{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,25]],"date-time":"2026-04-25T17:34:27Z","timestamp":1777138467377,"version":"3.51.4"},"reference-count":47,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,1,28]],"date-time":"2026-01-28T00:00:00Z","timestamp":1769558400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100012307","name":"MDIBL","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100012307","id-type":"DOI","asserted-by":"crossref"}]},{"name":"author"},{"name":"host institution"},{"DOI":"10.13039\/100006376","name":"Georgia Southern University","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100006376","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>The aquaporin 0 (AQP0)\/major intrinsic protein of eye lens (MIP) cDNA was cloned and sequenced. Initial studies of the tissue distribution of mRNA expression proved to be incorrect. Subsequent experiments showed that AQP0 mRNA is expressed strongly in the eye with moderately strong expression in the kidneys and some expression was seen in the brain and muscle tissue, and very low expression in the esophagus\/fundic stomach. Another set of PCR reactions with five times the amount of cDNA additionally showed mRNA\/cDNA expression in the liver, rectal gland, and a very low level in the intestine. Sporadic expression of different pieces of AQP0 cDNA was seen in various experiments in gill and pyloric stomach. A custom polyclonal antibody was produced against a region near the C-terminal end of the AQP0 protein sequence. The antibody gave a band of around the correct size (for the AQP0 protein) on the Western blot, which also showed a few other higher-molecular-weight bands. The antibody was also used in immunohistochemistry, and in the kidney, it showed staining in the proximal II (PII), intermediate segment I (IS I), and late distal tubule (LDT) parts of the sinus zone region of nephrons as well as some staining in the bundle zone tubule segments, suggesting a role for AQP0 as a water channel. In the rectal gland, the antibody showed weak apical membrane staining in a few secretory tubules near the duct, but also somewhat stronger staining in cells appearing to connect various secretory tubules, suggesting a role in cell\u2013cell adhesion. In the spiral valve intestine side wall and valve flap, after signal amplification, weak antibody staining was seen in the apical and lateral membranes of epithelial cells adjacent to the luminal surface. There was also some staining in the intestinal muscle. In the rectum\/colon, staining was seen in a layer of cells underlying the epithelium and in some muscle layers. In the gill, there was very weak staining in secondary lamellae epithelial cells and in connective tissue surrounding blood vessels and blood sinuses. The low level of transcript expression in the rectal gland, gill, and intestinal tissues suggests caution in the interpretation of the immunohistochemical staining in these tissues.<\/jats:p>","DOI":"10.3390\/ijms27031317","type":"journal-article","created":{"date-parts":[[2026,1,28]],"date-time":"2026-01-28T15:04:46Z","timestamp":1769612686000},"page":"1317","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Localization and Expression of Aquaporin 0 (AQP0\/MIP) in the Tissues of the Spiny Dogfish (Squalus acanthias)"],"prefix":"10.3390","volume":"27","author":[{"given":"Christopher P.","family":"Cutler","sequence":"first","affiliation":[{"name":"Department of Biology, Georgia Southern University, Statesboro, GA 30460, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Casi R.","family":"Curry","sequence":"additional","affiliation":[{"name":"Department of Biology, Georgia Southern University, Statesboro, GA 30460, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fallon S.","family":"Hall","sequence":"additional","affiliation":[{"name":"Department of Biology, Georgia Southern University, Statesboro, GA 30460, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-1761-7165","authenticated-orcid":false,"given":"Tolulope","family":"Ojo","sequence":"additional","affiliation":[{"name":"Department of Biology, Baylor University, Waco, TX 76706, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1016\/0092-8674(84)90190-9","article-title":"The major intrinsic protein (MIP) of the bovine lens fiber membrane: Characterization and structure based on cDNA cloning","volume":"39","author":"Gorin","year":"1984","journal-title":"Cell"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"11110","DOI":"10.1073\/pnas.88.24.11110","article-title":"Isolation of the cDNA for erythrocyte integral membrane protein of 28 kilodaltons: Member of an ancient channel family","volume":"88","author":"Preston","year":"1991","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1007\/s10157-008-0118-6","article-title":"Aquaporin water channels in Mammals","volume":"13","author":"Ishibashi","year":"2009","journal-title":"Clin. Exp. Nephrol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Finn, R.N., Chauvign\u00e9, F., Hlidberg, J.B., Cutler, C.P., and Cerd\u00e0, J. (2014). The lineage-specific evolution of aquaporin gene clusters facilitated tetrapod terrestrial adaptation. PLoS ONE, 9.","DOI":"10.1371\/journal.pone.0113686"},{"key":"ref_5","first-page":"7","article-title":"Expression and localization of aquaporin water channels in rat hepatocytes","volume":"4","author":"Grant","year":"2002","journal-title":"Kidney"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"22710","DOI":"10.1074\/jbc.M202394200","article-title":"Expression and localization of aquaporin water channels in rat hepatocytes. Evidence for a role in canalicular bile secretion","volume":"277","author":"Huebert","year":"2002","journal-title":"J. Biol. Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1115","DOI":"10.1002\/ar.22709","article-title":"Region-specific expression of aquaporin subtypes in equine testis, epididymis and ductus deferens","volume":"296","author":"Klein","year":"2013","journal-title":"Anat. Rec."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Schey, K.L., Petrova, R.S., Gletten, R.B., and Donaldson, P.J. (2017). The Role of Aquaporins in Ocular Lens Homeostasis. Int. J. Mol. Sci., 18.","DOI":"10.3390\/ijms18122693"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1007\/s002329900266","article-title":"Comparison of the water transporting properties of MIP and AQP1","volume":"159","author":"Chandy","year":"1997","journal-title":"J. Membr. Biol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1393","DOI":"10.1167\/iovs.04-1217","article-title":"Regulation of aquaporin water permeability in the lens","volume":"46","author":"Varadaraj","year":"2005","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_11","first-page":"175","article-title":"Characterization of Human Lens Major Intrinsic Protein Structure","volume":"41","author":"Schey","year":"2000","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1016\/j.sbi.2007.11.003","article-title":"Junction-forming aquaporins","volume":"18","author":"Engel","year":"2008","journal-title":"Curr. Opin. Struct. Biol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Roche, J.V., and T\u00f6rnroth-Horsefield, S. (2017). Aquaporin protein-protein interactions. Int. J. Mol. Sci., 18.","DOI":"10.3390\/ijms18112255"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1016\/S0014-4835(05)80124-1","article-title":"Biochemical evidence for adhesion-promoting role of major intrinsic protein isolated from both normal and cataractous human lenses","volume":"61","author":"Michea","year":"1995","journal-title":"Exp. Eye Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2255","DOI":"10.1083\/jcb.108.6.2255","article-title":"The structural organization and protein composition of lens fiber junctions","volume":"108","author":"Zampighi","year":"1989","journal-title":"J. Cell Biol."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Li, Z., Quan, Y., Gu, S., and Jiang, J.X. (2022). Beyond the Channels: Adhesion Functions of Aquaporin 0 and Connexin 50 in Lens Development. Front. Cell Dev. Biol., 10.","DOI":"10.3389\/fcell.2022.866980"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"9856","DOI":"10.1021\/bi0496034","article-title":"Post-translational Modifications of Aquaporin 0 (AQP0) in the Normal Human Lens: Spatial and Temporal Occurrence","volume":"43","author":"Ball","year":"2004","journal-title":"Biochemistry"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1038\/nature04321","article-title":"Lipid-protein interactions in double-layered two-dimensional AQP0 crystals","volume":"438","author":"Gonen","year":"2005","journal-title":"Nature"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1007\/s12551-021-00925-3","article-title":"Aquaporin ion conductance properties defined by membrane environment, protein structure, and cell physiology","volume":"14","author":"Henderson","year":"2022","journal-title":"Biophys. Rev."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1042\/BCJ20230158","article-title":"The role of phosphorylation in calmodulin-mediated gating of human AQP0","volume":"481","author":"Kreida","year":"2024","journal-title":"Biochem. J."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Ozu, M., Galizia, L., Acu\u00f1a, C., and Amodeo, G. (2018). Aquaporins: More than functional monomers in a tetrameric arrangement. Cells, 7.","DOI":"10.3390\/cells7110209"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"981","DOI":"10.1016\/0888-7543(91)90023-8","article-title":"Genomic cloning, complete nucleotide sequence, and structure of the human gene encoding the major intrinsic protein (MIP) of the lens","volume":"11","author":"Pisano","year":"1991","journal-title":"Genomics"},{"key":"ref_23","unstructured":"Peracchia, C. (1994). Chapter 27\u2014The MIP transmembrane channel family. Handbook of Membrane Channels, Academic Press."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1007\/s002329900549","article-title":"The role of MIP in lens fiber cell membrane transport","volume":"170","author":"Varadaraj","year":"1999","journal-title":"J. Membr. Biol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1002\/jez.a.10307","article-title":"The ocular lens fiber membrane specific protein MIP\/Aquaporin 0","volume":"300A","author":"Chepelinsky","year":"2003","journal-title":"J. Exp. Zool."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1016\/j.mam.2012.02.001","article-title":"Structure, function and translational relevance of aquaporin dual water and ion channels","volume":"33","author":"Yool","year":"2012","journal-title":"Mol. Aspects Med."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1513","DOI":"10.1016\/j.bbagen.2013.10.037","article-title":"Aquaporins in the eye: Expression, function, and roles in ocular disease","volume":"1840","author":"Schey","year":"2014","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"4021","DOI":"10.1167\/iovs.18-26270","article-title":"Connexin 50 and AQP0 are Essential in Maintaining Organization and Integrity of Lens Fibers","volume":"60","author":"Gu","year":"2019","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Tinguad-Sequeira, A., Calusinka, M., Finn, R.N., Chauvign\u00e9, F., Lozano, J., and Cerd\u00e0, J. (2010). The zebrafish genome encodes the largest vertebrate repertoire of functional aquaporins with dual paralogy and substrate specificities similar to mammals. BMC Evol. Biol., 10.","DOI":"10.1186\/1471-2148-10-38"},{"key":"ref_30","first-page":"37","article-title":"Subcellular Localization of Selectively Permeable Aquaporins in the Male Germ Line of a Marine Teleost Reveals Spatial Redistribution in Activated Spermatozoa","volume":"89","author":"Boj","year":"2013","journal-title":"Biol. Reprod."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2172","DOI":"10.1096\/fj.14-267625","article-title":"The pH sensitivity of Aqp0 channels in tetraploid and diploid teleosts","volume":"29","author":"Zapater","year":"2015","journal-title":"FASAB J."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Chauvign\u00e9, F., Fjelldal, P.G., Cerd\u00e0, J., and Finn, R.N. (2016). Auto-Adhesion Potential of Extraocular Aqp0 during Teleost Development. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0154592"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2856","DOI":"10.1242\/jeb.025882","article-title":"Expression and functional characterization of four aquaporin water channels from the European Eel (Anguilla anguilla)","volume":"212","author":"MacIver","year":"2009","journal-title":"J. Exp. Biol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1086\/BBLv229n1p70","article-title":"Water Transport and Functional Dynamics of Aquaporins in Osmoregulatory Organs of Fishes","volume":"229","author":"Madsen","year":"2015","journal-title":"Biol. Bull."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Yang, B. (2017). Chapter 10, The physiological role and regulation of aquaporins in teleost germ cells. Aquaporins, Springer-Nature. Advances in Experimental Medicine and Biology.","DOI":"10.1007\/978-94-024-1057-0"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"119330","DOI":"10.1016\/j.gep.2023.119330","article-title":"The role of mip in the development of lens in zebrafish","volume":"49","author":"He","year":"2023","journal-title":"Gene Expr. Patterns"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"7577","DOI":"10.1021\/acs.jpcb.4c03015","article-title":"Molecular dynamics simulations of the eye lens water channel aquaporin 0 from fish","volume":"128","author":"Freites","year":"2024","journal-title":"J. Phys. Chem. B"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Yilmaz, O., Chauvign\u00e9, F., Ferr\u00e9, A., Nilsen, F., Fjelldal, P.G., Cerd\u00e0, J., and Finn, R.N. (2020). Unravelling the complex duplication history of deuterostome glycerol transporters. Cells, 9.","DOI":"10.3390\/cells9071663"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"110730","DOI":"10.1016\/j.cbpb.2022.110730","article-title":"Short Communication: The Aquaporin 8 (AQP8) membrane channel gene is present in the Elasmobranch dogfish (Squalus acanthias) genome and is expressed in brain but not in gill, kidney or intestine","volume":"26","author":"Cutler","year":"2022","journal-title":"Comp. Biochem. Physiol."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Cutler, C.P., MacIver, B., Cramb, G., and Zeidel, M.L. (2012). Aquaporin 4 is a ubiquitously expressed isoform in the dogfish (Squalus acanthias) shark. Front. Physiol., 2.","DOI":"10.3389\/fphys.2011.00107"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"110701","DOI":"10.1016\/j.cbpb.2021.110701","article-title":"Aquaporin (AQP) channels in the spiny dogfish, Squalus acanthias II: Localization of AQP3, AQP4 and AQP15 in the kidney","volume":"258","author":"Cutler","year":"2022","journal-title":"Comp. Biochem. Physiol. B"},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Cutler, C.P., and MacIver, B. (2025). Localization and expression of aquaporin 1 (AQP1) in the tissue of the spiny dogfish (Squalus acanthias). Int. J. Mol. Sci., 26.","DOI":"10.3390\/ijms26125593"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"378","DOI":"10.3390\/hydrobiology3040024","article-title":"Immunohistochemical localization and expression of aquaporin 3-2 (AQP3C1) in the spiny dogfish, Squalus acanthias","volume":"3","author":"Cutler","year":"2024","journal-title":"Hydrobiology"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"110702","DOI":"10.1016\/j.cbpb.2021.110702","article-title":"Aquaporin (AQP) channels in the spiny dogfish, Squalus acanthias I: Characterization of AQP3 and AQP15 function and expression, and localization of the proteins in gill and spiral valve intestine","volume":"258","author":"Cutler","year":"2022","journal-title":"Comp. Biochem. Physiol. B"},{"key":"ref_45","first-page":"R398","article-title":"Diluting segment in kidney of dogfish shark I. Localization and characterization of chloride absorption","volume":"258","author":"Friedman","year":"1990","journal-title":"Am. J. Physiol."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Cutler, C.P., Omoregie, E., and Ojo, T. (2024). UT-1 transporter expression in the spiny dogfish (Squalus acanthias): UT-1 protein shows a different localization in comparison to that of other sharks. Biomolecules, 14.","DOI":"10.3390\/biom14091151"},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Cutler, C.P., Harmon, S., and Walsh Burch, K. (2012). Characterization of aquaporin 4 protein expression and localization in tissues of the dogfish (Squalus acanthias). Front. Physiol., 3.","DOI":"10.3389\/fphys.2012.00021"}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/3\/1317\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T05:18:44Z","timestamp":1769750324000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/3\/1317"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,28]]},"references-count":47,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2026,2]]}},"alternative-id":["ijms27031317"],"URL":"https:\/\/doi.org\/10.3390\/ijms27031317","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,28]]}}}