Immunohistochemical Localization and Expression of Aquaporin Water Channel Membrane Transport Protein Homologues in the Osmoregulatory Tissues of the Dogfish (Squalus acanthias)

Very little data is available concerning the presence of homologues of members of the aquaporin water and small solute channel protein family in elasmobranches. Recently Cutler et al. (2005) and Meischke et al. (2007), identified an aquaporin homologue from the euryhaline Bullshark ( Carcharhinus leucas ). This sequence data has since been utilized to identify four further aquaporin homologues from the dogfish (Cutler, 2007; Squalus acanthias ). Affinity purified polyclonal antibodies were then generated against the C-terminal end of each dogfish aquaporin protein. Immunohistochemical localization studies were initiated to determine the cellular localization of these aquaporin isoforms in osmoregulatory tissues of the dogfish, including rectal gland, kidney, gill, oesophagus and intestine/rectum. Results from these studies will be presented as time allows.