The T. thermophila sortilins fall into two major groups. A maximum likelihood phylogeny of the ciliate VPS10 domains shown in Fig. 2 B, together with the most highly related homologues (as judged by BLAST scores) present in a variety of organisms from the other major eukaryotic lineages. VPS10 domain–containing genes appear to have been entirely lost in numerous organisms including A. thaliana and D. melanogaster. In some fungi, VPS10 domains are present as tandem repeats, depicted as h1 and h2. Species are abbreviated as follows: Aspergillus nidulans (An), Coccomyxa subellipsoidea (Cs), Daphnia pulex (Dap), Dictyostelium discoideum (Dd), Dictyostelium fasciculatum (Df), Dictyostelium purpureum (Dp), Homo sapiens (Hs), Ichthyophthirius multifiliis (Im), M. pusilla (Mp), Micromonas sp. RCC299 (Mr), Mus musculus (Mm), Naegleria gruberi (Ng), Naumovozyma castellii (Nac), Ostreococcus lucimarinus (Ol), Ostreococcus tauri (Ot), Paracoccidioides brasiliensis (Pab), P. tetraurelia (Pt), Polysphondylium pallidum (Pp), Punctularia strigosozonata (Ps), S. cerevisiae (Sc), T. thermophila (Tt), Trichoplax adhaerens (Tra), Xenopus (Silurana) tropicalis (Xt), Yarrowia lipolytica (Yl). See also Table S1 for a list of accession numbers for the sequences used to assemble this phylogeny.