ArticlePloS one2015
Cryoprotectants and extreme freeze tolerance in a subarctic population of the wood frog.
Article in PloS one, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 25 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
25 citing papers in PubMed, 78 citations in OpenAlex.
- Partial Freezing Enables Functional Preservation of Kidney Grafts for up to 10 Days.Research square · 2026Article
- AmphiTherm: a comprehensive database of amphibian thermal tolerance and preference.Scientific data · 2025Article
- Article
- Constitutive Differences in Immune Gene Expression Are Correlated With Wood Frog Populations From Contrasting Winter Environments.Molecular ecology · 2025Article
- Advanced sperm preservation techniques in yellow spotted mountain newts Neurergus derjugini enhance genetic management and conservation efforts.Scientific reports · 2025Article
- Beyond the icebox: modern strategies in organ preservation for transplantation.Clinical transplantation and research · 2024Review
- Effects of hibernation on two important contractile tissues in tibetan frogs, Nanorana parkeri: a perspective from transcriptomics and metabolomics approaches.BMC genomics · 2024Article
- Dynamic evolution of the mTHF gene family associated with primary metabolism across life.BMC genomics · 2024Article
- Proline pre-conditioning of Jurkat cells improves recovery after cryopreservation.RSC medicinal chemistry · 2023Article
- Article
- Freeze tolerance and the underlying metabolite responses in the Xizang plateau frog, Nanorana parkeri.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2021Article
- Purification of carbamoyl phosphate synthetase 1 (CPS1) from wood frog (Rana sylvatica) liver and its regulation in response to ice-nucleation and subsequent whole-body freezing.Molecular and cellular biochemistry · 2019Article
- Overwintering adaptations and extreme freeze tolerance in a subarctic population of the wood frog, Rana sylvatica.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2019Review
- Nitric oxide metabolites in hypoxia, freezing, and hibernation of the wood frog, Rana sylvatica.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2018Article
- Advances in machine perfusion, organ preservation, and cryobiology: potential impact on vascularized composite allotransplantation.Current opinion in organ transplantation · 2018Review
- The cryoprotectant system of Cope's gray treefrog, Dryophytes chrysoscelis: responses to cold acclimation, freezing, and thawing.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2018Article
- Urea and plasma ice-nucleating proteins promoted the modest freeze tolerance in Pleske's high altitude frog Nanorana pleskei.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2018Article
- Urea hydrolysis by gut bacteria in a hibernating frog: evidence for urea-nitrogen recycling in Amphibia.Proceedings. Biological sciences · 2018Article
- Daily thermal fluctuations to a range of subzero temperatures enhance cold hardiness of winter-acclimated turtles.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2017Article
- Article
Corrections and comments
- Erratum issued
Authors and funding
5 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Wood frogs (Rana sylvatica) exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 μmol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 μmol ml-1 (mean ± SEM) in frogs that remained fully hydrated, and to 186.9 ± 12.4 μmol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s) that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to -8°C, either directly or following three cycles of freezing/thawing between -4 and 0°C, or -16°C increased the liver's synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle) or two-thirds (liver) of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea) to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.