Abstract
The genetic variation and genetic load due to virility, the male reproductive component of fitness, was measured in Drosophila melanogaster and D. pseudoobscura using males homozygous and heterozygous for the second chromosome of each species. Virility was determined in a female-choice, male mating competition experiment where both mating propensity and fertility were taken into account.—The mean virility of the homozygous D. melanogaster males relative to the heterozygous males was 0.50; the relative mean virility of the quasinormal homozygotes was 0.56. The mean virility of the homozygous D. pseudoobscura males relative to the heterozygous males was 0.70; the relative mean virility of the nonsterile homozygotes was 0.72, and of the quasinormal homozygotes, 0.68.—Depending on the species and chromosome sampled, fertile homozygous males had a mean virility 15 to 50% lower than the mean viability of individuals homozygous for a chromosome with quasinormal viability. The genetic load due to virility was also greater than that due to the female reproductive component. This higher level of hidden genetic variation (or genetic load) indicates that the results of Prout (1971a, b) and Bundgaard and Christiansen (1972), where the virility component of fitness dominated the dynamics of an artificial polymorphism, may be more general and that virility may dominate the dynamics of natural polymorphisms as well.
Full Text
The Full Text of this article is available as a PDF (735.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Anderson W. W., Levine L., Olvera O., Powell J. R., de la Rosa M. E., Salceda V. M., Gaso M. I., Guzmán J. Evidence for selection by male mating success in natural populations of Drosophila pseudoobscura. Proc Natl Acad Sci U S A. 1979 Mar;76(3):1519–1523. doi: 10.1073/pnas.76.3.1519. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bundgaard J., Christiansen F. B. Dynamics of polymorphisms. I. Selection components in an experimental population of Drosophila melanogaster. Genetics. 1972 Jul;71(3):439–460. doi: 10.1093/genetics/71.3.439. [DOI] [PubMed] [Google Scholar]
- DOBZHANSKY T., SPASSKY B., TIDWELL T. Genetics of natural populations. 32. Inbreeding and the mutational and balanced genetic loads in natural populations of Drosophila pseudoobscura. Genetics. 1963 Mar;48:361–373. doi: 10.1093/genetics/48.3.361. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dobzhansky T, Holz A M, Spassky B. Genetics of Natural Populations. VIII. Concealed Variability in the Second and the Fourth Chromosomes of Drosophila Pseudoobscura and Its Bearing on the Problem of Heterosis. Genetics. 1942 Sep;27(5):463–490. doi: 10.1093/genetics/27.5.463. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sved J. A. An estimate of heterosis in Drosophila melanogaster. Genet Res. 1971 Aug;18(1):97–105. doi: 10.1017/s0016672300012453. [DOI] [PubMed] [Google Scholar]
- Sved J. A., Ayala F. J. A population cage test for heterosis in Drosophila pseudoobscura. Genetics. 1970 Sep;66(1):97–113. doi: 10.1093/genetics/66.1.97. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Temin R. G. Homozygous viability and fertility loads in Drosophila melanogaster. Genetics. 1966 Jan;53(1):27–46. doi: 10.1093/genetics/53.1.27. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tracey M. L., Ayala F. J. Genetic load in natural populations: is it compatible with the hypothesis that many polymorphisms are maintained by natural selection? Genetics. 1974 Jul;77(3):569–589. doi: 10.1093/genetics/77.3.569. [DOI] [PMC free article] [PubMed] [Google Scholar]