High genetic variability of esterase loci in natural populations of Parus major, P. caeruleus, and P. ater.
In Parus major, P. caeruleus, and P. ater the genetic variation of 16 isozyme loci was determined. The focus was on esterases that show high phenotypic variation in natural populations of these species. The degree of heterozygosity of the "non-esterase" loci was 0.029 +/- 0.008 (P. major); 0.023 +/- 0.012 (P. caeruleus), and 0.034 +/- 0.034 (P. ater). Including the esterase loci with up to six alleles per locus the overall degree of heterozygosity increased to 0.130 +/- 0.056 (P. major); 0.143 +/- 0.067 (P. caeruleus), and 0.194 +/- 0.090 (P. ater). We explain the high level of variability of esterases by gene amplification and subsequent selection for high allelic heterogeneity. Substrate specificity of loci is assumed to allow for multiple resistance against various toxic components. Large allelic valiation of esterases, therefore, increases the fitness of Parus species and allows for utilizing new food resources.
Driesel
Simon
S
Division of General Human Genetics, Institute of Anthropology and Human Genetics, University of Tübingen, Wilhelmstrasse 27, D-72074 Tübingen, Germany.
Bachmann
Lutz
L
Stauss
Michael
M
Segelbacher
Gernot
G
Flach
Doris
D
Tomiuk
Jürgen
J
Kömpf
Jost
J
D000483:Alleles; D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D004950:Esterases / Q000235:genetics*; D005784:Gene Amplification; D014644:Genetic Variation; D005828:Genetics, Population; D005858:Germany; D006579:Heterozygote; D007525:Isoelectric Focusing; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D011110:Polymorphism, Genetic; D012189:Retrospective Studies; D012641:Selection, Genetic; D020308:Songbirds / Q000235:genetics*; D013045:Species Specificity; D013379:Substrate Specificity
D007527:Isoenzymes; D004950:Esterases