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Evidence That Aquaporin 11 (Aqp11) In The Spiny Dogfish (Squalus Acanthias) May Represent A Pseudogene, Christopher P. Cutler, Meghan Canicatti, Esosa Omoregie

Biology: Faculty Publications

Various attempts to amplify an AQP11 cDNA from tissues of the spiny dogfish (Squalus acanthias) were made. Two pairs of deoxy-inosine-containing degenerate primers were designed based on conserved amino acid sequences from an AQP11 alignment. These primers yielded some faint bands from gill cDNA that were sequenced. Blast searches with the sequences showed they were not AQP11. An elasmobranch AQP11 nucleotide sequence alignment was produced to identify conserved regions to make further degenerate primers. One primer pair produced a short 148 bp fragment showing particularly strong amplification in gill and intestine. It was sequenced and represented a piece of the …

Aquaporin Expression And Cholesterol Content In Eel Swimbladder Tissue, Victoria Drechsel, Gabriel Schneebauer, Birgit Fiechtner, Christopher P. Cutler, Bernd Pelster

Biology: Faculty Publications

Leakiness of the swimbladder wall of teleost fishes must be prevented to avoid diffusional loss of gases out of the swimbladder. Guanine incrustation as well as high concentrations of cholesterol in swimbladder membranes in midwater and deep-sea fish has been connected to a reduced gas permeability of the swimbladder wall. On the contrary, the swimbladder is filled by diffusion of gases, mainly oxygen and CO2, from the blood and the gas gland cells into the swimbladder lumen. In swimbladder tissue of the zebrafish and the Japanese eel, aquaporin mRNA has been detected, and the aquaporin protein has been considered important …

Annotation Of The Nuclear Receptors In An Estuarine Fish Species, Fundulus Heteroclitus, William S. Baldwin

Publications

The nuclear receptors (NRs) are ligand-dependent transcription factors that respond to various internal as well as external cues such as nutrients, pheromones, and steroid hormones that play crucial roles in regulation and maintenance of homeostasis and orchestrating the physiological and stress responses of an organism. We annotated the Fundulus heteroclitus (mummichog; Atlantic killifish) nuclear receptors. Mummichog are a non-migratory, estuarine fish with a limited home range often used in environmental research as a field model for studying ecological and evolutionary responses to variable environmental conditions such as salinity, oxygen, temperature, pH, and toxic compounds because of their hardiness. F. heteroclitus …

World-Class Research: Biomedical Science Beyond Experimentation

Colby Magazine

Faculty and relationships with Maine’s big-three research labs propel Colby’s opportunities in biomedical science

Could childhood nutrition set late-life brain function?

Hitting the lab running

Ahmad wins grant for study of neurodegenerative disease

The Lineage-Specific Evolution Of Aquaporin Gene Clusters Facilitated Tetrapod Terrestrial Adaptation, Roderick Nigel Finn, François Chauvigné, Jón Baldur Hlidberg, Christopher P. Cutler, Joan Cerdà

Biology: Faculty Publications

A major physiological barrier for aquatic organisms adapting to terrestrial life is dessication in the aerial environment. This barrier was nevertheless overcome by the Devonian ancestors of extant Tetrapoda, but the origin of specific molecular mechanisms that solved this water problem remains largely unknown. Here we show that an ancient aquaporin gene cluster evolved specifically in the sarcopterygian lineage, and subsequently diverged into paralogous forms of AQP2, -5, or -6 to mediate water conservation in extant Tetrapoda. To determine the origin of these apomorphic genomic traits, we combined aquaporin sequencing from jawless and jawed vertebrates with broad taxon assembly of …

Characterization Of Aquaporin 4 Protein Expression And Localization In Tissues Of The Dogfish (Squalus Acanthias), Christopher P. Cutler, Sheena Harmon, Jonathan Walsh, Kia Burch

Biology: Faculty Publications

The role of aquaporin water channels such as aquaporin 4 (Aqp4) in elasmobranchs such as the dogfish Squalus acanthias is completely unknown. This investigation set out to determine the expression and cellular and sub-cellular localization of Aqp4 protein in dogfish tissues. Two polyclonal antibodies were generated (AQP4/1 and AQP4/2) and these showed somewhat different characteristics in Western blotting and immunohistochemistry. Western blots using the AQP4/1 antibody showed two bands (35.5 and 49.5 kDa) in most tissues in a similar fashion to mammals. Liver had an additional band of 57 kDa and rectal gland two further faint bands of 37.5 and …

Aquaporin 4 Is A Ubiquitously Expressed Isoform In The Dogfish (Squalus Acanthias) Shark, Christopher P. Cutler, Bryce Maciver, Gordon Cramb, Mark L. Zeidel

Biology: Faculty Publications

The dogfish ortholog of aquaporin 4 (AQP4) was amplified from cDNA using degenerate PCR followed by cloning and sequencing. The complete coding region was then obtained using 5′ and 3′ RACE techniques. Alignment of the sequence with AQP4 amino acid sequences from other species showed that dogfish AQP4 has high levels (up to 65.3%) of homology with higher vertebrate sequences but lower levels of homology to Agnathan (38.2%) or teleost (57.5%) fish sequences. Northern blotting indicated that the dogfish mRNA was approximately 3.2 kb and was highly expressed in the rectal gland (a shark fluid secretory organ). Semi-quantitative PCR further …

Cloning And Sequencing Of Sodium-Hydrogen Exchanger In The Gills Of The Long-Horned Sculpin (Myoxocephalus Octodecimspinosus), Danielle Lee Gunning

College of Graduate Studies: Theses & Dissertations (1964–2006)

No abstract provided.

Acid-Base Regulation In Three Marine Teleosts: The Oyster Toadfish (Opsanus Tau), The Winter Flounder (Pseudopleuronectes Americanus), And The Long-Horned Sculpin (Myoxocephalus Octodecimspinosus), Dana Compton Mccullough

College of Graduate Studies: Theses & Dissertations (1964–2006)

In this study, three species of marine fish were exposed to a variety of dilute salinities in order to determine what effects exposure to diluted seawater may have on acid-base and ion balance. The oyster toadfish (Opsanus tau) and the winter flounder (Pseudopleuronectes americanus) are considered to be able to live in a broad range of salinities, euryhaline (Evans, 1979). The long-homed sculpin, Myoxocephalus octodecimspinosus, is considered to be a stenohaline fish, not able to withstand drastic changes in ambient salinity (Claibome and Evans, 1988).

Initially, toadfish exposed to 20 mM diluted seawater took up …