Biochemical Genetics, Vol. 15, Nos. 7/8, 1977
Isoenzyme Status and Genetic Variability of Serum Esterases in the Lesser Snow Goose, Anser caerulescens caerulescens Thaddeus A. Bargiello, ~'2 Joseph Grossfield, 2 R. W. Steele, 1 and Fred Cooke 1
Received 27 Oct. 1976--Final 25 Jan. 1977
A maximum of 22 bands comprising four esterase subgroups--acetylesterase, carboxylesterase, cholinesterase, and acetylcholinesterase--were detected following electrophoresis of lesser snow goose sera on polyacrylamide gels. A minimum of seven structural genes was surmised to be involved in the biosynthesis of these enzymes following physiochemical characterizations. The genetic variability of these loci was calculated to be 1.25°/oo average heterozygosity, while 14.3% of the loci were polymorphic. These estimates of genetic variability were substantially lower than those reported for other vertebrate species. The low degree of genetic variabilityfound in snow goose serum esterases coupled with the extensive protein multiplicity observed may possibly reflect an adaptive strategy based on " b i o c h e m i c a l p l a s t i c i t y " rather than genie heterozygosity for this species. The nature of evolutionary forces ac¢ing upon multiple enzyme systems such as esterases is discussed. The concept of " c o n d i t i o n a l n e u t r a l i t y " is introduced and defined within this context. KEY WORDS: isoenzyme status ; electrophoretic genetic variability; snow goose; esterases.
INTRODUCTION V e r t e b r a t e carboxylic ester hydrolases, E.C. s u b g r o u p 3.1.1., have long been k n o w n to exhibit extensive p r o t e i n multiplicity following electrophoresis (Augustinsson, 1959a,b,c). The isoenzyme status and genetic basis o f several This research was carried out under grants from the National Research Council of Canada and the Canadian Wildlife Service to F. Cooke. J. Grossfield was supported by grants from the Nationa! Institutes of Health, GM 21630 and FRAP 10576. Department of Biology, Queen's University, Kingston, Ontario, Canada. 2 Department of Biology, The City College of New York, New York, New York. 741 © 1977 Plenum Publishing Corp., 227 West 17th Street, New York, N.Y. 10011. To promote freer access to published material in the spirit o f the 1976 Copyright Law, Plenum sells reprint articles from all its journals. This availability underlines the fact that no part o f this publication may be reproduced, stored in a retrieval
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Isoenzyme Status and Genetic Variability of Serum Esterases in the Lesser Snow Goose, Anser caerulescens caerulescens Thaddeus A. Bargiello, ~'2 Joseph Grossfield, 2 R. W. Steele, 1 and Fred Cooke 1
Received 27 Oct. 1976--Final 25 Jan. 1977
A maximum of 22 bands comprising four esterase subgroups--acetylesterase, carboxylesterase, cholinesterase, and acetylcholinesterase--were detected following electrophoresis of lesser snow goose sera on polyacrylamide gels. A minimum of seven structural genes was surmised to be involved in the biosynthesis of these enzymes following physiochemical characterizations. The genetic variability of these loci was calculated to be 1.25°/oo average heterozygosity, while 14.3% of the loci were polymorphic. These estimates of genetic variability were substantially lower than those reported for other vertebrate species. The low degree of genetic variabilityfound in snow goose serum esterases coupled with the extensive protein multiplicity observed may possibly reflect an adaptive strategy based on " b i o c h e m i c a l p l a s t i c i t y " rather than genie heterozygosity for this species. The nature of evolutionary forces ac¢ing upon multiple enzyme systems such as esterases is discussed. The concept of " c o n d i t i o n a l n e u t r a l i t y " is introduced and defined within this context. KEY WORDS: isoenzyme status ; electrophoretic genetic variability; snow goose; esterases.
INTRODUCTION V e r t e b r a t e carboxylic ester hydrolases, E.C. s u b g r o u p 3.1.1., have long been k n o w n to exhibit extensive p r o t e i n multiplicity following electrophoresis (Augustinsson, 1959a,b,c). The isoenzyme status and genetic basis o f several This research was carried out under grants from the National Research Council of Canada and the Canadian Wildlife Service to F. Cooke. J. Grossfield was supported by grants from the Nationa! Institutes of Health, GM 21630 and FRAP 10576. Department of Biology, Queen's University, Kingston, Ontario, Canada. 2 Department of Biology, The City College of New York, New York, New York. 741 © 1977 Plenum Publishing Corp., 227 West 17th Street, New York, N.Y. 10011. To promote freer access to published material in the spirit o f the 1976 Copyright Law, Plenum sells reprint articles from all its journals. This availability underlines the fact that no part o f this publication may be reproduced, stored in a retrieval
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