Enables water channel activity. Acts upstream of or within cellular response to water deprivation; metanephric collecting duct development; and renal water transport. Located in several cellular components, including apical plasma membrane; perinuclear region of cytoplasm; and recycling endosome. Is expressed in inner ear; metanephros; vestibulo-cochlear ganglion; and vestibulocochlear nerve cochlear component. Used to study nephrogenic diabetes insipidus. Human ortholog(s) of this gene implicated in nephrogenic diabetes insipidus. Orthologous to human AQP2 (aquaporin 2). [provided by Alliance of Genome Resources, Apr 2022]