Do Antarctic Fish Respond to Heat Shock?
Luisella CarratU', Andrew Y. Gracel, Stefania Buono', and Bruno
Maresca'
'International Institute of Genetics and Biophysics, CNR, Via Marconi 12, 80125
Napoli, Italy
2University of Livetpool, Department of Environmental and Evolutionary
Biology, Livetpool L69 3BX, UK
Introduction
Temperature is a major environmental factor requiring adaptive responses
and it is a central selective element in speciation. One of the best known
and complex mechanisms that is primarily involved in protecting cells
from various forms of stresses, such as temperature, is the stress (heat
shock) response [1]. For poikilotherms, fluctuations in environmental
temperatures can be fatal. Sudden drops in temperature can lead to a
reduction in membrane fluid state that, in tum, causes cessation of normal
functions. Unless rapidly corrected, such alterations will lead to
physiological damage and, ultimately, to death. Several essential cellular
activities depend on proper membrane functionality [2]. For elevated
environmental temperatures, some of the problems encountered during
chilling are also relevant. There still exist the dual needs of being able to
"sense" the elevated environmental temperature and to couple this
detection to the induction of gene expression - such as for heat shock
genes. Recently, there have been several lines of evidence which suggest
that changes in response to an abrupt rise in the environmental temperature
may have analogies with chilling adaptation. Thus, membrane lipid
composition, as well as the dynamic state of membrane lipids, represent
the basic elements for membrane functionality. Membranes, indeed, have
multiple physical properties which permit the cell to sense environmental
changes. Several recent studies from our and other laboratories now
indicate that an immediate change in temperature causes a reorganization
of membrane components [3,4]. In addition, abrupt changes occurring in
the environment during pathological states or during the aging process can
cause modifications in membrane structure, membrane protein activity,
signal transduction and gene expression with consequent loss of
physiological functions [5,6]. Recently, it has been shown that some forms
of heat injury are due to the reorganization of lipid protein complexes of
the membrane at the time of heat shock [7,8]. It has also been shown that a
G. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer-Verlag Italia 1998
Luisella CarratU', Andrew Y. Gracel, Stefania Buono', and Bruno
Maresca'
'International Institute of Genetics and Biophysics, CNR, Via Marconi 12, 80125
Napoli, Italy
2University of Livetpool, Department of Environmental and Evolutionary
Biology, Livetpool L69 3BX, UK
Introduction
Temperature is a major environmental factor requiring adaptive responses
and it is a central selective element in speciation. One of the best known
and complex mechanisms that is primarily involved in protecting cells
from various forms of stresses, such as temperature, is the stress (heat
shock) response [1]. For poikilotherms, fluctuations in environmental
temperatures can be fatal. Sudden drops in temperature can lead to a
reduction in membrane fluid state that, in tum, causes cessation of normal
functions. Unless rapidly corrected, such alterations will lead to
physiological damage and, ultimately, to death. Several essential cellular
activities depend on proper membrane functionality [2]. For elevated
environmental temperatures, some of the problems encountered during
chilling are also relevant. There still exist the dual needs of being able to
"sense" the elevated environmental temperature and to couple this
detection to the induction of gene expression - such as for heat shock
genes. Recently, there have been several lines of evidence which suggest
that changes in response to an abrupt rise in the environmental temperature
may have analogies with chilling adaptation. Thus, membrane lipid
composition, as well as the dynamic state of membrane lipids, represent
the basic elements for membrane functionality. Membranes, indeed, have
multiple physical properties which permit the cell to sense environmental
changes. Several recent studies from our and other laboratories now
indicate that an immediate change in temperature causes a reorganization
of membrane components [3,4]. In addition, abrupt changes occurring in
the environment during pathological states or during the aging process can
cause modifications in membrane structure, membrane protein activity,
signal transduction and gene expression with consequent loss of
physiological functions [5,6]. Recently, it has been shown that some forms
of heat injury are due to the reorganization of lipid protein complexes of
the membrane at the time of heat shock [7,8]. It has also been shown that a
G. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer-Verlag Italia 1998