Molecular and physiological characterization of the nitrogen transport system in Caenorhabditis elegans
| dc.contributor.author | Aida, Adlimoghaddam | |
| dc.contributor.examiningcommittee | Dr. William Diehl Jones Dr. Ann Karen Brassinga Dr. Michele Piercey-Normore | en_US |
| dc.contributor.supervisor | Dr. Dirk Weihrauch Department o Biological Sciences | en_US |
| dc.date.accessioned | 2015-09-04T01:52:04Z | |
| dc.date.available | 2015-09-04T01:52:04Z | |
| dc.date.issued | 2014-10-01 | en_US |
| dc.date.issued | 2014-12-15 | en_US |
| dc.degree.discipline | Biological Sciences | en_US |
| dc.degree.level | Doctor of Philosophy (Ph.D.) | en_US |
| dc.description.abstract | In this study, we investigated the mechanism of nitrogen excretion in the soil nematode Caenorhabditis elegans. Utilizing the scanning ion electrode technique (SIET), it was shown for the first time in nematodes that the excretory cell promotes a secretion of ions, including Na+, K+, H+ and Ca2+. In addition, observations from experiments exposing the animal to various environmental pH regimes suggested that the mode of ammonia excretion is dependent on acidification of the unstirred boundary layer, supported also by a detected H+-net-excretion over the hypodermis employing SIET. Pharmacological experiments, SIET and enzyme activity measurements implicated the participation of a functional microtubule network, V-type H+-ATPase, carbonic anhydrase, Na+/K+-ATPase, and apical Na+-channels in the ammonia excretion mechanism of this roundworm. Most importantly, employing ammonia transporter deficient Saccharomyces cerevisiae we were able to show for the first time that an invertebrate Rh-like protein (Rhr-1) does indeed function as an ammonia transporter. Further, a second Rh-protein, Rhr-2, was found to be predominantly expressed in the hypodermis. Knock-out experiments on this transporter further suggested participation of Rhr-2 in the apical ammonia trapping mechanism. Overall, the results of this study provided evidence for a novel ammonia excretion mechanism over the hypodermis, which exhibits features commonly seen in both freshwater (ammonia trapping) and seawater inhabiting species (vesicular transport and exocytosis). | en_US |
| dc.description.note | October 2015 | en_US |
| dc.identifier.citation | Adlimoghaddam, A., Weihrauch, D., & 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. Journal of Experimental Biology, 217(23), 4119-4122. | en_US |
| dc.identifier.citation | Adlimoghaddam, A., Boeckstaens, M., Marini, A. M., Treberg, J. R., Brassinga, A. K. C., & Weihrauch, D. (2015). Ammonia excretion in Caenorhabditis elegans: mechanism and evidence of ammonia transport of the Rhesus protein CeRhr-1. Journal of Experimental Biology, 218(5), | en_US |
| dc.identifier.uri | http://hdl.handle.net/1993/30721 | |
| dc.language.iso | eng | en_US |
| dc.publisher | Journal of experimental biology (JEB) | en_US |
| dc.rights | open access | en_US |
| dc.subject | Ammonia, Toxic, Transport system, Caenorhabditis elegans | en_US |
| dc.title | Molecular and physiological characterization of the nitrogen transport system in Caenorhabditis elegans | en_US |
| dc.type | doctoral thesis | en_US |