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GENETIC HETEROGENEITY WITHIN ELECTROPHORETIC "ALLELES" OF XANTHINE DEHYDROGENASE IN <i>DROSOPHILA PSEUDOOBSCURA</i>

GeneticsPublished 29 November 1976Open access
Rama S. Singh, Richard C Lewontin, A A Felton
Citations215
SJR quartileQ1
SJR score2.27
SNIP1.33
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TL;DR

An experimental plan for an exhaustive determination of genic variation at structural gene loci is presented and shows previously unsuspected population differences between the main part of the species distribution and the isolated population of Bogotá population.

Abstract

An experimental plan for an exhaustive determination of genic variation at structural gene loci is presented. In the initial steps of this program, 146 isochromosomal lines from 12 geographic populations of D. pseudoobscura were examined for allelic variation of xanthine dehydrogenase by the serial use of 4 different electrophoretic conditions and a head stability test. The 5 criteria revealed a total of 37 allelic classes out of the 146 genomes examined where only 6 had been previously revealed by the usual method of gel electrophoresis. This immense increase in genic variation also showed previously unsuspected population differences between the main part of the species distribution and the isolated population of Bogotá population. The average heterozygosity at the Xdh locus is at least 72% in natural populations. This result, together with the very large number of alleles segregating and the pattern of allelic frequencies, has implications for theories of genetic polymorphism which are discussed.

Keywords

Agricultural and Biological SciencesBiochemistry, Genetics and Molecular BiologyEnvironmental Science