Table 1.
TGF-β pathway gene content across the animal taxa.
| Data source | Smad | Receptor | BAMBI (*) | Chordin Family | Gremlin family | |
| Homo sapiens | E/TF5 | 8 | 13Ω | 1 | 7 | 5 |
| Pan troglodytes | E/TF5 | 8 | 12 | 1 | 7 | 4 |
| Macaca mulatta | E/TF5 | 8 | 13Ω | 1 | 5 | 5 |
| Mus musculus | E/TF5 | 8 | 12 | 1 | 7 | 5 |
| Rattus norvegicus | E/TF5 | 8 | 13Ω | 1 | 6 | 4 |
| Canis domesticus | E/TF5 | 8 | 9 | 1 | 7 | 5 |
| Gallus gallus | E/TF5 | 7 | 11 | 1 | 6 | 3 |
| Danio rerio | E/TF5 | 121 | 18 | 1 | 6 | 6 |
| Oryzias latipes | E/TF5 | 121 | 15 | 1 | 4 | 5 |
| Takifugu rubripes | E/TF5 | 131 | 21 | 1 | 7 | 4 |
| Tetraodon nigroviridis | E/TF5 | 14 1 | 20 | 1 | 9 | 2 |
| Ciona savignyi | E/TF5 | 5‡ | 6 | -- | 2 | 1 |
| Ciona intestinalis | E/TF5 | 5‡‡ | 7 | -- | 3 | 1 |
| Drosophila melanogaster | FB | 4 | 5 | -- | 1 | 1 |
| Apis mellifera | E/TF5 | 4 | 5 | -- | 1 | 1 |
| C. elegans, briggsae and remanei | WB | 6 | 3 | -- | 1 | 1 |
| Capitella sp. I | J | 4 | 5 | 1 | 4 | 1 |
| Helobdella robusta | J | 4‡‡‡ | 5 | -- | -- | 2 |
| Lottia gigantea | J | 4 | 5 | 1 | 4 | 1 |
| Trichoplax adhaerens | J | 4 | 4 | -- | 1 | 1 |
| Protozoans (Monosiga brevicollis, Volvox carteri, Naegleria gruberi) | J | -- | -- | -- | -- | -- |
1 For details, see Figure 3
(*) Inhibitory co-receptor BAMBI, although probably present in Urbilateria, appears to be frequently lost, such as in Ecdysozoa, tunicates, and Helobdella
‡ Species-specific TGF-β-R-Smad duplication (see also Figure S1)
‡‡ Species-specific Co-Smad duplication (see also Figure S1)
‡‡‡ Leech Helobdella has a modified pathway: with an additional Co-Smad (Figure S3, [see Additional file 3]) and a distinct set of ligand traps
Ω Including a retrogene of BMPR1A of unverified functionality: ENSG00000185932 (H. sapiens, 337 aa, intracellular domains only), ENSMMUG00000031530 (M. mulatta, 211 aa, some intracellular domains), ENSRNOG00000011012 (R. norvegicus, 529 aa, all domains)
The table indicates the numbers of genes in each family.
Data sources: Ensembl 46 (E), TreeFam 5 (TF5), JGI (J), WormBase (WB), FlyBase (FB)