The effect of long-term adaptation to different levels of salinity on urea synthesis and tissue amino acid concentrations in Rana cancrivora

Balinsky, J.B.; Dicker, S. E.; Elliott, Annie B.

doi:10.1016/0305-0491(72)90203-9

Cited by 13 publications

(8 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Finally, different pathways for the aquatic and terrestrial osmoregulatory physiology may simply, however, dismiss the coupling hypothesis. Most terrestrial amphibians stop voiding urine and overstimulate the synthesis and accumulation of urea as a means of increasing their internal osmolality to cope with osmotic stress (Balinsky et al, 1972;Katz & Hoffman, 1990;Sinsch et al, 1992;Hoffman & Katz, 1997). Unfortunately, the information available on tadpole osmoregulation is scarce.…”

Section: Lack Of Association Between Drought and Salinity Tolerancementioning

confidence: 99%

Adaptation or exaptation? An experimental test of hypotheses on the origin of salinity tolerance inBufo calamita

Gómez-Mestre

Tejedo

2005

J of Evolutionary Biology

View full text Add to dashboard Cite

The natterjack toad (Bufo calamita) shows variation in embryonic and larval salinity tolerance across populations in southern Spain. However, its aquatic/terrestrial biphasic life cycle, together with remarkable differences in salinity tolerance between Spanish and UK freshwater populations suggest an alternative hypothesis to local adaptation. Drought resistance during the terrestrial phase and salinity tolerance during the aquatic phase are both related to osmotic stress tolerance, and if there were an association between them, one could have evolved as an exaptation from the other. To test such an association, we reared B. calamita juveniles from three populations known to differ genetically in their salinity tolerance, under either dry or humid conditions. Drought decreased growth rate, enhanced burying behaviour, and decreased foraging activity and efficiency. No significant population × treatment interaction was found for any variable, i.e. populations were equally affected by drought. These results do not support the hypothesis of a genetic association between salinity and drought tolerance.

show abstract

Section: Lack Of Association Between Drought and Salinity Tolerancementioning

confidence: 99%

Adaptation or exaptation? An experimental test of hypotheses on the origin of salinity tolerance inBufo calamita

Gómez-Mestre

Tejedo

2005

J of Evolutionary Biology

View full text Add to dashboard Cite

show abstract

“…One may presume this is also true of R. cancrivora. Ureogenesis is induced by saline acclimation in the crab-eating frog (Balinski et al 1972). Like the coelacanth and unlike chondrichthians, the crab-eating frog does not reabsorb urea in its renal tubules (Schmidt-Nielsen & Lee 1962), although there may be some urea reabsorption by the urinary bladder.…”

Section: The Crab-eating Frogmentioning

confidence: 99%

Guppies, toadfish, lungfish, coelacanths and frogs: a scenario for the evolution of urea retention in fishes

Griffith

1991

Environ Biol Fish

View full text Add to dashboard Cite

SynopsisThe question of how (and why) the ureosmotic strategy, characteristic of Latimeria chalumnae and the chondrichthians evolved is addressed. There are three requirements for ureosmotic regulation: urea synthesis via the ornithine-urea cycle, urea tolerance involving biochemical and physiological adjustments, and urea retention that requires renal, branchial, metabolic and reproductive adaptations. Several examples of lower vertebrates in which urea plays a physiological role are considered to see whether they might provide insight into the origin of ureosmotic regulation. The guppy shows high urea synthesis and retention during embryonic development, and it is possible that a developmental role of urea is a general phenomenon in fishes. The toadfish, thought to be an enigma with high urea synthesis in the absence of an obvious physiological role of urea, is ureotelic under some conditions. Its urea excretion is likely related to renal function and/or parental care. In lungfish high ureogenesis is associated with estivation in periodically dry habitats. The resultant hyperuremia prevents ammonia toxicity, inhibits water loss and may repress metabolism. Latimeria is a classic marine ureosmotic regulator in which urea is used as an osmolyte that allows osmotic equilibrium with sea water while maintaining low ion levels. Adults of the frog, Rana cancrivora, are also ureosmotic regulators in brackish water. A scenario is proposed that suggests how ureosmotic regulation could have evolved in Latimeria and other fishes. The ornithine-urea cycle (composed of an arginine synthetic pathway and a second pathway that splits arginine into urea) occurred in fossil anadromous agnathans. Here the first pathway functioned in the ammocoete-like larvae for the generation of arginine to supplement a protein-deficient diet of algae, whereas the arginase pathway was important in the embryo for vitellin catabolism. Gnathostome evolution was associated with trends towards large eggs and prolonged development, requiring a complete ornithine-urea cycle for ammonia detoxification in embryos. Retention of a complete ornithine-urea cycle throughout adult life (via paedomorphosis) would preadapt any relatively large, sluggish, euryhaline fish for ureosmotic regulation when it was exposed to sea water. It is suggested that ureosmotic regulators evolved from freshwater or anadromous ancestors that entered the marine habitat. Once early ureosmotic regulators were established in the sea there would have been strong selection for internal fertilization and development, as is seen in Latimeria and many elasmobranchs. It is suggested that ureosmotic regulation was a common strategy in Paleozoic marine gnathostomes.

show abstract

“…They typically inhabit brackish water of mangrove forests, but live happily in freshwater and can be acclimated to 75k seawater (25 ppt or higher; Wright, 2004). Salinity tolerance is not unique to F. cancrivora, because Xenopus laevis and Bufo viridis are also known to withstand 20 and 26 ppt of salinity, respectively (Balinsky, 1972). Nevertheless, F. cancrivora is probably the most tolerant of the known amphibian species (Balinsky, 1972).…”

Section: Introductionmentioning

confidence: 97%

“…Salinity tolerance is not unique to F. cancrivora, because Xenopus laevis and Bufo viridis are also known to withstand 20 and 26 ppt of salinity, respectively (Balinsky, 1972). Nevertheless, F. cancrivora is probably the most tolerant of the known amphibian species (Balinsky, 1972). Wright (2004) considered that the tolerance of this crab-eating frog in part resulted from their rapid accumulation of organic osmolytes, namely urea, and this elevation of urea concentrations in body fluids is most likely due to an acceleration of urea synthesis via the induction of the key OUC enzyme, CPSase I, and possibly other enzymes.…”

Section: Introductionmentioning

confidence: 99%

Complete nucleotide sequence and gene arrangement of the mitochondrial genome of the crab-eating frog Fejervarya cancrivora and evolutionary implications

Ren

Zhu

et al. 2009

Gene

View full text Add to dashboard Cite

The effect of long-term adaptation to different levels of salinity on urea synthesis and tissue amino acid concentrations in Rana cancrivora

Cited by 13 publications

References 14 publications

Adaptation or exaptation? An experimental test of hypotheses on the origin of salinity tolerance inBufo calamita

Adaptation or exaptation? An experimental test of hypotheses on the origin of salinity tolerance inBufo calamita

Guppies, toadfish, lungfish, coelacanths and frogs: a scenario for the evolution of urea retention in fishes

Complete nucleotide sequence and gene arrangement of the mitochondrial genome of the crab-eating frog Fejervarya cancrivora and evolutionary implications

Contact Info

Product

Resources

About