Metazoan and plant AQP12-like orthologs are targeted to the YPM when expressed in X. laevis oocytes. (A) Bayesian majority rule consensus tree of the unorthodox AQP12-related channel CDS of Viridiplantae and Metazoa. The tree is inferred from 10 million MCMC generations and midpoint rooted with posterior probabilities shown at each node. The number of taxa in each triangle is indicated in square parentheses. (B) Representative immunostaining of HA-tagged AQP12-related orthologs (green) in YPs isolated from X. laevis oocytes expressing human (HsAQP12A-HA), zebrafish (DrAqp12-HA), nematode (CeAqp12-HA), jellyfish (NvAqp12-HA), thale cress (AtSIP1A-HA), and untagged Aqp12L2 from the salmon louse (LsAqp12L2), using an α-HA antibody or an α-LsAqp12L2–specific antibody. The YPM (arrowheads) is counterstained with WGA (red), whereas the intra-YP yolk proteins are labeled with an α-Lv antibody (blue). The lower two panels show YPs extracted from uninjected oocytes (controls) probed with the α-HA or α- LsAqp12L2 antibodies. BF, bright field. Scale bars, 5 µm. (C) Immunoblot of protein extracts from TM and YPM of uninjected oocytes or oocytes expressing the different AQP12-related orthologs using the antibodies specified above. The α-PDI antibody was used as a protein loading control. The arrows indicate the aquaporin monomers. Molecular mass markers (kDa) are on the left. TM, total membrane. Source data are available for this figure: SourceData F1.