Molecular Adaptations of Antarctic Fish Hemoglobins
Guido di Prisco
Institute of Protein Biochemistry and Enzymology, CNR, Via Marconi 12, 80125
Naples, Italy
Introduction
Following the inception in 1985 of the Italian National Programme for
Antarctic Research and the consequent development of our studies on the
structure and function of hemoglobin (Hb) [1-5], we have now reached a
stage in which we are finally able to begin identifying firm guidelines for
understanding the interplay among biochemical/physiological processes of
oxygen transport, ecology and adaptive evolution.
For the study of temperature adaptations, Antarctica - more than any
other habitat on earth - is indeed a unique natural laboratory. Oxygen
carriers are one of the most interesting systems for studying the
interrelationships between environmental conditions and molecular
evolution. Hb, being a direct link between the exterior and body
requirements and fulfilling its primary function under extremely variable
conditions, has experienced a major evolutionary pressure to adapt and
modify its functional features. In view of the role of temperature in
modifying the oxygenation-deoxygenation cycle in respiring tissues,
thermodynamic analysis deserves special attention.
Fishes of the perciform suborder Notothenioidei, mostly confined within
Antarctic and subAntarctic waters, are the dominant component of the
Southern Ocean fauna. They comprise 95 of the 174 benthic species of the
continental shelf and upper continental slope, and 120 (including nonAntarctic notothenioids) of the 274 Southern Ocean species described to
date [6]. Notothenioids probably appeared in the early Tertiary [7]; they
began to diversify while gradually adapting to progressive cooling and
isolation.
Bovichtidae, Nototheniidae (with the highest number of species, 34
Antarctic and 15 nonAntarctic), Harpagiferidae, Artedidraconidae,
Bathydraconidae and Channichthyidae are the families of the suborder.
Notothenioids are red-blooded, except Channichthyidae, the only known
vertebrates whose blood - in the adult stage - is devoid ofHb [8].
This report summarizes the advances in the study of molecular
adaptations in Antarctic fish hemoglobins. Thermodynamic analysis, X-ray
G. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer-Verlag Italia 1998
Guido di Prisco
Institute of Protein Biochemistry and Enzymology, CNR, Via Marconi 12, 80125
Naples, Italy
Introduction
Following the inception in 1985 of the Italian National Programme for
Antarctic Research and the consequent development of our studies on the
structure and function of hemoglobin (Hb) [1-5], we have now reached a
stage in which we are finally able to begin identifying firm guidelines for
understanding the interplay among biochemical/physiological processes of
oxygen transport, ecology and adaptive evolution.
For the study of temperature adaptations, Antarctica - more than any
other habitat on earth - is indeed a unique natural laboratory. Oxygen
carriers are one of the most interesting systems for studying the
interrelationships between environmental conditions and molecular
evolution. Hb, being a direct link between the exterior and body
requirements and fulfilling its primary function under extremely variable
conditions, has experienced a major evolutionary pressure to adapt and
modify its functional features. In view of the role of temperature in
modifying the oxygenation-deoxygenation cycle in respiring tissues,
thermodynamic analysis deserves special attention.
Fishes of the perciform suborder Notothenioidei, mostly confined within
Antarctic and subAntarctic waters, are the dominant component of the
Southern Ocean fauna. They comprise 95 of the 174 benthic species of the
continental shelf and upper continental slope, and 120 (including nonAntarctic notothenioids) of the 274 Southern Ocean species described to
date [6]. Notothenioids probably appeared in the early Tertiary [7]; they
began to diversify while gradually adapting to progressive cooling and
isolation.
Bovichtidae, Nototheniidae (with the highest number of species, 34
Antarctic and 15 nonAntarctic), Harpagiferidae, Artedidraconidae,
Bathydraconidae and Channichthyidae are the families of the suborder.
Notothenioids are red-blooded, except Channichthyidae, the only known
vertebrates whose blood - in the adult stage - is devoid ofHb [8].
This report summarizes the advances in the study of molecular
adaptations in Antarctic fish hemoglobins. Thermodynamic analysis, X-ray
G. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer-Verlag Italia 1998