Multi-Faceted Role of Autophagy In Freeze Tolerant Wood Frog

Cryobiology ◽  
2021 ◽  
Vol 103 ◽  
pp. 177-178
Author(s):  
Gurjit Singh ◽  
Rasha al-attar ◽  
Kenneth B. Storey
Keyword(s):  
Wood Frog ◽  
Freeze Tolerant

Freeze-thaw injury in erythrocytes of the freeze-tolerant wood frog, Rana sylvatica

1991 ◽  
Vol 261 (6) ◽  
pp. R1346-R1350 ◽  
Author(s):  
J. P. Costanzo ◽  
R. E. Lee
Keyword(s):  
Cell Injury ◽  
Osmotic Fragility ◽  
Rana Sylvatica ◽  
Freeze Tolerance ◽  
Wood Frog ◽  
In Vitro Tests ◽  
Freezing And Thawing ◽  
Freeze Tolerant ◽  
High Concentrations

Erythrocytes from the freeze-tolerant wood frog (Rana sylvatica) were subjected to in vitro tests of freeze tolerance, cryoprotection, and osmotic fragility. The responses of cells from frogs acclimated to 4 or 15 degrees C were similar. Erythrocytes that were frozen in saline hemolyzed at -4 degrees C or lower. The addition of high concentrations (150 and 1,500 mM) of glucose or glycerol, cryoprotectants produced naturally by freeze-tolerant frogs, significantly reduced cell injury at -8 degrees C, but concentrations of 1.5 or 15 mM were ineffective. Hemolysis was reduced by 94% with 1,500 mM glycerol and by 84% with 1,500 mM glucose; thus glycerol was the more effective cryoprotectant. Mean fragility values for frog erythrocytes incubated in hypertonic and hypotonic saline were 1,938 and 49 mosM, respectively. Survival in freeze tolerance and cryoprotection experiments was comparable for erythrocytes from frogs and humans, suggesting that these cells may respond similarly to freezing-related stresses. However, the breadth of osmotic tolerance, standardized for differences in isotonicity, was greater for frog erythrocytes than for human erythrocytes. Our data suggest that erythrocytes from R. sylvatica are adequately protected by glucose under natural conditions of freezing and thawing.

Enzymatic regulation of seasonal glycogen cycling in the freeze-tolerant wood frog, Rana sylvatica

2016 ◽  
Vol 186 (8) ◽  
pp. 1045-1058 ◽  
Author(s):  
M. Clara F. do Amaral ◽  
Richard E. Lee ◽  
Jon P. Costanzo
Keyword(s):  
Rana Sylvatica ◽  
Wood Frog ◽  
Enzymatic Regulation ◽  
Freeze Tolerant

Regulation of pyruvate kinase from muscle of Freeze tolerant wood frog, Rana sylvatica

Cryobiology ◽  
2016 ◽  
Vol 73 (3) ◽  
pp. 437
Author(s):  
J. Mattice ◽  
M. Smolinski ◽  
K. Storey
Keyword(s):  
Pyruvate Kinase ◽  
Rana Sylvatica ◽  
Wood Frog ◽  
Freeze Tolerant

Osmotic and freezing tolerance in spermatozoa of freeze-tolerant and -intolerant frogs

1998 ◽  
Vol 275 (3) ◽  
pp. R713-R719 ◽  
Author(s):  
Jon P. Costanzo ◽  
John A. Mugnano ◽  
Heidi M. Wehrheim ◽  
Richard E. Lee
Keyword(s):  
Plasma Membrane ◽  
Rana Sylvatica ◽  
Wood Frog ◽  
Leopard Frog ◽  
Subzero Temperatures ◽  
In Vitro Exposure ◽  
Freeze Tolerant ◽  
Motility Rate ◽  
Winter Breeding

The wood frog ( Rana sylvatica) is a freeze-tolerant species that encounters subzero temperatures during its winter breeding season, whereas the leopard frog ( R. pipiens) is freeze intolerant and breeds in spring. Osmotic and freezing tolerances of spermatozoa from these species were inferred from spermolysis rate, integrity of the plasma membrane as judged using vital dye assay, and motility rate. Sperm of R. sylvatica became motile in hypotonic media (≤220 mosmol/kg) and tolerated in vitro exposure to osmotic concentrations spanning nearly three orders of magnitude. Relative to sperm from R. sylvatica, which were unaffected by freezing at temperatures of −4°C or greater, R. pipiens sperm were more susceptible to osmotic damage and cryoinjury. These differences likely reflect cellular adaptations to somatic freezing in R. sylvatica. Unprotected sperm from both species were extensively damaged by freezing at −8°C, but the presence of glucose, the cryoprotectant used by R. sylvatica, or the permeant glycerol markedly diminished cryoinjury. These data suggest the feasibility of developing gamete cryopreservation protocols to aid efforts in conserving amphibian populations.

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