gar, xenopus, human, zebrafish and tilapia were clustered into ALK1/2, ALK3/6 and ALK4/5/7 three branches, tilapia TGFBR2B was used as an outgroup; (b) Type II receptors from elephant shark, coelacanth, spotted gar, xenopus, lizard, chicken, human, zebrafish and tilapia were clustered into ACVR2A/ACVR2B, TGFBR2 and BMPR2/AMHR2 three branches, human ACVR1 was used as an outgroup. Red dots indicate genes which retained two copies in teleosts after 3R events. GenBank accession numbers of the sequences used are listed in Table S2b,c.