Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-25T18:30:47.639Z Has data issue: false hasContentIssue false
  • English
  • Français

Enzyme variability in the Drosophila willistoni Group. V. Genic variation in natural populations of Drosophila equinoxialis*

Published online by Cambridge University Press:  14 April 2009

Francisco J. Ayala ,
Jeffrey R. Powell  and
Martin L. Tracey
Francisco J. Ayala
Affiliation:
Department of Genetics, University of California, Davis, California 95616
Jeffrey R. Powell
Affiliation:
Department of Genetics, University of California, Davis, California 95616
Martin L. Tracey
Affiliation:
Department of Genetics, University of California, Davis, California 95616
Rights & Permissions [Opens in a new window]

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We have studied genetic variation at 27 loci in 42 samples from natural populations of a neotropical species, Drosophila equinoxialis, using standard techniques of starch-gel electrophoresis to detect allelic variation in genes coding for enzymes. There is considerarle genetic variability in D. equinoxialis. We have found allelic variation in each of the 27 loci, although not in every population. On the average, 71% of the loci are polymorphic – that is, the most common allele has a frequency no greater than 0·95 – in a given population. An individual is heterozygous on the average at 21·8% of its loci.

The amount of genetic variation fluctuates widely from locus to locus. At the Mdh-2 locus arout 1% of the individuals are heterozygotes; at the other extreme more than 56% of the individuals are heterozygous at the Est-3. At any given locus the configuration of allelic frequencies is strikingly similar from locality to locality. At each and every locus the same allele is generally the most common throughout the distribution of the species. Yet differences in gene frequencies occur between localities. The pattern of genetic variation is incompatible with the hypothesis that the variation is adaptively neutral. Genetic variation in D. equinoxialis is maintained by balancing natural selection.

The amount and pattern of genetic variation is similar in D. equinoxialis and its sibling species, D. willistoni. Yet the two species are genetically very different. Different sets of alleles occur at nearly 40% of the loci.

Type
Research Article
Information
Genetics Research , Volume 20 , Issue 1 , August 1972 , pp. 19 - 42
Copyright
Copyright © Cambridge University Press 1972

References

REFERENCES

Ayala, F. J. (1972). Darwinian versus non-Darwinian evolution in natural populations of Drosophila. Proceedings of the Sixth Berkeley Symposium on Mathematical Statistics and Probability.CrossRefGoogle Scholar
Ayala, F. J., Mourão, C. A., Pérez-Salas, S., Richmond, R. & Dobzhansky, Th. (1970). Enzyme variability in the Drosophilla willistoni group. I. Genetic differentiation among sibling species. Proceedings of the National Academy of Sciences, U.S.A. 67, 225–232.CrossRefGoogle Scholar
Ayala, F. J. & Powell, J. R. (1972). Allozymes as diagnostic characters of sibling species of Drosophila. Proceedings of the National Academy of Sciences, U.S.A. 69, 1094–1096.CrossRefGoogle ScholarPubMed
Ayala, F. J., Powell, J. R. & Dobzhansky, Th. (1971). Enzyme variability in the Drosophila willistoni group. II. Polymorphisms in continental and island populations of Drosophila willistoni. Proceedings of the National Academy of Sciences, U.S.A. 68, 2480–2483.CrossRefGoogle Scholar
Ayala, F. J., Powell, J. R., Tracey, M. L., Mourão, C. A. & Pérez-Salas, S. (1972). Enzyme variability in the Drosophila willistoni group. IV. Genetic variation in natural populations of Drosophila willistoni. Genetics 70, 113–139.CrossRefGoogle ScholarPubMed
Cunha, A. B. Da, Burla, H. & Dobzhansky, Th. (1950). Adaptive chromosomal polymorphism in Drosophila willistoni. Evolution 4, 212–235.CrossRefGoogle Scholar
Cunha, A. B. Da & Dobzhansky, Th. (1954). A further study of chromosomal polymorphism in Drosophila willistoni and its relation to the environment. Evolution 8, 119–134.CrossRefGoogle Scholar
Cunha, A. B. Da, Dobzhansky, Th., Pavlovsky, O. & Spassky, B. (1959). Genetics of natural populations. XXVTII. Supplementary data on the chromosomal polymorphism in Drosophila willistoni in relation to its environment. Evolution 13, 389–404.CrossRefGoogle Scholar
Dobzhansky, Th. (1957). Genetics of natural populations. XXVI. Chromosomal variability in island and continental populations of Drosophila willistoni from Central America and the West Indies. Evolution 11, 280–293.CrossRefGoogle Scholar
Fisher, R. A. (1930). The Genetical Theory of Natural Selection. Oxford: Clarendon Press.CrossRefGoogle Scholar
Gillespie, J. H. & Kojima, K. (1968). The degree of polymorphisms in enzymes involved in energy production compared to that in non-specific enzymes in two Drosophila ananassae populations. Proceedings of the National Academy of Sciences, U.S.A. 61, 582–585.CrossRefGoogle Scholar
Huang, S. L., Singh, M. & Kojima, K. (1971). A study of frequency-dependent selection observed in the Esterase-6 locus of Drosophila melanogaster using a conditioned media method. Genetics 68, 97–104.CrossRefGoogle ScholarPubMed
Kimura, M. (1968). Genetic variability maintained in a finite population due to mutational production of neutral and nearly neutral isoalleles. Genetical Research 11, 247–269.CrossRefGoogle Scholar
Kimura, M. & Crow, J. F. (1964). The number of alleles that can be maintained in a finite population. Genetics 49, 725–738.CrossRefGoogle Scholar
Kimura, M. & Ohta, T. (1971). Protein polymorphism as a phase of molecular evolution Nature 229, 467–469.CrossRefGoogle ScholarPubMed
King, J. L. & Jukes, T. H. (1969). Non-Darwinian evolution. Science, N.Y. 164, 788–798.CrossRefGoogle ScholarPubMed
Kojima, K., Gillespie, J. & Tobari, Y. N. (1970). A profile of Drosophila species' enzymes assayed by electrophoresis. I. Number of alleles, heterozygosites, and linkage disequilibrium in glucose-metarolizing systems and some other enzymes. Biochemical Genetics 4, 627–637.CrossRefGoogle Scholar
Lewontin, R. C. & Hubby, J. L. (1966). A molecular approach to the study of genic heterozygosity in natural populations. II. Amounts of variation and degree of heterozygosity in natural populations of Drosophila pseudoobscura. Genetics 54, 595–609.CrossRefGoogle Scholar
Mross, G. A. & Doolittle, R. F. (1967). Amino acid sequence studies on artiodactyl fibrinopeptides. II. Vicuna, elk, pronghorn, antelope and water buffalo. Archives of Biochemistry and Biophysics 122, 674–684.CrossRefGoogle Scholar
O'Brien, S. J. & MacIntyre, R. J. (1969). An analysis of gene-enzyme variability in natural populations of Drosophila melanogaster and D. simulans. American Naturalist 103, 97–113.CrossRefGoogle Scholar
Powell, J. R. (1971). Genetic polymorphisms in varied environments. Science 174, 1035–1036.CrossRefGoogle ScholarPubMed
Prakash, S. (1969). Genic variation in a natural population of Drosophila persimilis. Proceedings of the National Academy of Sciences, U.S.A. 62, 778–784.CrossRefGoogle Scholar
Prakash, S., Lewontin, R. C. & Hubby, J. L. (1969). A molecular approach to the study of genic heterozygosity in natural populations. IV. Patterns of genic variation in central, marginal, and isolated populations of Drosophila pseudoobscura. Genetics 61, 841–858.CrossRefGoogle Scholar
Richmond, R. C. (1972). Enzyme variability in the Drosophila willistoni group. III. Amounts of variability in the superspecies, D. paulistorum. Genetics 70, 87–112.CrossRefGoogle Scholar
Richmond, R. C. & Powell, J. R. (1970). Evidence of heterosis associated with an enzyme locus in a natural population of Drosophila. Proceedings of the National Academy of Sciences, U.S.A. 67, 1264–1267.CrossRefGoogle Scholar
Spassky, B., Richmond, R. C., Pérez-Salas, S., Pavlovsky, O., Mourão, C. A., Hunter, A. S., Hoenigsberg, H., Dobzhansky, Th. & Ayala, F. J. (1971). Geography of the sibling species related to Drosophila willistoni, and of the semispecies of the Drosophila paulistorum complex. Evolution 25, 129–143.Google ScholarPubMed
Wills, C. & Nichols, L. (1971). Single gene heterosis in Drosophila revealed by inbreeding. Nature 233, 123–125.CrossRefGoogle ScholarPubMed