Physiological and Genetic Responses to Environmental Stress
187
pesticide, and a petroleum compound (Downs et al., 2001a). Other biomarker systems have been developed for species as diverse as cordgrass, estuarine fish, tadpoles,
heat-stressed corals (Downs et al., 2000), and grass shrimp (Downs et al., 2001b).
Representative stressors already used include elevated temperature, pesticides, heavy
metals, and a pathogenic bacterium. Such a system could be extremely useful to
measure the health status of marine turtle populations. Because turtles have nucleated
red blood cells, a molecular biomarker system could theoretically be developed for
diagnosis using blood samples relatively quickly, easily, and inexpensively.
A system for molecular diagnosis of stress might include biomarkers of general
cellular integrity and oxidative stress (i.e., ubiquitin or malondialdehyde), HSPs such
as hsp60 and hsp70, antioxidant enzymes (superoxide dismutases), enzymes that
respond to pH stress (acid and alkaline phosphatases and dehydrogenases), and
members of the P450 family (markers of xenochemical exposure). The synthesis of
HSPs at normal physiological and at elevated temperatures, for example, has been
correlated with the natural adaptation of nine lizard species to heat, in that animals
adapted to desert conditions showed higher constitutive levels of hsp70 than lizards
that inhabited cooler climates (Ulmasov et al., 1992). Lizards adapted to cooler
climates also have a lower thermal threshold for HSP expression when exposed to
heat shock than desert-adapted animals (Zatsepina et al., 2000). It has been suggested
that increases in hsp70 mRNA levels in blood may serve as an early indicator of
temperature stress in fish (Currie et al., 2000). The genetic response to stress in sea
turtles is (naturally!) unknown, although changes in hsp70 and hsp60 have been
detected in anoxic freshwater turtles (H. Prentice, personal communication).
REFERENCES
Ackerman, R.A., The respiratory gas exchange of sea turtle nests (Chelonia, Caretta), Respir.
Physiol., 31, 19–38, 1977.
Ackerman, R.A., The nest environment and the embryonic development of sea turtles, in:
Lutz, P. and Musick, J. (eds.), The Biology of Sea Turtles, CRC Press, Boca Raton,
FL, 1997, 432 pp.
Adams, S.M. and Ryon, M.G., A comparison of health assessment approaches for evaluating
the effects of contaminant-related stress on fish populations, J. Aquat. Ecosys. Health,
3, 15–25, 1994.
Adams, S.M. et al., Relationships between physiological and fish population responses in a
contaminated stream, Environ. Toxicol. Chem., 11, 1549–1557, 1992.
Ader, R. and Cohen, N., Psychoneuroimmunology: conditioning and stress, Ann. Rev. Psychol., 44, 53–85, 1993.
Adnyana, W., Ladds, P.W., and Blair, D., Observations of fibropapillomatosis in green turtles
(Chelonia mydas) in Indonesia, Aust. Vet. J., 75(10), 736–742, 1997.
Aguirre, A.A. and Balazs, G.H., Plasma biochemistry values of green turtles (Chelonia mydas)
with and without fibropapillomas in the Hawaiian Islands, Comp. Hematol. Int., 10(3),
132–137, 2000.
Aguirre, A.A. and Lutz, P.L., Marine turtles as sentinels of ecosystem health: is fibropapillomatosis an indicator?, Ecosys. Health, in press.
1123 book.book Page 187 Monday, November 11, 2002 11:11 AM
187
pesticide, and a petroleum compound (Downs et al., 2001a). Other biomarker systems have been developed for species as diverse as cordgrass, estuarine fish, tadpoles,
heat-stressed corals (Downs et al., 2000), and grass shrimp (Downs et al., 2001b).
Representative stressors already used include elevated temperature, pesticides, heavy
metals, and a pathogenic bacterium. Such a system could be extremely useful to
measure the health status of marine turtle populations. Because turtles have nucleated
red blood cells, a molecular biomarker system could theoretically be developed for
diagnosis using blood samples relatively quickly, easily, and inexpensively.
A system for molecular diagnosis of stress might include biomarkers of general
cellular integrity and oxidative stress (i.e., ubiquitin or malondialdehyde), HSPs such
as hsp60 and hsp70, antioxidant enzymes (superoxide dismutases), enzymes that
respond to pH stress (acid and alkaline phosphatases and dehydrogenases), and
members of the P450 family (markers of xenochemical exposure). The synthesis of
HSPs at normal physiological and at elevated temperatures, for example, has been
correlated with the natural adaptation of nine lizard species to heat, in that animals
adapted to desert conditions showed higher constitutive levels of hsp70 than lizards
that inhabited cooler climates (Ulmasov et al., 1992). Lizards adapted to cooler
climates also have a lower thermal threshold for HSP expression when exposed to
heat shock than desert-adapted animals (Zatsepina et al., 2000). It has been suggested
that increases in hsp70 mRNA levels in blood may serve as an early indicator of
temperature stress in fish (Currie et al., 2000). The genetic response to stress in sea
turtles is (naturally!) unknown, although changes in hsp70 and hsp60 have been
detected in anoxic freshwater turtles (H. Prentice, personal communication).
REFERENCES
Ackerman, R.A., The respiratory gas exchange of sea turtle nests (Chelonia, Caretta), Respir.
Physiol., 31, 19–38, 1977.
Ackerman, R.A., The nest environment and the embryonic development of sea turtles, in:
Lutz, P. and Musick, J. (eds.), The Biology of Sea Turtles, CRC Press, Boca Raton,
FL, 1997, 432 pp.
Adams, S.M. and Ryon, M.G., A comparison of health assessment approaches for evaluating
the effects of contaminant-related stress on fish populations, J. Aquat. Ecosys. Health,
3, 15–25, 1994.
Adams, S.M. et al., Relationships between physiological and fish population responses in a
contaminated stream, Environ. Toxicol. Chem., 11, 1549–1557, 1992.
Ader, R. and Cohen, N., Psychoneuroimmunology: conditioning and stress, Ann. Rev. Psychol., 44, 53–85, 1993.
Adnyana, W., Ladds, P.W., and Blair, D., Observations of fibropapillomatosis in green turtles
(Chelonia mydas) in Indonesia, Aust. Vet. J., 75(10), 736–742, 1997.
Aguirre, A.A. and Balazs, G.H., Plasma biochemistry values of green turtles (Chelonia mydas)
with and without fibropapillomas in the Hawaiian Islands, Comp. Hematol. Int., 10(3),
132–137, 2000.
Aguirre, A.A. and Lutz, P.L., Marine turtles as sentinels of ecosystem health: is fibropapillomatosis an indicator?, Ecosys. Health, in press.
1123 book.book Page 187 Monday, November 11, 2002 11:11 AM