Thermal profiles reveal stark contrasts in properties of biological membranes from heart among Antarctic notothenioid fishes which vary in expression of hemoglobin and myoglobin ...

• Main Authors: Evans, Elizabeth R., Farnoud, Amir M., O'Brien, Kristin M., Crockett, Elizabeth L.
• Format: Dataset
• Language: English
• Published: Dryad 2021
• Subjects: Antarctic; Palmer Station; Palmer-Station; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.5061/dryad.qbzkh18gd; https://datadryad.org/stash/dataset/doi:10.5061/dryad.qbzkh18gd

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 °C) to 20 °C. Compositions of membrane phospholipids and cholesterol contents were also quantified. Membranes from all four species of icefishes exhibited greater fluidity than membranes from the ... : Animals were captured near Palmer Station, Antarctica. Tissues were collected on site and flash frozen for further analysis. Membranes were prepared from ventricular tissue and analyzed by GC-MS to determine membrane phospholipid distribution (Lipids). Fluoresecence depolarization of native membranes was quantified over a temperature range to determine membrane fluidity (Fluidity). Integrity of liposomes generated from prepared membranes were quantified over a temperature range to determine membrane leakage by fluorescent spectrophotometry (Leak). Lipid and fluidity data are raw. Leakage data has been normalized to maximal liposomal leakage at each respective temperature point. ...