Origin and Mechanism of Evolution of Antifreeze Glycoproteins in Polar Fishes
325
antifreezes [48], although it is present in extremely low circulatory
concentrations and thus its physiological role as an antifreeze is dubious.
In any event, like type II AFP, this may represent another case in which
the progenitor molecule could serve as an antifreeze prototype, and thus
holds interest from the standpoint of structure-function relationships. We
have also recently discovered an abundant AFP in an Arctic liparid fish
that superficially resembles type I AFP in having high Ala content but
differs in all other aspects (no sequence repeats and over two times in size)
(unpublished results), and thus likely represents a new antifreeze type with
a distinct genetic origin. The evolution of the diverse fish antifreeze
proteins to achieve the same end function undoubtedly qualifies as one of
the most interesting model systems for studies of macro-adaptation and
molecular evolution. As more advances are made in deciphering the
origins and evolution of these proteins, a wealth of information on
adaptive molecular evolution will certainly be forthcoming.
Acknowledgments
I would like to thank the organizers of the Fishes of the Antarctic Ocean Network
and especially Dr. Guido di Prisco for the invitation to give this presentation at the
fmal conference of the Network. I greatly appreciated the travel information
provided by Dr. Eva Pisano. The European Science Foundation funded my travel
to the conference. I thank Dr. Joe Eastman for all his helpful discussions. This
work was funded by NSF grants OPP 96-15023 to C.-H.c. Cheng and AL.
DeVries and OPP 93-17629 to AL. DeVries.
References
1. K.ennett JP (1982) Marine geology. Prentice-Hall, New Jersey
2. Prosser CL (1973) Water: osmotic balance; hormonal regulation. In: Prosser
CL (ed) Comparative animal physiology. Saunders, Philadelphia, pp 1-78
3. Eastman JT (1993) Antarctic fish biology. Academic Press, California
4. Hubold G (1991) Ecology of notothenioid fish in the Weddell Sea. In: di
Prisco G, Maresca M, Tota (eds) Biology of Antarctic fish. Springer-Verlag,
Berlin, pp 3-22
5. Ekau W (1990) Demersal fish fauna of the Weddell Sea. Antarct Sci. 2:129137
6. Dewitt HH (1971) Coastal and deep-water benthic fishes of the Antarctic. In:
Bushnell VC (ed) Antarctic map folio series folio 15. American
Geographical Society, New York, pp 1-10
7. Cheng C-HC, DeVries AL (1991) The role of antifreeze glycopeptides and
peptides in the freezing avoidance of cold-water fish. In: di Prisco G (ed)
Life under extreme conditions. Springer-Verlag, Berlin-Heidelberg, pp 1-14
325
antifreezes [48], although it is present in extremely low circulatory
concentrations and thus its physiological role as an antifreeze is dubious.
In any event, like type II AFP, this may represent another case in which
the progenitor molecule could serve as an antifreeze prototype, and thus
holds interest from the standpoint of structure-function relationships. We
have also recently discovered an abundant AFP in an Arctic liparid fish
that superficially resembles type I AFP in having high Ala content but
differs in all other aspects (no sequence repeats and over two times in size)
(unpublished results), and thus likely represents a new antifreeze type with
a distinct genetic origin. The evolution of the diverse fish antifreeze
proteins to achieve the same end function undoubtedly qualifies as one of
the most interesting model systems for studies of macro-adaptation and
molecular evolution. As more advances are made in deciphering the
origins and evolution of these proteins, a wealth of information on
adaptive molecular evolution will certainly be forthcoming.
Acknowledgments
I would like to thank the organizers of the Fishes of the Antarctic Ocean Network
and especially Dr. Guido di Prisco for the invitation to give this presentation at the
fmal conference of the Network. I greatly appreciated the travel information
provided by Dr. Eva Pisano. The European Science Foundation funded my travel
to the conference. I thank Dr. Joe Eastman for all his helpful discussions. This
work was funded by NSF grants OPP 96-15023 to C.-H.c. Cheng and AL.
DeVries and OPP 93-17629 to AL. DeVries.
References
1. K.ennett JP (1982) Marine geology. Prentice-Hall, New Jersey
2. Prosser CL (1973) Water: osmotic balance; hormonal regulation. In: Prosser
CL (ed) Comparative animal physiology. Saunders, Philadelphia, pp 1-78
3. Eastman JT (1993) Antarctic fish biology. Academic Press, California
4. Hubold G (1991) Ecology of notothenioid fish in the Weddell Sea. In: di
Prisco G, Maresca M, Tota (eds) Biology of Antarctic fish. Springer-Verlag,
Berlin, pp 3-22
5. Ekau W (1990) Demersal fish fauna of the Weddell Sea. Antarct Sci. 2:129137
6. Dewitt HH (1971) Coastal and deep-water benthic fishes of the Antarctic. In:
Bushnell VC (ed) Antarctic map folio series folio 15. American
Geographical Society, New York, pp 1-10
7. Cheng C-HC, DeVries AL (1991) The role of antifreeze glycopeptides and
peptides in the freezing avoidance of cold-water fish. In: di Prisco G (ed)
Life under extreme conditions. Springer-Verlag, Berlin-Heidelberg, pp 1-14