Figure 1.
Preliminary Molecular Phylogeny of the Deuterostome Aquaporin Superfamily.
The Bayesian majority rule consensus tree of the codon alignment is rooted with aqpM. The aquaporin subfamilies annotated in the central coil are separated into four major grades: aquaglyceroporins (G), unorthodox aquaporins (U), aquaporin 8-type (8) and classical aquaporins (C). Posterior probabilities are shown at selected nodes. * indicates sequencing of taxon. Evolutionary older nodes associated with Cyclostomata, Chondrichthyes and Actinisia are respectively shaded in yellow, grey and magenta. Teleost and tetrapod subclusters are shaded according to the aquaporin grade, except for sarcopterygian Aqp2, -5, and -6 paralogs, which are shaded in pink.
Figure 2.
Molecular Phylogeny of Deuterostome Classical Aquaporins.
Bayesian majority rule consensus tree of the codon alignment is rooted with cnidarian aqp4L1. Posterior probabilities are shown at each node, with the number of taxa analysed given in square brackets. The scale bar represents the rate of nucleotide substitution per site. Chondrichthyan, actinopteryian and sarcopteygian subclusters are respectively shaded in light grey, cyan and magenta, while evolutionary older nodes associated with Cyclostomata and basal Deuterostomia are respectively shaded in yellow and dark grey. The tetrapod AQP2, -5, -5-like (5L), and -6 paralogs are shaded in pink. See Figure S11 for the fully annotated tree.
Figure 3.
Syntenic arrangement of the vertebrate aquaporin gene clusters.
(A) Synteny is shown in relation to conserved nuclear receptors, and the keratin (KRT), olfactory receptor (OR), vomeronasal receptor (VRE), homeobox C (HOXC) superclusters. Circular arrows indicate that the linkage group is flipped, and coding direction is indicated by the pointed end of the gene symbols. (B) Genomic structure of the Arctic lamprey aqp01 and -14 paralogs.
Table 1.
Classical aquaporin aromatic-arginine constriction residues in Deuterostomia.
Figure 4.
Evolutionary Distribution of Deuterostome Classical Aquaporins.
(A) Phylogenetic relationships of the major deuterostome groups studied. (B) Prevalence of classical aquaporin genes identified in each lineage showing postscript nomenclature for duplicated forms. Coloured dots are specific for the species shown, white dots are found in the same lineage, but a different species, while grey dots indicate pseudogenes.
Table 2.
Presence and absence of gnathostome nuclear receptor subfamilies with syntenic paralogs (•) to aqp0, -14, -2, -5, -5L, -6, or (:) aquaglyceroporins.
Figure 5.
Evolution of the Aquaporin Apormorphy in Sarcopterygii.
Schematic illustration showing aquaporin subfamilies identified in deuterstome phyla in relation to geological time.
Table 3.
Prevalence of aquaporins identified in deuterostome animals.
Figure 6.
Evolutionary model and ancestry of the deuterostome aquaporin superfamily.
Archaea and Bacteria are encapsulated in a putative “ring of life” scenario. Dotted lines indicate uncertain relationships. White nodes indicate tandem duplication, coloured nodes are associated with serial rounds (R1–R3) of whole genome duplication. The nomenclature and model are explained further in the text. The tetrapodomorph shown above node 4 is Tiktaalik roseae, which likely harboured the aqp2-like genes as shown for Actinistia and Dipnoi in Figure 2.