Osmolyte Adjustments as a Pressure Adaptation in Deep-Sea Chondrichthyan Fishes: An Intraspecific Test in Arctic Skates (Amblyraja hyperborea) along a Depth Gradient

  title={Osmolyte Adjustments as a Pressure Adaptation in Deep-Sea Chondrichthyan Fishes: An Intraspecific Test in Arctic Skates (Amblyraja hyperborea) along a Depth Gradient},
  author={Paul H Yancey and Ben Speers-Roesch and Sheila Atchinson and James D. Reist and Andrew R. Majewski and Jason R. Treberg},
  journal={Physiological and Biochemical Zoology},
  pages={788 - 796}
Accumulation of trimethylamine N-oxide (TMAO) by deep-sea animals is proposed to protect proteins against the destabilizing effects of high hydrostatic pressure (the piezolyte hypothesis). Chondrichthyan fishes (sharks, rays, and chimaeras) provide a unique test of this hypothesis because shallow-living species have elevated TMAO levels to counteract the destabilizing effects of high urea levels accumulated for osmoregulation. Limited interspecific studies of chondrichthyans reveal that… 

Cellular responses in marine animals to hydrostatic pressure.

  • P. Yancey
  • Biology, Environmental Science
    Journal of experimental zoology. Part A, Ecological and integrative physiology
  • 2020
For permanent deep-sea species, CSR/CHR mechanisms have not been directly tested, but evidence in Mariana Trench amphipods and snailfish suggest that HSP and desaturase genes, and possibly piezolyte synthesis, have undergone habitat-related selection.

Unique osmoregulatory morphology in primitive sharks: an intermediate state between holocephalan and derived shark secretory morphology.

The morphological similarities between the lobulate rectal-gland anatomy of primitive sharks and the secretory morphology of holocephalans may represent an intermediate state between Holocephali and derived shark species.

An osmolality/ salinity-responsive enhancer 1 (OSRE1) in intron 1 promotes salinity induction of tilapia glutamine synthetase

It is shown that hyperosmotic induction of glutamine synthetase represents a prominent part of this switch between hyper- and hypo-osmoregulation in Euryhaline tilapia, and that proper intron 1 positioning and the presence of an OSRE1 in introns 1 are required for precise enhancement of hyperosMotic glutamine Synthetase expression.

Deep-sea sharks: Relation between the liver's buoyancy and red aerobic muscle volumes, a new approach.

Trimethylamine N-Oxide (TMAO) and Trimethylamine (TMA) Determinations of Two Hadal Amphipods

This study supports the important role of TMAO for the environmental adaptability of hadal amphipods and speculates on the molecular evolution and protein structure of FMO3 in hadal species.

Dynamical Model for the Counteracting Effects of Trimethylamine N-Oxide on Urea in Aqueous Solutions under Pressure.

A dynamical model in terms of hydrogen-bond lifetimes is developed for the hydrogen bonding propensities of cosolutes and water in an aqueous solution to proteins and provides an explanation for both the counteracting effects of TMAO on urea denaturation and the depth-dependent urea:TMAO ratio found in cartilaginous fish.

How Do Urea and Trimethylamine N-Oxide Influence the Dehydration-Induced Phase Transition of a Lipid Membrane?

This study suggests that urea significantly inhibits the dehydration-induced fluid-to-gel phase transition by strongly interacting with the lipid membrane via hydrogen bonds, which balances the reduced lipid hydration due to the decreasing water content.

Exploring the influence of natural cosolvents on the free energy and conformational landscape of filamentous actin and microtubules.

The effects of various types of natural cosolvents, such as urea and the osmolyte trimethylamine-N-oxide (TMAO), on the temperature- and pressure-dependent stability of their polymeric states, F-actin and microtubules are explored.

Chronic, low-dose TMAO treatment reduces diastolic dysfunction and heart fibrosis in hypertensive rats.

Evidence is provided that a moderate increase in plasma TMAO does not have a negative effect on the circulatory system and seems to reduce diastolic dysfunction in pressure-overloaded hearts in rats.



Does the physiology of chondrichthyan fishes constrain their distribution in the deep sea?

ABSTRACT The deep sea is the largest ecosystem on Earth but organisms living there must contend with high pressure, low temperature, darkness and scarce food. Chondrichthyan fishes (sharks and their

Decreasing Urea∶Trimethylamine N-Oxide Ratios with Depth in Chondrichthyes: A Physiological Depth Limit?

The deepest chondrichthyans may be unable to accumulate sufficient TMAO to counteract pressure; however, deeper-living specimens are needed to fully test this hypothesis.

Trimethylamine oxide, betaine and other osmolytes in deep-sea animals: depth trends and effects on enzymes under hydrostatic pressure.

TMAO and, to a lesser extent, betaine are generally better stabilizers than other common osmolytes (myo-inositol, taurine and glycine), in terms of counteracting the effects of pressure on NADH Km of grenadier lactate dehydrogenase and ADP KM of anemone and rabbit pyruvate kinase.

Trimethylamine oxide counteracts effects of hydrostatic pressure on proteins of deep-sea teleosts.

It was shown that, for lactate dehydrogenases (LDH), 250 mM TMAO fully offset an increase in NADH K(m) at physiological pressure, and partly reversed pressure-enhanced losses of activity at supranormal pressures, and support the hypothesis that this protein stabilizer counteracts inhibition of proteins by hydrostatic pressure.


Trimethylamine oxide (TMAO) as an osmolyte typically occurs at 20–70 mM in shallow-water marine teleost fishes. However, it has not been previously examined in deep-living species. We collected

Correlation of Trimethylamine Oxide and Habitat Depth within and among Species of Teleost Fish: An Analysis of Causation

The data strongly support the hypothesis that TMAO is adaptively regulated with depth in deep‐sea teleosts, and no clear link between TmaO and lipid was found.

Marine fish may be biochemically constrained from inhabiting the deepest ocean depths

By capturing the world's second-deepest known fish, the hadal snailfish Notoliparis kermadecensis from 7,000 m, it is found that they have the highest recorded TMAO contents, which yield an extrapolated maximum for fish at about 8,200 m, previously unidentified evidence that biochemistry may constrain depth for a large taxonomic group.

High contents of trimethylamine oxide correlating with depth in deep-sea teleost fishes, skates, and decapod crustaceans.

High TMAO contents in muscles of other animals collected off the coast of Oregon may reflect diet, reduce osmoregulatory costs, increase buoyancy, or counteract destabilization of proteins by pressure.

Solute accumulation in the deep-sea bacterium Photobacterium profundum

The β-HB molecules represent a novel class of osmolytes, termed 'piezolytes,' whose cellular levels responded to hydrostatic pressure as well as osmotic pressure, since the organic solutes increased with increasing external NaCl in the medium.

Trimethylamine oxide stabilizes teleost and mammalian lactate dehydrogenases against inactivation by hydrostatic pressure and trypsinolysis.

For all the species and pressures tested, 250 mmol l(-)(1) TMAO reduced trypsinolysis significantly, and for all except S. altivelis, which was minimally affected by 101.3 MPa pressure, T MAO stabilized the LDH homologs and reduced pressure denaturation significantly.