Abstract
Evidence of strong association of alleles at the Esterase-5 and adult Acid phosphatase-6 loci with the Sex Ratio and the Standard X chromosome arrangements in D. pseudoobscura is presented. There is no differentiation at these two loci, either in the Sex Ratio or the Standard arrangement from two widely separated geographic populations. At the Esterase-5 locus, alleles characteristic of one arrangement are found in low frequencies in the other arrangement. It is concluded, from these and other observations that the differentiation between the Sex Ratio and the Standard arrangement, at these two loci, is a result of natural selection favoring different coadapted gene blocks in these arrangements. The average heterozygosity at these two loci in different karyotypes is in the following order: ST/SR > ST/ST >> SR/SR which agrees very well with the fitness estimates of these karyotypes.
Full Text
The Full Text of this article is available as a PDF (373.9 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Prakash S., Lewontin R. C., Hubby J. L. 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. 1969 Apr;61(4):841–858. doi: 10.1093/genetics/61.4.841. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sturtevant A H, Dobzhansky T. Geographical Distribution and Cytology of "Sex Ratio" in Drosophila Pseudoobscura and Related Species. Genetics. 1936 Jul;21(4):473–490. doi: 10.1093/genetics/21.4.473. [DOI] [PMC free article] [PubMed] [Google Scholar]