USAP-DC

{"dp_type": "Dataset", "free_text": "Icefish"}

[{"awards": "2232891 Postlethwait, John; 1947040 Postlethwait, John; 1543383 Postlethwait, John", "bounds_geometry": ["POLYGON((-180 -37,-144 -37,-108 -37,-72 -37,-36 -37,0 -37,36 -37,72 -37,108 -37,144 -37,180 -37,180 -42.3,180 -47.6,180 -52.9,180 -58.2,180 -63.5,180 -68.8,180 -74.1,180 -79.4,180 -84.69999999999999,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -84.7,-180 -79.4,-180 -74.1,-180 -68.8,-180 -63.5,-180 -58.2,-180 -52.9,-180 -47.6,-180 -42.300000000000004,-180 -37))"], "date_created": "Fri, 08 Sep 2023 00:00:00 GMT", "description": "Phylogenetic tree of Notothenioid species used in analyses and results of the HyPhy aBSREL tests for diversifying selection in notothenioid hemoglobin genes in the research article \u201cCold-driven hemoglobin evolution in Antarctic notothenioid fishes prior to hemoglobin gene loss in white-blooded icefishes\u201d by Thomas Desvignes, Iliana Bista, Karina Herrera, Audrey Landes, John H. Postlethwait.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Gene; Genetic Analysis; Hemoglobin; Icefish; Notothenioid; Notothenioid Fishes; Plunderfish; Sub-Antarctic", "locations": "Antarctica; Sub-Antarctic; Antarctica", "north": -37.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Desvignes, Thomas; Postlethwait, John", "project_titles": "Evolution of hemoglobin genes in notothenioid fishes", "projects": [{"proj_uid": "p0010417", "repository": "USAP-DC", "title": "Evolution of hemoglobin genes in notothenioid fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "aBSREL tests for episodic diversifying selection on hemoglobin genes in notothenioids.", "uid": "601728", "west": -180.0}, {"awards": "1543383 Postlethwait, John; 1947040 Postlethwait, John; 2232891 Postlethwait, John", "bounds_geometry": ["POLYGON((-180 -37,-144 -37,-108 -37,-72 -37,-36 -37,0 -37,36 -37,72 -37,108 -37,144 -37,180 -37,180 -42.3,180 -47.6,180 -52.9,180 -58.2,180 -63.5,180 -68.8,180 -74.1,180 -79.4,180 -84.69999999999999,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -84.7,-180 -79.4,-180 -74.1,-180 -68.8,-180 -63.5,-180 -58.2,-180 -52.9,-180 -47.6,-180 -42.300000000000004,-180 -37))"], "date_created": "Fri, 08 Sep 2023 00:00:00 GMT", "description": "Notothenioid hemoglobin protein 3D modeling using SWISS-MODEL in the research article \u201cCold-driven hemoglobin evolution in Antarctic notothenioid fishes prior to hemoglobin gene loss in white-blooded icefishes\u201d by Thomas Desvignes, Iliana Bista, Karina Herrera, Audrey Landes, John H. Postlethwait.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Genetic Analysis; Hemoglobin; Icefish; Notothenioid; Notothenioid Fishes; Plunderfish; Sub-Antarctic", "locations": "Sub-Antarctic; Antarctica", "north": -37.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Desvignes, Thomas; Postlethwait, John", "project_titles": "Evolution of hemoglobin genes in notothenioid fishes", "projects": [{"proj_uid": "p0010417", "repository": "USAP-DC", "title": "Evolution of hemoglobin genes in notothenioid fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Notothenioid hemoglobin protein 3D modeling.", "uid": "601732", "west": -180.0}, {"awards": "1543383 Postlethwait, John; 1947040 Postlethwait, John; 2232891 Postlethwait, John", "bounds_geometry": ["POLYGON((-180 -37,-144 -37,-108 -37,-72 -37,-36 -37,0 -37,36 -37,72 -37,108 -37,144 -37,180 -37,180 -42.3,180 -47.6,180 -52.9,180 -58.2,180 -63.5,180 -68.8,180 -74.1,180 -79.4,180 -84.69999999999999,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -84.7,-180 -79.4,-180 -74.1,-180 -68.8,-180 -63.5,-180 -58.2,-180 -52.9,-180 -47.6,-180 -42.300000000000004,-180 -37))"], "date_created": "Fri, 08 Sep 2023 00:00:00 GMT", "description": "Phylogenetic tree of Notothenioid species used in analyses and results of the HyPhy RELAX tests for pervasive changes in strength of natural selection on hemoglobin genes in the research article \u201cCold-driven hemoglobin evolution in Antarctic notothenioid fishes prior to hemoglobin gene loss in white-blooded icefishes\u201d by Thomas Desvignes, Iliana Bista, Karina Herrera, Audrey Landes, John H. Postlethwait.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Genetic Analysis; Hemoglobin; Icefish; Notothenioid; Notothenioid Fishes; Plunderfish; Sub-Antarctic", "locations": "Antarctica; Sub-Antarctic", "north": -37.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Desvignes, Thomas; Postlethwait, John", "project_titles": "Evolution of hemoglobin genes in notothenioid fishes", "projects": [{"proj_uid": "p0010417", "repository": "USAP-DC", "title": "Evolution of hemoglobin genes in notothenioid fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "RELAX tests for pervasive changes in strength of natural selection on hemoglobin genes in notothenioids.", "uid": "601731", "west": -180.0}, {"awards": "2232891 Postlethwait, John; 1543383 Postlethwait, John; 1947040 Postlethwait, John", "bounds_geometry": ["POLYGON((-180 -37,-144 -37,-108 -37,-72 -37,-36 -37,0 -37,36 -37,72 -37,108 -37,144 -37,180 -37,180 -42.3,180 -47.6,180 -52.9,180 -58.2,180 -63.5,180 -68.8,180 -74.1,180 -79.4,180 -84.69999999999999,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -84.7,-180 -79.4,-180 -74.1,-180 -68.8,-180 -63.5,-180 -58.2,-180 -52.9,-180 -47.6,-180 -42.300000000000004,-180 -37))"], "date_created": "Fri, 08 Sep 2023 00:00:00 GMT", "description": "Phylogenetic tree of Notothenioid species used in analyses and results of the HyPhy MEME tests for sites evolving under episodic diversifying selection in notothenioid hemoglobin genes in the research article \u201cCold-driven hemoglobin evolution in Antarctic notothenioid fishes prior to hemoglobin gene loss in white-blooded icefishes\u201d by Thomas Desvignes, Iliana Bista, Karina Herrera, Audrey Landes, John H. Postlethwait.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Genetic Analysis; Hemoglobin; Icefish; Notothenioid; Notothenioid Fishes; Plunderfish; Sub-Antarctic", "locations": "Antarctica; Sub-Antarctic", "north": -37.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Desvignes, Thomas; Postlethwait, John", "project_titles": "Evolution of hemoglobin genes in notothenioid fishes", "projects": [{"proj_uid": "p0010417", "repository": "USAP-DC", "title": "Evolution of hemoglobin genes in notothenioid fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "MEME tests of sites evolving under episodic diversifying selection in notothenioid hemoglobin genes.", "uid": "601730", "west": -180.0}, {"awards": "2232891 Postlethwait, John; 1543383 Postlethwait, John; 1947040 Postlethwait, John", "bounds_geometry": ["POLYGON((-180 -37,-144 -37,-108 -37,-72 -37,-36 -37,0 -37,36 -37,72 -37,108 -37,144 -37,180 -37,180 -42.3,180 -47.6,180 -52.9,180 -58.2,180 -63.5,180 -68.8,180 -74.1,180 -79.4,180 -84.69999999999999,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -84.7,-180 -79.4,-180 -74.1,-180 -68.8,-180 -63.5,-180 -58.2,-180 -52.9,-180 -47.6,-180 -42.300000000000004,-180 -37))"], "date_created": "Fri, 08 Sep 2023 00:00:00 GMT", "description": "Results of hemoglobin gene KaKs (dN/dS) analyses in notothenioids in the research article \u201cCold-driven hemoglobin evolution in Antarctic notothenioid fishes prior to hemoglobin gene loss in white-blooded icefishes\u201d by Thomas Desvignes, Iliana Bista, Karina Herrera, Audrey Landes, John H. Postlethwait.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Genetic Analysis; Hemoglobin; Icefish; Notothenioid; Notothenioid Fishes; Plunderfish; Sub-Antarctic", "locations": "Sub-Antarctic; Antarctica", "north": -37.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Desvignes, Thomas; Postlethwait, John", "project_titles": "Evolution of hemoglobin genes in notothenioid fishes", "projects": [{"proj_uid": "p0010417", "repository": "USAP-DC", "title": "Evolution of hemoglobin genes in notothenioid fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Rates of hemoglobin evolution among genes and across notothenioid species.", "uid": "601729", "west": -180.0}, {"awards": "2232891 Postlethwait, John; 1947040 Postlethwait, John; 1543383 Postlethwait, John", "bounds_geometry": ["POLYGON((-180 -37,-144 -37,-108 -37,-72 -37,-36 -37,0 -37,36 -37,72 -37,108 -37,144 -37,180 -37,180 -42.3,180 -47.6,180 -52.9,180 -58.2,180 -63.5,180 -68.8,180 -74.1,180 -79.4,180 -84.69999999999999,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -84.7,-180 -79.4,-180 -74.1,-180 -68.8,-180 -63.5,-180 -58.2,-180 -52.9,-180 -47.6,-180 -42.300000000000004,-180 -37))"], "date_created": "Thu, 24 Aug 2023 00:00:00 GMT", "description": "All input and output files of the phylogenetic trees of hemoglobin proteins in Notothenioids from the study \"Cold-driven hemoglobin evolution in Antarctic notothenioid fishes prior to hemoglobin gene loss in white-blooded icefishes\" by Thomas Desvignes, Iliana Bista, Karina Herrera, Audrey Landes, and John H. Postlethwait.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Gene; Hemoglobin; Icefish; Notothenioid; Plunderfish; Sub-Antarctic", "locations": "Sub-Antarctic; Antarctica", "north": -37.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Desvignes, Thomas; Postlethwait, John", "project_titles": "Evolution of hemoglobin genes in notothenioid fishes", "projects": [{"proj_uid": "p0010417", "repository": "USAP-DC", "title": "Evolution of hemoglobin genes in notothenioid fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Phylogenetic trees of hemoglobin proteins in notothenioids from the study \"Cold-driven hemoglobin evolution in Antarctic notothenioid fishes prior to hemoglobin gene loss in white-blooded icefishes\"", "uid": "601722", "west": -180.0}, {"awards": "2232891 Postlethwait, John; 1947040 Postlethwait, John; 1543383 Postlethwait, John", "bounds_geometry": ["POLYGON((-180 -37,-144 -37,-108 -37,-72 -37,-36 -37,0 -37,36 -37,72 -37,108 -37,144 -37,180 -37,180 -42.3,180 -47.6,180 -52.9,180 -58.2,180 -63.5,180 -68.8,180 -74.1,180 -79.4,180 -84.69999999999999,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -84.7,-180 -79.4,-180 -74.1,-180 -68.8,-180 -63.5,-180 -58.2,-180 -52.9,-180 -47.6,-180 -42.300000000000004,-180 -37))"], "date_created": "Thu, 24 Aug 2023 00:00:00 GMT", "description": "Phylogenetic tree of 36 notothenioid species and five outgroup used throughout the study \"Cold-driven hemoglobin evolution in Antarctic notothenioid fishes prior to hemoglobin gene loss in white-blooded icefishes\" by Thomas Desvignes, Iliana Bista, Karina Herrera, Audrey Landes, John H. Postlethwait.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Gene; Hemoglobin; Icefish; Notothenioid; Plunderfish; Sub-Antarctic", "locations": "Sub-Antarctic; Antarctica", "north": -37.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Desvignes, Thomas; Postlethwait, John", "project_titles": "Evolution of hemoglobin genes in notothenioid fishes", "projects": [{"proj_uid": "p0010417", "repository": "USAP-DC", "title": "Evolution of hemoglobin genes in notothenioid fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Notothenioid species tree used in the study \"Cold-driven hemoglobin evolution in Antarctic notothenioid fishes prior to hemoglobin gene loss in white-blooded icefishes\"", "uid": "601721", "west": -180.0}, {"awards": "1341663 O\u0027Brien, Kristin; 1341602 Crockett, Elizabeth", "bounds_geometry": null, "date_created": "Thu, 24 Dec 2020 00:00:00 GMT", "description": "Antarctic notothenioids are noted for extreme stenothermy, yet underpinnings of their thermal limits are not fully understood. We hypothesized that properties of ventricular membranes could explain previously observed differences among notothenioids in temperature onset of cardiac arrhythmias and persistent asystole. Microsomes were prepared using ventricles from six species of notothenioids, including four species from the hemoglobin-less (Hb-) family Channichthyidae (icefishes), which also differentially express cardiac myoglobin (Mb), and two species from the (Hb+) Nototheniidae. We determined membrane fluidity and structural integrity by quantifying fluorescence depolarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) and leakage of 5(6)-carboxyfluorescein, respectively, over a temperature range from ambient (0 \u00b0C) to 20 \u00b0C. Compositions of membrane phospholipids and cholesterol contents were also quantified. Membranes from all four species of icefishes exhibited greater fluidity than membranes from the red-blooded species N. coriiceps. Thermal sensitivity of fluidity did not vary among species. The greatest thermal sensitivity to leakage occurred between 0 and 5 \u00b0C for all species, while membranes from the icefish, Chaenocephalus aceratus (Hb-/Mb-) displayed leakage that was nearly 1.5-fold greater than leakage in N. coriiceps (Hb+/Mb+). Contents of phosphatidylethanolamine (PE) were approximately 1.5-fold greater in icefishes than in red-blooded fishes, and phospholipids had a higher degree of unsaturation in icefishes than in Hb + notothenioids. Cholesterol contents were lowest in Champsocephalus gunnari (Hb-/Mb-) and highest in the two Hb+/Mb + species, G. gibberifrons and N. coriiceps. Our results reveal marked differences in membrane properties and indicate a breach in membrane fluidity and structural integrity at a lower temperature in icefishes than in red-blooded notothenioids. ", "east": null, "geometry": null, "keywords": "Antarctica; Antarctic Peninsula", "locations": "Antarctica; Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "O\u0027Brien, Kristin; Evans, Elizabeth; Farnoud, Amir; Crockett, Elizabeth", "project_titles": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes", "projects": [{"proj_uid": "p0010084", "repository": "USAP-DC", "title": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Thermal sensitivity of membrane fluidity and integrity in hearts of Antarctic fishes that vary in expression of hemoglobin and myoglobin", "uid": "601414", "west": null}, {"awards": "1341663 O\u0027Brien, Kristin; 1341602 Crockett, Elizabeth", "bounds_geometry": null, "date_created": "Fri, 18 Dec 2020 00:00:00 GMT", "description": "We tested the hypothesis that blackfin icefish (Chaenocephalus aceratus), one of the six species in the family Channichthyidae (the icefishes) that do not express haemoglobin and myoglobin, lack regulatory cardiovascular flexibility during acute warming and activity. The experimental protocols were designed to optimize the surgical protocol and minimize stress. First, minimally invasive heart rate (fH) measurements were made during a thermal ramp until cardiac failure in C. aceratus and compared with those from the closely related red-blooded black rockcod (Notothenia coriiceps). Then, integrative cardiovascular adjustments were more extensively studied using flow probes and intravascular catheters in C. aceratus during acute warming (from 0 to 8\u00b0C) at rest and after imposed activity. Chaenocephalus aceratus had a lower routine fH than N. coriiceps (9 beats min-1 versus 14 beats min-1) and a lower peak fH during acute warming (38 beats min-1 versus 55 beats min-1) with a similar cardiac breakpoint temperature (13 and 14\u00b0C, respectively). Routine cardiac output (Q\u0307) for C. aceratus at \u223c0\u00b0C was much lower (26.6 ml min-1 kg-1) than previously reported, probably because fish in the present study had a low fH (12 beats min-1) indicative of a high routine vagal tone and low stress. Chaenocephalus aceratus increased oxygen consumption during acute warming and with activity. Correspondingly, Q\u0307 increased considerably (maximally 86.3 ml min-1 kg-1), as did vascular conductance (5-fold). Thus, unlike earlier suggestions, these data provide convincing evidence that icefish can mount a well-developed cardiovascular regulation of heart rate, cardiac output and vascular conductance, and this regulatory capacity provides flexibility during acute warming. ", "east": null, "geometry": null, "keywords": "Antarctica; Antarctic Peninsula; Biota; Fish", "locations": "Antarctic Peninsula; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Joyce, William; Farrell, Anthony; Axelsson, Michael; Egginton, Stuart; Crockett, Elizabeth; O\u0027Brien, Kristin", "project_titles": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes", "projects": [{"proj_uid": "p0010084", "repository": "USAP-DC", "title": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Effects of acute warming on cardiovascular performance of Antarctic fishes", "uid": "601410", "west": null}, {"awards": "1341663 O\u0027Brien, Kristin; 1341602 Crockett, Elizabeth", "bounds_geometry": null, "date_created": "Fri, 18 Dec 2020 00:00:00 GMT", "description": "Icefishes characteristically lack the oxygen-binding protein haemoglobin and therefore are especially reliant on cardiovascular regulation to augment oxygen transport when oxygen demand increases, such as during activity and warming. Using both in vivo and in vitro experiments, we evaluated the roles for adrenaline and adenosine, two well-established cardio- and vasoactive molecules, in regulating the cardiovascular system of the blackfin icefish, Chaenocephalus aceratus. Despite increasing cardiac contractility (increasing twitch force and contraction kinetics in isometric myocardial strip preparations) and accelerating heart rate (\u0192H), adrenaline (5 nmol kg-1 bolus intra-arterial injection) did not significantly increase cardiac output (Q\u0307) in vivo because it elicited a large decrease in vascular conductance (Gsys). In contrast, and despite preliminary data suggesting a direct negative inotropic effect of adenosine on isolated atria and little effect on isolated ventricle strips, adenosine (500 nmol kg-1) generated a large increase in Q\u0307 by increasing Gsys, a change reminiscent of that previously reported during both acute warming and invoked activity. Our data thus illustrate how Q\u0307 in C. aceratus may be much more dependent on peripheral control of vasomotor tone than direct regulation of the heart. ", "east": null, "geometry": null, "keywords": "Antarctica; Antarctic Peninsula", "locations": "Antarctic Peninsula; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Joyce, Michael; Axelsson, Michael; Farrell, Anthony; Egginton, Stuart; O\u0027Brien, Kristin", "project_titles": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes", "projects": [{"proj_uid": "p0010084", "repository": "USAP-DC", "title": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Adrenergic and adenosinergic regulation of the cardiovascular system in the Antarctic icefish Chaenocephalus aceratus", "uid": "601409", "west": null}, {"awards": "1341602 Crockett, Elizabeth; 1341663 O\u0027Brien, Kristin", "bounds_geometry": null, "date_created": "Fri, 18 Dec 2020 00:00:00 GMT", "description": "In fishes, the spleen can function as an important reservoir for red blood cells (RBCs), which, following splenic contraction, may be released into the circulation to increase haematocrit during energy\u2010demanding activities. This trait is particularly pronounced in red\u2010blooded Antarctic fishes in which the spleen can sequester a large proportion of RBCs during rest, thereby reducing blood viscosity, which may serve as an adaptation to life in cold environments. In one species, Pagothenia borchgrevinki, it has previously been shown that splenic contraction primarily depends on cholinergic stimulation. The aim of the present study was to investigate the regulation of splenic contraction in five other Antarctic fish species, three red\u2010blooded notothenioids (Dissostichus mawsoni Norman, 1937, Gobionotothen gibberifrons L\u00f6nnberg, 1905, Notothenia coriiceps Richardson 1844) and two white\u2010blooded \u201cicefish\u201d (Chaenocephalus aceratus L\u00f6nnberg, 1906 and Champsocephalus gunnari L\u00f6nnberg, 1905), which lack haemoglobin and RBCs, but nevertheless possess a large spleen. In all species, splenic strips constricted in response to both cholinergic (carbachol) and adrenergic (adrenaline) agonists. Surprisingly, in the two species of icefish, the spleen responded with similar sensitivity to red\u2010blooded species, despite contraction being of little obvious benefit for releasing RBCs into the circulation. Although the icefish lineage lost functional haemoglobin before diversifying over the past 7.8\u20134.8 millions of years, they retain the capacity to contract the spleen, likely as a vestige inherited from their red\u2010blooded ancestors.", "east": null, "geometry": null, "keywords": "Antarctica; Antarctic Peninsula", "locations": "Antarctic Peninsula; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "O\u0027Brien, Kristin; Joyce, William; Axelsson, Michael", "project_titles": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes", "projects": [{"proj_uid": "p0010084", "repository": "USAP-DC", "title": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Measurements of splenic contraction in Antarctic fishes", "uid": "601407", "west": null}, {"awards": "1341602 Crockett, Elizabeth; 1341663 O\u0027Brien, Kristin", "bounds_geometry": null, "date_created": "Fri, 18 Dec 2020 00:00:00 GMT", "description": "The ability of Antarctic notothenioid fishes to mount a robust molecular response to hypoxia is largely unknown. The transcription factor, hypoxia-inducible factor-1 (HIF-1), a heterodimer of HIF-1\u03b1 and HIF-1\u03b2 subunits, is the master regulator of oxygen homeostasis in most metazoans. We sought to determine if, in the hearts of Antarctic notothenioids, HIF-1 is activated and functional in response to either an acute heat stress or hypoxia. The red-blooded Notothenia coriiceps and the hemoglobinless icefish, Chaenocephalus aceratus, were exposed to their critical thermal maximum (CTMAX) or hypoxia (5.0 \u00b1 0.3 mg of O2 L-1) for 2 h. Additionally, N. coriiceps was exposed to 2.3 \u00b1 0.3 mg of O2 L-1 for 12 h, and red-blooded Gobionotothen gibberifrons was exposed to both levels of hypoxia. Levels of HIF-1\u03b1 were quantified in nuclei isolated from heart ventricles using western blotting. Transcript levels of genes involved in anaerobic metabolism, and known to be regulated by HIF-1, were quantified by real-time PCR, and lactate levels were measured in heart ventricles. Protein levels of HIF-1\u03b1 increase in nuclei of hearts of N. coriiceps and C. aceratus in response to exposure to CTMAX and in hearts of N. coriiceps exposed to severe hypoxia, yet mRNA levels of anaerobic metabolic genes do not increase in any species, nor do lactate levels increase, suggesting that HIF-1 does not stimulate metabolic remodeling in hearts of notothenioids under these conditions. Together, these data suggest that Antarctic notothenioids may be vulnerable to hypoxic events, which are likely to increase with climate warming. ", "east": null, "geometry": null, "keywords": "Antarctica; Antarctic Peninsula", "locations": "Antarctica; Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "O\u0027Brien, Kristin", "project_titles": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes", "projects": [{"proj_uid": "p0010084", "repository": "USAP-DC", "title": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Hypoxia response of hearts of Antarctic fishes", "uid": "601406", "west": null}, {"awards": "1341663 O\u0027Brien, Kristin", "bounds_geometry": null, "date_created": "Fri, 18 Dec 2020 00:00:00 GMT", "description": "Studies in temperate fishes provide evidence that cardiac mitochondrial function and the capacity to fuel cardiac work contribute to thermal tolerance. Here, we tested the hypothesis that decreased cardiac aerobic metabolic capacity contributes to the lower thermal tolerance of the haemoglobinless Antarctic icefish, Chaenocephalus aceratus, compared with that of the red-blooded Antarctic species, Notothenia coriiceps. Maximal activities of citrate synthase (CS) and lactate dehydrogenase (LDH), respiration rates of isolated mitochondria, adenylate levels and changes in mitochondrial protein expression were quantified from hearts of animals held at ambient temperature or exposed to their critical thermal maximum (CTmax). Compared with C. aceratus, activity of CS, ATP concentration and energy charge were higher in hearts of N. coriiceps at ambient temperature and CTmax While state 3 mitochondrial respiration rates were not impaired by exposure to CTmax in either species, state 4 rates, indicative of proton leakage, increased following exposure to CTmax in C. aceratus but not N. coriiceps The interactive effect of temperature and species resulted in an increase in antioxidants and aerobic metabolic enzymes in N. coriiceps but not in C. aceratus Together, our results support the hypothesis that the lower aerobic metabolic capacity of C. aceratus hearts contributes to its low thermal tolerance. ", "east": null, "geometry": null, "keywords": "Antarctica; Antarctic Peninsula", "locations": "Antarctic Peninsula; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "O\u0027Brien, Kristin", "project_titles": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes", "projects": [{"proj_uid": "p0010084", "repository": "USAP-DC", "title": "Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Cardiac metabolism in Antarctic fishes in response to an acute increase in temperature", "uid": "601405", "west": null}, {"awards": "1043576 Crockett, Elizabeth", "bounds_geometry": null, "date_created": "Tue, 13 Dec 2016 00:00:00 GMT", "description": "Positioning and depth recordings were made using instruments aboard the ARSV Laurence M Gould.", "east": null, "geometry": null, "keywords": "Antarctica; Biota; Southern Ocean", "locations": "Southern Ocean; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Crockett, Elizabeth", "project_titles": "Collaborative research: Redox Balance in Antarctic Notothenioid fishes: Do Icefishes have an Advantage?", "projects": [{"proj_uid": "p0000320", "repository": "USAP-DC", "title": "Collaborative research: Redox Balance in Antarctic Notothenioid fishes: Do Icefishes have an Advantage?"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Electronic fishing logs LM Gould 2015", "uid": "600390", "west": null}, {"awards": "1043781 O\u0027Brien, Kristin", "bounds_geometry": null, "date_created": "Tue, 06 Dec 2016 00:00:00 GMT", "description": null, "east": null, "geometry": null, "keywords": "Antarctica; Antarctic Peninsula; Biota; Fish; Sample/collection Description; Sample/Collection Description; Southern Ocean", "locations": "Antarctic Peninsula; Antarctica; Southern Ocean", "north": null, "nsf_funding_programs": null, "persons": "O\u0027Brien, Kristin", "project_titles": "Collaborative research: Redox Balance in Antarctic Notothenioid fishes: Do Icefishes have an Advantage?", "projects": [{"proj_uid": "p0000320", "repository": "USAP-DC", "title": "Collaborative research: Redox Balance in Antarctic Notothenioid fishes: Do Icefishes have an Advantage?"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Redox Balance in Antarctic Notothenioid Fishes", "uid": "600382", "west": null}, {"awards": "0741301 O\u0027Brien, Kristin", "bounds_geometry": ["POLYGON((-64.45 -63.29,-64.249 -63.29,-64.048 -63.29,-63.847 -63.29,-63.646 -63.29,-63.445 -63.29,-63.244 -63.29,-63.043 -63.29,-62.842 -63.29,-62.641 -63.29,-62.44 -63.29,-62.44 -63.371,-62.44 -63.452,-62.44 -63.533,-62.44 -63.614,-62.44 -63.695,-62.44 -63.776,-62.44 -63.857,-62.44 -63.938,-62.44 -64.019,-62.44 -64.1,-62.641 -64.1,-62.842 -64.1,-63.043 -64.1,-63.244 -64.1,-63.445 -64.1,-63.646 -64.1,-63.847 -64.1,-64.048 -64.1,-64.249 -64.1,-64.45 -64.1,-64.45 -64.019,-64.45 -63.938,-64.45 -63.857,-64.45 -63.776,-64.45 -63.695,-64.45 -63.614,-64.45 -63.533,-64.45 -63.452,-64.45 -63.371,-64.45 -63.29))"], "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "Antarctic notothenioid fishes have evolved in the Southern Ocean for 10-14 MY under an unusual set of circumstances. Their characteristics include the complete absence of the circulating oxygen-binding protein, hemoglobin (Hb) within the Channichthyid (Icefish) family of notothenioids. Moreover, some species within the 16 members of this family have also lost the ability to express the oxygen-binding and storage protein, myoglobin (Mb) in cardiac muscle. Our previous work has determined that the loss of Hb and/or Mb is correlated with significant increases in densities of mitochondria within oxidative tissues, and extensive remodeling of these vital organelles. To date, nothing is known about how modifications in mitochondrial architecture of icefishes affect organelle function, or more importantly, how they affect organismal-level physiology. Most critical for Antarctic fishes is that mitochondrial characteristics have been linked to how well ectotherms can withstand increases in temperature. \nThis collaborative research project will address the hypothesis that the unusual mitochondrial architecture of Antarctic Channichthyids has led to changes in function that impact their ability to withstand elevations in temperature. Specifically, the research will (1) determine if the unusual mitochondrial architecture of icefishes affects function and contributes to organismal thermal sensitivity, (2) identify differences in organismal thermal tolerance between red- and white- blooded notothenioids, (3) identify molecular mechanisms regulating changes in mitochondrial structure in icefishes. The results may establish channichthyid icefishes as a sentinel taxon for signaling the impact of global warming on the Southern Ocean. Broad impacts of this project will be realized by participation of high school biology teachers in field work through cooperation with the ARMADA project at the University of Rhode Island, as well as graduate education.\n", "east": -62.44, "geometry": ["POINT(-63.445 -63.695)"], "keywords": "Biota; Oceans; Pot; Southern Ocean; Trawl", "locations": "Southern Ocean", "north": -63.29, "nsf_funding_programs": null, "persons": "O\u0027Brien, Kristin", "project_titles": "Collaborative Research: Linkages among Mitochondrial Form, Function and Thermal Tolerance of Antarctic Notothenioid Fishes", "projects": [{"proj_uid": "p0000483", "repository": "USAP-DC", "title": "Collaborative Research: Linkages among Mitochondrial Form, Function and Thermal Tolerance of Antarctic Notothenioid Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.1, "title": "Linkages among Mitochondrial Form, Function and Thermal Tolerance of Antarctic Notothenioid Fishes", "uid": "600084", "west": -64.45}, {"awards": "0436190 Eastman, Joseph", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "Patterns of biodiversity, as revealed by basic research in organismal biology, may be derived from ecological and evolutionary processes expressed in unique settings, such as Antarctica. The polar regions and their faunas are commanding increased attention as declining species diversity, environmental change, commercial fisheries, and resource management are now being viewed in a global context. Commercial fishing is known to have a direct and pervasive effect on marine biodiversity, and occurs in the Southern Ocean as far south as the Ross Sea. The nature of fish biodiversity in the Antarctic is different than in all other ocean shelf areas. Waters of the Antarctic continental shelf are ice covered for most of the year and water temperatures are nearly constant at -1.5 C. In these waters components of the phyletically derived Antarctic clade of Notothenioids dominate fish diversity. In some regions, including the southwestern Ross Sea, Notothenioids are overwhelmingly dominant in terms of number of species, abundance, and biomass. Such dominance by a single taxonomic group is unique among shelf faunas of the world. In the absence of competition from a taxonomically diverse fauna, Notothenioids underwent a habitat or depth related diversification keyed to the utilization of unfilled niches in the water column, especially pelagic or partially pelagic zooplanktivory and piscivory. This has been accomplished in the absence of a swim bladder for buoyancy control. They also may form a special type of adaptive radiation known as a species flock, which is an assemblage of a disproportionately high number of related species that have evolved rapidly within a defined area where most species are endemic. Diversification in buoyancy is the hallmark of the notothenioid radiation. Buoyancy is the feature of notothenioid biology that determines whether a species lives on the substrate, in the water column or both. Buoyancy also influences other key aspects of life history including swimming, feeding and reproduction and thus has implications for the role of the species in the ecosystem. With similarities to classic evolutionary hot spots, the Antarctic shelf and its Notothenioid radiation merit further exploration. The 2004 \u0027International Collaborative Expedition to collect and study Fish Indigenous to Sub-Antarctic Habitats,\u0027 or, \u0027ICEFISH,\u0027 provided a platform for collection of notothenioid fishes from sub-Antarctic waters between South America and Africa, which will be examined in this project. This study will determine buoyancy for samples of all notothenioid species captured during the ICEFISH cruise. This essential aspect of the biology is known for only 19% of the notothenioid fauna. Also, the gross and microscopic anatomy of brains and sense organs of the phyletically basal families Bovichtidae, Eleginopidae, and of the non-Antarctic species of the primarily Antarctic family Nototheniidae will be examined. The fish biodiversity and endemicity in poorly known localities along the ICEFISH cruise track, seamounts and deep trenches will be quantified. Broader impacts include improved information for comprehending and conserving biodiversity, a scientific and societal priority.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Biota; NBP0404; Oceans; R/v Nathaniel B. Palmer; Southern Ocean", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": null, "persons": "Eastman, Joseph", "project_titles": "Biodiversity, Buoyancy and Morphological Studies of Non-Antarctic Notothenioid Fishes", "projects": [{"proj_uid": "p0000106", "repository": "USAP-DC", "title": "Biodiversity, Buoyancy and Morphological Studies of Non-Antarctic Notothenioid Fishes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Biodiversity, Buoyancy and Morphological Studies of Non-Antarctic Notothenioid Fishes", "uid": "600038", "west": -180.0}, {"awards": "0437887 Sidell, Bruce", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "The polar ocean presently surrounding Antarctica is the coldest, most thermally stable marine environment on earth. Because oxygen solubility in seawater is inversely proportional to temperature, the cold Antarctic seas are an exceptionally oxygen-rich aquatic habitat. Eight families of a single perciform suborder, the Notothenioidei, dominate the present fish fauna surrounding Antarctica. Notothenioids account for approximately 35% of fish species and 90% of fish biomass south of the Antarctic Polar Front. Radiation of closely related notothenioid species thus has occurred rapidly and under a very unusual set of conditions: relative oceanographic isolation from other faunas due to circumpolar currents and deep ocean trenches surrounding the continent, chronically, severely cold water temperatures, very high oxygen availability, very low levels of niche competition in a Southern Ocean depauperate of species subsequent to a dramatic crash in species diversity of fishes that occurred sometime between the mid-Tertiary and present. These features make Antarctic notothenioid fishes an uniquely attractive group for the study of physiological and biochemical adaptations to cold body temperature. Few distinctive features of Antarctic fishes are as unique as the pattern of expression of oxygen-binding proteins in one notothenioid family, the Channichthyidae (Antarctic icefishes). All channichthyid icefishes lack the circulating oxygen-binding protein, hemoglobin (Hb); the intracellular oxygen-binding protein, myoglobin (Mb) is not uniformly expressed in species of this family. Both proteins are normally considered essential for adequate delivery of oxygen to aerobically poised tissues of animals. To compensate for the absence of Hb, icefishes have developed large hearts, rapidly circulate a large blood volume and possess elaborate vasculature of larger lumenal diameter than is seen in red-blooded fishes. Loss of Mb expression in oxidative muscles correlates with dramatic elevation in density of mitochondria within the cell, although each individual organelle is less densely packed with respiratory proteins. Within the framework of oxygen movement, the adaptive significance of greater vascular density and mitochondrial populations is understandable but mechanisms underlying development of these characteristics remain unknown. The answer may lie in another major function of both Hb and Mb, degradation of the ubiquitous bioactive compound, nitric oxide (NO). The research will test the hypothesis that loss of hemoprotein expression in icefishes has resulted in an increase in levels of NO that mediate modification of vascular systems and expansion of mitochondrial populations in oxidative tissues. The objectives of the proposal are to quantify the vascular density of retinas in +Hb and -Hb notothenioid species, to characterize NOS isoforms and catalytic activity in retina and cardiac muscle of Antarctic notothenioid fishes, to evaluate level of expression of downstream factors implicat ed in angiogenesis (in retinal tissue) and mitochondrial biogenesis (in cardiac muscle), and to determine whether inhibition of NOS in vivo results in regression of angiogenic and mitochondrial biogenic responses in icefishes. Broader impacts range from basic biology, through training of young scientists, to enhanced understanding of clinically relevant biomedical processes.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Biota; Oceans; Pot; Sample/collection Description; Sample/Collection Description; Southern Ocean; Trawl", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": null, "persons": "Sidell, Bruce", "project_titles": "Collaborative Research: Differential Expression of Oxygen-binding Proteins in Antarctic Fishes Affects Nitric Oxide-mediated Pathways of Angiogenesis and Mitochondrial Biogenesis.", "projects": [{"proj_uid": "p0000527", "repository": "USAP-DC", "title": "Collaborative Research: Differential Expression of Oxygen-binding Proteins in Antarctic Fishes Affects Nitric Oxide-mediated Pathways of Angiogenesis and Mitochondrial Biogenesis."}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Differential Expression of Oxygen-binding Proteins in Antarctic Fishes Affects Nitric Oxide-mediated Pathways of Angiogenesis and Mitochondrial Biogenesis", "uid": "600039", "west": -180.0}]

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