Dirk Weihrauch
Photo of Dirk Weihrauch

Associate Professor

Office W467 Duff Roblin
204-474-6310

Focus of our current research is the investigation of mechanisms involved in nitrogen excretion and acid-base regulation in invertebrate systems that includes crustaceans, insects, cephalopods, chelicerate, planarians and annelids. In a comparative approach we are also examining the effects of challenges that come due to anthropogenic caused increases in atmospheric PCO2 levels on the physiology of aquatic animals inhabiting fresh and seawater. In addition, using rodent systems and human carcinoma cell lines (T84 and Caco-2) the nitrogen transport mechanism are investigated in the mammalian intestine. For all our study an integrative approach is applied.

Research Interests

Nitrogen transport in the mammalian intestine, Physiology, Integrative and comparative physiology of transepithelial transport, Ammonia transport in changing environmental salinities, Physiological and molecular approaches

Selected Publications

Peer reviewed books:

Book title: Acid-Base Balance and Nitrogen Excretion in Invertebrates - Mechanisms and Strategies in various Invertebrate Groups with Considerations of Challenges caused by Ocean Acidification. Editors: Weihrauch D. and O’Donnell M.J.. Publisher: Springer International Publishing AG (in print), ISBN: 978-3-319-39615-6

Peer reviewed book chapters:

Weihrauch, D., Fehsenfeld, S. Quijada-Rodriguez, A. (2016). Nitrogen excretion in aquatic crustaceans.In: Acid-Base Balance and Nitrogen Excretion in Invertebrates - Mechanisms and Strategies in various Invertebrate Groups with Considerations of Challenges caused by Ocean Acidification. Eds. Weihrauch D. and O’Donnell M.J.. Springer International Publishing AG, pages 1-24.

Quijada-Rodriguez, A., Adlimoghaddam, A., and Weihrauch, D. (2016). Nitrogen excretion in nematodes, flatworms and annelids. In: Acid-Base Balance and Nitrogen Excretion in Invertebrates - Mechanisms and Strategies in various Invertebrate Groups with Considerations of Challenges caused by Ocean Acidification. Eds. Weihrauch D. and O’Donnell M.J.. Springer International Publishing AG, pages 127-150.

Fehsenfeld, S. and Weihrauch, D. (2016). Acid-base regulation in aquatic decapod crustaceans. In: Acid-Base Balance and Nitrogen Excretion in Invertebrates - Mechanisms and Strategies in various Invertebrate Groups with Considerations of Challenges caused by Ocean Acidification. Eds. Weihrauch D. and O’Donnell M.J.. Springer International Publishing AG, pages 151-192.

Peer reviewed articles

In Revision

Weihrauch, D. and Allen G.P.J. (2017). Ammonia excretion in aquatic invertebrates: new insights & new questions. In revision at Journal of Experimental Biology. MS ID#: JEXBIO/2016/154104

Hans, S., Quijada-Rodriguez, A. R., Onken H., Treberg, J., and Weihrauch, D. (2016). Ammonia excretion and acid-base regulation in the living fossil Limulus polyphemus, the American horseshoe crab. To JEB MS ID#: JEXBIO/2016/151894.

Published:

2017

Quijada-Rodriguez, A. R. , Schultz, A. G., Wilson, J. M. He, Y., Allen, G. J. P., Goss, G. G., and Weihrauch, D. (2017). Ammonia independent sodium uptake mediated by Na+ channels and NHEs in the freshwater ribbon leech Nephelopsis obscura. Accepted, Journal of Experimental Biology. JEXBIO/2017/159459.

Adlimoghaddam, A., O’Donnell, M.J., Quijada-Rodriguez, A. R., and Weihrauch, D. (2017). Sodium-hydrogen exchangers in C. elegans and their potential role in hypodermal H+ excretion, Na+ uptake, ammonia excretion and acid-base balance. Canadian Journal of Zoology. 95, 623-632.

Hu, M., Sung, P.-H., Guh, Y.J., Lee, J.-R., Hwang, P.-P., Weihrauch, D., Tseng, Y.-C. (2017). Perfused gills reveal fundamental principles of pH regulation and ammonia homeostasis in the cephalopod Octopus vulgaris. Frontiers in Physiology, 8, 162; doi: 10.3389/fphys.2017.00162

2016

Purschke, G., Hugenschütt, M., Ohlmeier, L., Meyer, H., Weihrauch, D. (2016). Structural analysis of the branchiae and dorsal cirri in Eurythoe complanata (Annelida, Amphinomida) Zoomorphology: first description of segmentally arranged photoreceptive elements in the parapodia of a polychaete. Zoomorphology, accepted 21. November 2016.

Thiel, D., Hugenschütt, M., Meyer, H., Paululat, A., Quijada-Rodriguez, A., Purschke, G., and Weihrauch, D. (2016). Ammonia excretion in the marine polychaete Eurythoe complanata (Annelida). Journal of Experimental Biology, accepted 11. Nov. 2016

Abouelsaad, I., Weihrauch, D. and Renault, S. (2016). Effects of salt stress on the expression of key genes related to nitrogen assimilation and transport in the roots of the cultivated tomato and its wild salt-tolerant relative. Scientia Horticulturae 211 (2016), 70–78

Adlimoghaddam, A. O’Donnell, M.J., Banh, S., Treberg, J.R., Kormish, J., Merz, D. and Dirk Weihrauch (2016). Ammonia excretion in Caenorhabditis elegans: Physiological and molecular characterization of the rhr-2 knock-out mutant. Comp Biochem Physiol A Mol Integr Physiol. 2016 Feb 9;195:46-54. doi: 10.1016/j.cbpa.2016.02.003. [Epub ahead of print]

Chasiotis, H., Ionescu, A., Bui, P., Misyura, L., Fazio, K., Wang, J., Patrick, M., Weihrauch, D. and Donini, A. (2016). An animal homolog of plant Amt/Mep transporters promotes ammonia excretion by the anal papillae of the disease vector mosquito, Aedes aegypti. J Exp Biol. 2016 Mar 4. pii: jeb.134494. [Epub ahead of print].

Fehsenfeld, S. and Weihrauch, D. (2016). The role of an ancestral hyperpolarization activated cyclic nucleotide-gated K+-channel in branchial acid-base regulation in the green crab, Carcinus maenas (L.). Submitted to Journal of Experimental Biology, J Exp Biol. 2016 Jan 19. pii: jeb.134502. [Epub ahead of print]

2015

Fehsenfeld S. and Weihrauch D. (2015). THE MECHANISM OF ACID-BASE REGULATION IN SEAWATER-ACCLIMATED GREEN CRABS, CARCINUS MAENAS. Submitted to Canadian Journal of Zoology (cjz-2015-0132).

Weihrauch D. and O’Donnell M.J. (2015). Links between osmoregulation and nitrogen-excretion in insects and crustaceans. Integr Comp Biol. 2015 Apr 17. pii: icv013. [Epub ahead of print].

Atta K. Agyekum, Jason S. Sands, Alemu Regassa, Elijah Kiarie, Dirk Weihrauch, Wu K. Kim, and Charles M. Nyachoti (2015). Effect of supplementing a high-fiber diet with a xylanase and β-glucanase blend on growth performance and intestinal glucose uptake and transport-associated gene expression in growing pigs. J. Anim. Sci. 2015.93: 3483–3493.

Quijada-Rodriguez A.R., Treberg J.R., and Weihrauch D. (2015). Mechanism of ammonia excretion in the freshwater leech Nephelopsis obscura: characterization of a primitive Rh protein and effects of high environmental ammonia. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 309: R692-R705. (published Sep 2015).

Adlimoghaddam A. Boeckstaens M., Marini A.-M., Treberg, Brassinga A.-K., and Weihrauch D. (2015). Ammonia excretion in Caenorhabditis elegans: mechanism and evidence of ammonia transport of the Rhesus protein CeRhr-1. J Exp Biol. 2015 Mar;218(Pt 5):675-83. doi: 10.1242/jeb.111856.

Highlighted in: JEB.: By Kathryn Knight. Ammonia excretion: C. elegans style. (2015) 218, 647-649.

2014

Adlimoghaddam, A., Weihrauch D., and O’Donnell M.J. (2014). Localization of K+, H+, Na+ and Ca2+ fluxes to the excretory pore in Caenorhabditis elegans: application of scanning ion-selective microelectrodes. J Exp Biol. 2014 Dec 1;217(Pt 23):4119-22.

Erik Hviid Larsen, Lewis E. Deaton, Horst Onken, Michael O’Donnell, Martin Grosell, William H. Dantzler, and Dirk Weihrauch (2014). Osmoregulation and Excretion. 2014 American Physiological Society, Compr Physiol 4:405-573, 2014.

Treberg JR, Banh S, Pandey U, Weihrauch D. (2014). Intertissue Differences for the Role of Glutamate Dehydrogenase in Metabolism. Neurochem Res. 2014 Feb 15. [Epub ahead of print].

2013

Hans, S., Fehsenfeld, S., Treberg, J., and Weihrauch, D. (2013). Acid-base regulation in the Dungeness crab (Metacarcinus magister). Marine Biology 161:1179–1193.

Timsina, BA, Sorensen JL, Weihrauch D, and Piercey-Normore MD. (2013). Effect of aposymbiotic conditions on colony growth and secondary metabolite production in the lichen-forming fungus Ramalina dilacerate. Fungal Biol., 117: 731-43.

Cruz MJ, Sourial MM, Treberg JR, Fehsenfeld S, Adlimoghaddam A, Weihrauch D. (2013). Cutaneous nitrogen excretion in the African clawed frog Xenopus laevis: effects of high environmental ammonia (HEA). Aquat. Toxicol. 136-137:1-12.

Fehsenfeld S, Weihrauch D. (2013) Differential acid-base regulation in various gills of the green crab Carcinus maenas: Effects of elevated environmental pCO2. Comp Biochem Physiol A Mol Integr Physiol. 164:54-65.

Henry RP, Lucu C, Onken H, Weihrauch D. (2013) Multiple functions of the crustacean gill: osmotic/ionic regulation, acid-base balance, ammonia excretion, and bioaccumulation of toxic metals. Front Physiol. Nov 15;3:431, 1-33.

2012

Weihrauch, D., Chan, A.C., Meyer, H., Döring, C. Sourial, M.M. and O’Donnell. M.J. (2012). Ammonia excretion in the freshwater planarian Schmidtea mediterranea. Journal of Experimental Biology 215, 3242-53.

Rodela, T.M. Esbaugh, A.J., Weihrauch, D., Veauvy, C.M., McDonald, M.D., Gilmour, K.M., and Walsh. P.J. (2012). Revisiting the effects of crowding and feeding in the gulf toadfish, Opsanus beta: the role of Rhesus glycoproteins in nitrogen metabolism and excretion. Journal of Experimental Biology, 215, 301-313.

Weihrauch, D., Donini, A., and O'Donnell M.J. (2012). Ammonia transport by terrestrial and aquatic insects. Journal of Insect Physiology, 58(4), 473-87. Highlighted in: Annual Review of Entomology (2015. 60:473–92) by Donald E. Mullins.

Woyengo, T.A., Weihrauch, D., and Nyachoti. C.M. (2012). Effect of dietary phytic acid on performance and nutrients uptake in small intestine of piglets. Journal of Animal Science, 90(2), 543-9.

2011

Martin, M., Fehsenfeld, S., Sourial, M.M. and Weihrauch, D. (2011) Effects of high environmental ammonia on branchial ammonia excretion rates and tissue Rh-protein mRNA expression levels in seawater acclimated Dungeness crab Metacarcinus magister. Comparative Biochemistry and Physiology A Mol. Integr. Physiol. 160, 267-277.

Anderson W.G., Nawata C.M., Wood C.M., Piercey-Normore M.D., and Weihrauch D. (2011). Body fluid osmolytes and urea and ammonia flux in the colon of two chondrichthyan fishes, the ratfish, Hydrolagus colliei, and spiny dogfish, Squalus acanthias. Comparative Biochemistry and Physiology A Mol. Integr. Physiol. 161, 27-35.

Allen. P.J.,Weihrauch, D., Grandmaison, V., Dasiewicz. P., Peake, S.J., and Anderson, W.G. (2011). The influence of environmental calcium concentrations on calcium flux, compensatory drinking and epithelial calcium channel expression in a freshwater cartilaginous fish. Journal of Experimental Biology 214, 996-1006.

2010

Blaesse, A.-K., Broehan, G., Meyer, H., Merzendorfer, H. and Weihrauch, D. (2010). Ammonia uptake in Manduca sexta midgut is mediated by an amiloride sensitive cation/proton exchanger: Transport studies and mRNA expression analysis of NHE7,9, NHE8, and V-ATPase (subunit D). Comparative Biochemistry and Physiology A Mol. Integr. Physiol., 157, 364-367

Anderson, W.G., Dasiewicz, P., Liban, S., Ryan, C., Taylor, J.R., Grosell, M., and Weihrauch, D. (2010). Gastro-intestinal handling of water and solutes in three species of elasmobranch fish, the white-spotted bamboo shark, Chiloscyllium plagiosum, little skate, Leucoraja erinacea and the clear nose skate Raja eglanteria. Comparative Biochemistry and Physiology A Mol. Integr. Physiol. 155, 493-502.

Before 2010

Weihrauch, D., Wilkie, M.P., and Walsh, P.J. (2009). Ammonia and urea transporters in the gills of fish and aquatic crustaceans. Journal of Experimental Biology, 212 1716-30. Highlighted in: Inside JEB, 2009 by Kathryn Knight.

Piermarini, P.M., Weihrauch, D., Meyer, H., Huss, M., and Beyenbach, K.W. (2009). NHE8 is an intracellular cation/H+ exchanger in renal tubules of the yellow fever mosquito Aedes aegypti. American Journal of Physiology . Renal Physiology, 296 (4), F730-50.

Blaesse A.-K., Edwards S.L., Towle D.W., and Weihrauch D. (2009). Gene expression and localization of the rhesus-related ammonium transporter in green crabs (Carcinus maenas) exposed to ammonia. Bulletin of the Mount Desert Island Biological Laboratory 48, 12-13.

Jayasundara, N., Towle, D.W., Weihrauch, D., and Spanings-Pierrot, C. (2007). Gill-specific transcriptional regulation of Na+/K+-ATPase {alpha}-subunit in the euryhaline shore crab Pachygrapsus marmoratus: sequence variants and promoter structure. Journal of Experimental Biology.15, 2070-81.

Weihrauch, D., Kanchanapoo, J., Ao, M., Prasad, R., Piyachaturawat, P., and Rao, M.C. (2006). Weanling but not adult rabbit colon absorbs bile acids: Flux linked to expression of putative bile acid transporters. American Journal of Physiology, Gastrointestinal and Liver Physiology, G439-50.

Weihrauch, D. (2006). Active ammonia absorption in the midgut of the larvae of the tobacco hornworm Manduca sexta L.: Transport studies and mRNA expression analysis of a Rhesus-like ammonia transporter. Insect Biochemistry and Molecular Biology 36, 808-821.

Weihrauch, D., McNamara, J.C., Towle, D.W., and Onken, H. (2004). Ion-motive ATPases and active, transbranchial NaCl uptake in the red freshwater crab, Dilocarcinus pagei (Decapoda, Trichodactylidae). Journal of Experimental Biology 207, 4623-4631.

Luquet, C. M., Weihrauch, D., Senek. M., and Towle, D.W. (2005). Induction of branchial ion transporter mRNA expression during acclimation to salinity change in the euryhaline crab Chasmagnathus granulatus. Journal of Experimental Biology, 208, 3627-36.

Weihrauch, D., Morris, S., and Towle, D.W. (2004). Ammonia excretion in aquatic and terrestrial crabs. Journal of Experimental Biology 207, 4491-4504.

Matkowskyj, K.A., Nathaniel, R., Prasad, R., Weihrauch, D., Rao, M.C., and Benya, R.V. (2004). Galanin contributes to the excess colonic fluid secretion observed in dextran sulfate sodium murine colitis. Inflammatory Bowel Dissease 10, 408-16.

Ziegler, A., Weihrauch, D., Hagedorn, M., Towle, D.W. and Bleher, R. (2004). Expression and polarity reversal of V-type H+-ATPase during the mineralization-demineralization cycle in Porcellio scaber sternal epithelial cells. Journal of Experimental Biology 207, 1749-56.

Henry, R.P., Gehnrich, S., Weihrauch, D. and Towle, D.W. (2003). Salinity-mediated carbonic anhydrase induction in the gills of the euryhaline green crab, Carcinus maenas. Comparative Biochemistry and Physiology A, 136, 243-58.

Hagedorn, M., Weihrauch, D.,Towle, D.W., and Ziegler, A. (2003). Molecular characterisation of the smooth endoplasmic reticulum Ca(2+)-ATPase of Porcellio scaber and its expression in sternal epithelia during the moult cycle. Journal of Experimental Biology 206, 2167-75.

Ziegler, A., Weihrauch, D., Towle, D.W., and Hagedorn, M. (2002). Expression of Ca2+-ATPase and Na+/Ca2+-exchanger is up regulated during epithelial Ca2+-transport in hypodermal cells of Porcellio scaber. Cell Calcium 32, 131-141.

Towle, D.W. and Weihrauch, D. (2001). Osmoregulation by gills of euryhaline crabs: Molecular analysis of transporters, American Zoologist 44, 770-780.

Towle, D.W., Paulsen, R.S., Weihrauch, D., Kordylewski, M., Salvador, C., Lignot, J.-H., and Spanings-Pierrot, C. (2001). Na+/K+-ATPase in gills of the blue crab Callinectes sapidus: cDNA sequencing and salinity-related expression of -subunit mRNA and protein. Journal of Experimental Biology 204, 4005-4012.

Weihrauch, D., Ziegler, A., Siebers, D. and Towle, D.W. (2001). Molecular characterization of V-type H+-ATPase (B-subunit) in gills of euryhaline crabs and its physiological role in osmoregulatory ion uptake. Journal of Experimental Biology 204, 25-37.

Weihrauch D., Spanings-Pierrot C., and Towle D.W. (2001). Sequence analysis and expression of arginine kinase mRNA an gills of the semi-terrestrial grapsid crab Pachygrapsus marmoratus. Mount Desert Island Biological Laboratory 40, 33-35.

Gehnrich S., Henry R.P., Weihrauch D. and Towle D.W. (2001). Identification of carbonic anhydrase isoforms in gills of the shore crab, and changes in their expression during acclimation to low salinity. Mount Desert Island Biological Laboratory 40, 114-115.

Kotlyar, S., Weihrauch, D., Paulsen, R.S., and Towle, D.W. (2000). Expression of arginine kinase enzyme activity and mRNA expression in gills of the euryhaline crabs Carcinus maenas and Callinectes sapidus. Journal of Experimental Biology 203, 2395-2404.

Postel, U., Becker, W., Brandt, A., Luck-Kopp, S., Riestenpatt, S., Weihrauch, D., and Siebers, D. (2000). Active osmoregulatory ion uptake across the pleopods of the isopod Idotea baltica (Pallas): electrophysiological measurements on isolated split endo- and exopodites mounted in a micro-Ussing chamber. Journal of Experimental Biology 203, 1141-1152.

Gehnrich S., Brooks C., Weihrauch D., Towle D.W., and Henry R.P. (2000). Alterations in carbonic anhydrase gene expression during low salinity adaptation in the shore crab Carcinus maenas. Bulletin of the Mount Desert Island Biological Laboratory 38, 28-29.

Gehnrich S., Brooks C., Weihrauch D., Towle D.W. and Henry R.P. (2000). Carbonic anhydrase in the hypodermis of the shore crab, Carcinus maenas, and its role in the post-molt calcification of the cuticle. Bulletin of the Mount Desert Island Biological Laboratory 38, 26-27.

Weihrauch D. Siebers D., and Towle D.W. (2000). Urea retention in the hemolymph of the shore crab Carcinus maenas during prolonged starvation and a first approach to identify a branchial urea transporter. MDIBL Bulletin 38, 19-20.

Weihrauch, D., Becker, W., Postel, U., Luck-Kopp, S., and Siebers, D. (1999). Potential of active excretion of ammonia in three differently haline species of crabs. Journal of Comparative Physiology B. 169: 25-37.

Postel, U., Petrausch, G., Riestenpatt, S., Weihrauch, D., Malykh, J., Becker, W., and Siebers, D. (1998). Inhibition of Na+/K+-ATPase and active ion-transport functions in the gills of the shore crab Carcinus maenas induced by cadmium. Marine Biolog 130, 407-416.

Weihrauch, D., Becker, W., Postel, U., Riestenpatt, S., and Siebers, D. (1998). Active excretion of ammonia across the gills of the shore crab Carcinus maenas and its relation to osmoregulatory ion uptake. Journal of Comparative Physiology B 168, 364-376.

Published books

Weihrauch, D. (1999). Zur Stickstoff-Exkretion aquatischer Brachyuren: Carcinus maenas (Linaeus 1758, Decapoda, Portunidae), Cancer pagurus Linnaeus 1758 (Decapoda, Cancridae) und Eriocheir sinensis H. Milne Edwards 1853 (Decapoda, Grapsidae). VWF Verlag für Wissenschaft und Forschung GmbH, Berlin. ISBN: 3-89700-061-X.

Upcoming Seminars

General seminar: Francis Zwiers — Friday, October 20 at 3:30 p.m., 527 Buller.

General seminar: Workshop - Image Proficiency — Monday, October 23 at 12:30 p.m., 304 Biological Sciences.

General seminar: Crackerjack Seminar - Christa Burstahler — Friday, October 27 at 3:30 p.m., 527 Buller.

General seminar: Crackerjack Seminar — Friday, October 27 at 3:30 p.m., 527 Buller.