Fig. 7
From: Tracing the evolution of the heterotrimeric G protein α subunit in Metazoa
ML tree of the Gαi family resolves gene relationships. a ML tree built with all protein-coding sequences found within the (pre) Gαi family (preGNAI, GNAI1–4, GNAT1–3, (pre) GNAO, and GNAZ) in all Deuterostomia lineages evaluated. All lamprey branches are denoted in pink. The outgroups of the GNAI and GNAT genes have high bootstrap supports (GNAT1–100 and GNAI2–92). The two GNAT lamprey genes form a monophyletic group with GNAT1 and GNAT2 of jawed Vertebrata, as do GNAO and GNAZ lamprey genes with their respective subtrees. b GNAI1 and GNAI3 are situated next to GNAT2 and GNAT3, respectively, within the genome. These pairs are the result of the duplication of the respective GNAI1/3-GNAT3/2 gene pair. GNAI2 and GNAI4 are situated next to GNAT1 and GNAT4, respectively; they arose from GNAI2/4-GNAT1/4 gene pair during the same duplication event. GNAI4 and GNAT4 (red) are not observed in the genomic data investigated (except for GNAI4 in lamprey)