{"id":{"repo_id":"creighton","oai_identifier":"oai:cdr.creighton.edu:10504/55719"},"canonical_url":"https://search.dev.ndltd.org/etd/creighton/oai:cdr.creighton.edu:10504/55719","repository":{"repo_id":"creighton","name":"Creighton University","base_url":"https://cdr.creighton.edu/server/oai/request"},"display":{"title":"Physiological, Biochemical, and Molecular Biological Effects of +4⁰C Acclimation on the Antarctic Teleost Trematomus bernacchii","abstract":"The Antarctic teleost Trematomus bemacchii lives in the waters surrounding Antarctica which are a constant -1.8°C. As an adaptive property they possess a uniquely high serum osmolality of -600 mOsm kg\"1 which is nearly double that of temperate teleosts. Acclimation of the T. bemacchii to +4°C results in a 25% decrease in serum osmolality and a doubling of activity of the ion pump in the gill, the Na+,K+-ATPase, that is energetically responsible for osmoregulation. The Na+,K+-ATPase consists of two obligate subunits (a catalytic a and membrane trafficking ß), however in some systems an accessory (y) subunit has also been shown to colocalize with the obligate subunits.|The a subunit is the active enzymatic portion and consists of 4 isoforms with differing biochemical properties. The affinity of the a3 for Na+ is less than that of the al and a2. However, all isoforms have similar affinities for K+ and ATP. Protein and mRNA of the al, a2, and a3 isoforms of Na+,K+-ATPase were previously reported in T. bemacchii gill. The effects of +4°C acclimation were investigated by measuring serum osmolality, oxygen consumption, substrate concentration dependent activation of the Na+,K+- ATPase, and ouabain inhibition of phosphoenzyme intermediate formation. Acclimation to +4°C caused the T. bemacchii to significantly decrease its serum osmolality from 581 + 11 mOsm kg\"1 at -1.5°C to 477 + 4 mOsm kg'1 at +4°C. The apparent affinity of the enzyme for sodium increased significantly (K'Na of 2.3 + 0.2 mM to 1.5 + 0.3 mM) with +4°C acclimation but the apparent affinity for potassium and ATP showed no change. Concentration dependent inhibition of the formation of phosphoenzyme intermediate of Na+,K+-ATPase by ouabain indicated the contribution of a3 to total Na+,K\"l\"-ATPase decreased from 33.72 + 13.03% to 0 + 6.67% while al and a2 increased from 33.12 + 12.72% and 33.15 + 0.30% to 44.87 + 6.67% and 55.12 + 6.67%, respectively upon +4°C acclimation. This is the first report of the application of a functional biochemical assay to characterize an environmental physiological change in this organism. The a3 isoform of Na+,K+-ATPase was of particular interest. Gene specific primers for the a3 were designed and the sequence of the a3 determined. The T. bernacchii a3 isoform amino acid sequence showed 86% identity to the a3 isoform sequence from mammals and 87% to the sequence of the a3 isoform from other fishes (individual identity was as high as 91% when compared to Tilcipia mossambica). These results suggest that the T. bernacchii reduce serum osmolality in response to increased environmental temperature by altering the cell surface Na+,K+-ATPase a subunit composition.","abstract_html":"The Antarctic teleost Trematomus bemacchii lives in the waters surrounding Antarctica which are a constant -1.8°C. As an adaptive property they possess a uniquely high serum osmolality of -600 mOsm kg"1 which is nearly double that of temperate teleosts. Acclimation of the T. bemacchii to +4°C results in a 25% decrease in serum osmolality and a doubling of activity of the ion pump in the gill, the Na+,K+-ATPase, that is energetically responsible for osmoregulation. The Na+,K+-ATPase consists of two obligate subunits (a catalytic a and membrane trafficking ß), however in some systems an accessory (y) subunit has also been shown to colocalize with the obligate subunits.|The a subunit is the active enzymatic portion and consists of 4 isoforms with differing biochemical properties. The affinity of the a3 for Na+ is less than that of the al and a2. However, all isoforms have similar affinities for K+ and ATP. Protein and mRNA of the al, a2, and a3 isoforms of Na+,K+-ATPase were previously reported in T. bemacchii gill. The effects of +4°C acclimation were investigated by measuring serum osmolality, oxygen consumption, substrate concentration dependent activation of the Na+,K+- ATPase, and ouabain inhibition of phosphoenzyme intermediate formation. Acclimation to +4°C caused the T. bemacchii to significantly decrease its serum osmolality from 581 + 11 mOsm kg"1 at -1.5°C to 477 + 4 mOsm kg'1 at +4°C. The apparent affinity of the enzyme for sodium increased significantly (K'Na of 2.3 + 0.2 mM to 1.5 + 0.3 mM) with +4°C acclimation but the apparent affinity for potassium and ATP showed no change. Concentration dependent inhibition of the formation of phosphoenzyme intermediate of Na+,K+-ATPase by ouabain indicated the contribution of a3 to total Na+,K"l"-ATPase decreased from 33.72 + 13.03% to 0 + 6.67% while al and a2 increased from 33.12 + 12.72% and 33.15 + 0.30% to 44.87 + 6.67% and 55.12 + 6.67%, respectively upon +4°C acclimation. This is the first report of the application of a functional biochemical assay to characterize an environmental physiological change in this organism. The a3 isoform of Na+,K+-ATPase was of particular interest. Gene specific primers for the a3 were designed and the sequence of the a3 determined. The T. bernacchii a3 isoform amino acid sequence showed 86% identity to the a3 isoform sequence from mammals and 87% to the sequence of the a3 isoform from other fishes (individual identity was as high as 91% when compared to Tilcipia mossambica). These results suggest that the T. bernacchii reduce serum osmolality in response to increased environmental temperature by altering the cell surface Na+,K+-ATPase a subunit composition.","abstract_has_math":false,"creators":["Morrison, John Francis"],"institution":"Creighton University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Petzel, David H."],"committee_chairs":[],"committee_members":[],"year":2005,"date_issued":"2005","date_published":"2005","updated_at":"2026-07-24T01:51:52Z","subjects":[],"languages":["en_US"],"rights":["Copyright is retained by the Author. A non-exclusive distribution right is granted to Creighton University and to ProQuest following the publishing model selected above."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10504/55719","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Petzel, David H."]},{"key":"dc:creator","label":"Author","values":["Morrison, John Francis"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-06-25T21:17:27Z"]},{"key":"dc:date.issued","label":"Date","values":["2005"]},{"key":"dc:publisher","label":"Institution","values":["Creighton University"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright is retained by the Author. A non-exclusive distribution right is granted to Creighton University and to ProQuest following the publishing model selected above."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10504/55719"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The Antarctic teleost Trematomus bemacchii lives in the waters surrounding Antarctica which are a constant -1.8°C. As an adaptive property they possess a uniquely high serum osmolality of -600 mOsm kg\"1 which is nearly double that of temperate teleosts. Acclimation of the T. bemacchii to +4°C results in a 25% decrease in serum osmolality and a doubling of activity of the ion pump in the gill, the Na+,K+-ATPase, that is energetically responsible for osmoregulation. The Na+,K+-ATPase consists of two obligate subunits (a catalytic a and membrane trafficking ß), however in some systems an accessory (y) subunit has also been shown to colocalize with the obligate subunits.|The a subunit is the active enzymatic portion and consists of 4 isoforms with differing biochemical properties. The affinity of the a3 for Na+ is less than that of the al and a2. However, all isoforms have similar affinities for K+ and ATP. Protein and mRNA of the al, a2, and a3 isoforms of Na+,K+-ATPase were previously reported in T. bemacchii gill. The effects of +4°C acclimation were investigated by measuring serum osmolality, oxygen consumption, substrate concentration dependent activation of the Na+,K+- ATPase, and ouabain inhibition of phosphoenzyme intermediate formation. Acclimation to +4°C caused the T. bemacchii to significantly decrease its serum osmolality from 581 + 11 mOsm kg\"1 at -1.5°C to 477 + 4 mOsm kg'1 at +4°C. The apparent affinity of the enzyme for sodium increased significantly (K'Na of 2.3 + 0.2 mM to 1.5 + 0.3 mM) with +4°C acclimation but the apparent affinity for potassium and ATP showed no change. Concentration dependent inhibition of the formation of phosphoenzyme intermediate of Na+,K+-ATPase by ouabain indicated the contribution of a3 to total Na+,K\"l\"-ATPase decreased from 33.72 + 13.03% to 0 + 6.67% while al and a2 increased from 33.12 + 12.72% and 33.15 + 0.30% to 44.87 + 6.67% and 55.12 + 6.67%, respectively upon +4°C acclimation. This is the first report of the application of a functional biochemical assay to characterize an environmental physiological change in this organism. The a3 isoform of Na+,K+-ATPase was of particular interest. Gene specific primers for the a3 were designed and the sequence of the a3 determined. The T. bernacchii a3 isoform amino acid sequence showed 86% identity to the a3 isoform sequence from mammals and 87% to the sequence of the a3 isoform from other fishes (individual identity was as high as 91% when compared to Tilcipia mossambica). These results suggest that the T. bernacchii reduce serum osmolality in response to increased environmental temperature by altering the cell surface Na+,K+-ATPase a subunit composition."]},{"key":"dc:title","label":"Title","values":["Physiological, Biochemical, and Molecular Biological Effects of +4⁰C Acclimation on the Antarctic Teleost Trematomus bernacchii"]}]}],"canonical_facts":{"dc:contributor.advisor":["Petzel, David H."],"dc:creator":["Morrison, John Francis"],"dc:date.accessioned":["2014-06-25T21:17:27Z"],"dc:date.issued":["2005"],"dc:description.abstract":["The Antarctic teleost Trematomus bemacchii lives in the waters surrounding Antarctica which are a constant -1.8°C. As an adaptive property they possess a uniquely high serum osmolality of -600 mOsm kg\"1 which is nearly double that of temperate teleosts. Acclimation of the T. bemacchii to +4°C results in a 25% decrease in serum osmolality and a doubling of activity of the ion pump in the gill, the Na+,K+-ATPase, that is energetically responsible for osmoregulation. The Na+,K+-ATPase consists of two obligate subunits (a catalytic a and membrane trafficking ß), however in some systems an accessory (y) subunit has also been shown to colocalize with the obligate subunits.|The a subunit is the active enzymatic portion and consists of 4 isoforms with differing biochemical properties. The affinity of the a3 for Na+ is less than that of the al and a2. However, all isoforms have similar affinities for K+ and ATP. Protein and mRNA of the al, a2, and a3 isoforms of Na+,K+-ATPase were previously reported in T. bemacchii gill. The effects of +4°C acclimation were investigated by measuring serum osmolality, oxygen consumption, substrate concentration dependent activation of the Na+,K+- ATPase, and ouabain inhibition of phosphoenzyme intermediate formation. Acclimation to +4°C caused the T. bemacchii to significantly decrease its serum osmolality from 581 + 11 mOsm kg\"1 at -1.5°C to 477 + 4 mOsm kg'1 at +4°C. The apparent affinity of the enzyme for sodium increased significantly (K'Na of 2.3 + 0.2 mM to 1.5 + 0.3 mM) with +4°C acclimation but the apparent affinity for potassium and ATP showed no change. Concentration dependent inhibition of the formation of phosphoenzyme intermediate of Na+,K+-ATPase by ouabain indicated the contribution of a3 to total Na+,K\"l\"-ATPase decreased from 33.72 + 13.03% to 0 + 6.67% while al and a2 increased from 33.12 + 12.72% and 33.15 + 0.30% to 44.87 + 6.67% and 55.12 + 6.67%, respectively upon +4°C acclimation. This is the first report of the application of a functional biochemical assay to characterize an environmental physiological change in this organism. The a3 isoform of Na+,K+-ATPase was of particular interest. Gene specific primers for the a3 were designed and the sequence of the a3 determined. The T. bernacchii a3 isoform amino acid sequence showed 86% identity to the a3 isoform sequence from mammals and 87% to the sequence of the a3 isoform from other fishes (individual identity was as high as 91% when compared to Tilcipia mossambica). These results suggest that the T. bernacchii reduce serum osmolality in response to increased environmental temperature by altering the cell surface Na+,K+-ATPase a subunit composition."],"dc:identifier.uri":["http://hdl.handle.net/10504/55719"],"dc:language.iso":["en_US"],"dc:publisher":["Creighton University"],"dc:rights":["Copyright is retained by the Author. A non-exclusive distribution right is granted to Creighton University and to ProQuest following the publishing model selected above."],"dc:title":["Physiological, Biochemical, and Molecular Biological Effects of +4⁰C Acclimation on the Antarctic Teleost Trematomus bernacchii"],"dc:type":["Thesis"]},"updated_at":"2026-07-24T01:51:52Z"}