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Permeability to glycerol differs in erythrocytes from freeze‐tolerant Hyla chrysoscelis and freeze‐intolerant Lithobates catesbeianus
Author(s) -
Honer Naava,
Finatti Luiz,
Frisbie James,
Goldstein David
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.937.11
Subject(s) - lithobates , biology , glycerol , bullfrog , hyla , incubation , acclimatization , biophysics , zoology , ecology , biochemistry
Hyla chrysoscelis is a freeze tolerant treefrog that accumulates cryoprotective glycerol during cold acclimation in advance of freezing. In contrast, the bullfrog Lithobates catesbeianus is freeze intolerant and does not accumulate glycerol. We hypothesized that freeze tolerance in Hyla should entail higher cellular permeability to water and glycerol, and that this is facilitated by aqua/glyceroporins. We tested this by assessing permeability, as change in shape, of RBCs from Hyla and Lithobates exposed to water, glycerol, or urea gradients. Timelapse images of RBCs were recorded using MetaMorph software on a Nikon inverted phase contrast microscope, and cell morphology was measured using ImageJ. Initial analyses suggest similar water and urea permeability between species. Both Hyla and Lithobates RBCs react to these stresses with rapid cell shape change from elliptical to spherical, a response blocked by pre‐incubation with 0.3 mM HgCl 2 . Both species also express a protein reactive to antibody against the Hyla glyceroporin HC‐3, which confers significant glycerol permeability. However, whereas Hyla RBCs become spherical upon incubation in glycerol solution, those from Lithobates do not. The results suggest lower permeability to glycerol and/or different characteristics of the cellular cytoskeleton in Lithobates . Supported by NSF IOS‐1121457 to D. Goldstein and C. M. Krane.