Lack of geographic variation in anonymous nuclear polymorphisms in the American oyster, Crassostrea virginica.
Comparing geographic variation of noncoding nuclear DNA polymorphisms, which presumably are neutral to natural selection, with geographic variation of allozymes is potentially a good way to detect the effects of selection on allozyme polymorphisms. A previous study of four anonymous nuclear markers in the American oyster, Crassostrea virginica, found dramatic differences in allele frequency between the Gulf of Mexico and the Atlantic Ocean. In contrast, 14 allozyme polymorphisms were fairly uniform in frequency between the two areas. This led to the conclusion that all of the allozyme polymorphisms were kept uniform in frequency by balancing selection. To test the robustness of this pattern, six additional anonymous nuclear DNA polymorphisms were surveyed in oysters from Panacea, Fla, and Charleston, S.C. on the Gulf and Atlantic coasts, respectively. Unlike the previously studied DNA markers, the six DNA polymorphisms examined here show geographic variation that is not significantly greater than that of allozymes. The reason for the discrepancy between the two sets of DNA polymorphisms is unclear.
McDonald
J H
JH
Department of Biology, University of Delaware, Newark 19716, USA. mcdonald@udel.edu
Verrelli
B C
BC
Geyer
L B
LB
D000483:Alleles; D000569:Americas; D000818:Animals; D002467:Cell Nucleus / Q000235:genetics; D017931:DNA Primers; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D004586:Electrophoresis; D005787:Gene Frequency; D014644:Genetic Variation; D005828:Genetics, Population; D008957:Models, Genetic; D010125:Ostreidae / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D015183:Restriction Mapping
D017931:DNA Primers; D015252:Deoxyribonucleases, Type II Site-Specific; C032229:GANTC-specific type II deoxyribonucleases