Acid-base regulation and ammonia excretion in the American horseshoe crab, Limulus polyphemus
dc.contributor.author | Hans, Stephanie | |
dc.contributor.examiningcommittee | Anderson, Gary (Biological Sciences) Hausner, Georg (Microbiology) | en_US |
dc.contributor.supervisor | Weihrauch, Dirk (Biological Sciences) | en_US |
dc.date.accessioned | 2016-09-15T15:54:25Z | |
dc.date.available | 2016-09-15T15:54:25Z | |
dc.date.issued | 2016 | |
dc.degree.discipline | Biological Sciences | en_US |
dc.degree.level | Master of Science (M.Sc.) | en_US |
dc.description.abstract | Acid-base regulation is vital for animals and while the inorganic carbon system largely determines body fluid pH, another potentially valuable acid-base pair is ammonia (NH4+/NH3). This study focuses on the American horseshoe crab (Limulus polyphemus), a phylogenetically ancient marine chelicerate with no published studies on its acid-base physiology. Physiological and molecular analyses indicate that Na+/K+-ATPase, Rhesus-protein (Rh), and carbonic anhydrase (CA) are involved in acid-base homeostasis and/or ammonia regulation. This likely occurs in the book gills, which consist of ultrastructurally distinct regions. The ventral half-lamella is ion-leaky and displayed high Rh-protein, cytoplasmic CA, and hyperpolarization-activated cyclic nucleotide-gated K+ channel mRNA expression levels, suggesting a specialization in facilitated CO2 and/or ammonia diffusion compared to the dorsal half-lamella. During hypercapnia acclimation, hemolymph acid-base status exhibited a compensated respiratory acidosis accompanied with signs of metabolic depression. Ammonia influx associated with high environmental ammonia acclimation was successfully counteracted, but induced modifications in acid-base homeostasis. | en_US |
dc.description.note | October 2016 | en_US |
dc.identifier.uri | http://hdl.handle.net/1993/31775 | |
dc.language.iso | eng | en_US |
dc.rights | open access | en_US |
dc.subject | Acid-base regulation | en_US |
dc.subject | Ammonia | en_US |
dc.subject | Hypercapnia | en_US |
dc.subject | Book gills | en_US |
dc.title | Acid-base regulation and ammonia excretion in the American horseshoe crab, Limulus polyphemus | en_US |
dc.type | master thesis | en_US |