Skip to main content
PMC home page
Genetics logoLink to Genetics
. 1996 Jul;143(3):1369–1381. doi: 10.1093/genetics/143.3.1369

Demographic Genetics of Brown Trout (Salmo Trutta) and Estimation of Effective Population Size from Temporal Change of Allele Frequencies

P E Jorde 1, N Ryman 1
PMCID: PMC1207405  PMID: 8807308

Abstract

We studied temporal allele frequency shifts over 15 years and estimated the genetically effective size of four natural populations of brown trout (Salmo trutta L.) on the basis of the variation at 14 polymorphic allozyme loci. The allele frequency differences between consecutive cohorts were significant in all four populations. There were no indications of natural selection, and we conclude that random genetic drift is the most likely cause of temporal allele frequency shifts at the loci examined. Effective population sizes were estimated from observed allele frequency shifts among cohorts, taking into consideration the demographic characteristics of each population. The estimated effective sizes of the four populations range from 52 to 480 individuals, and we conclude that the effective size of natural brown trout populations may differ considerably among lakes that are similar in size and other apparent characteristics. In spite of their different effective sizes all four populations have similar levels of genetic variation (average heterozygosity) indicating that excessive loss of genetic variability has been retarded, most likely because of gene flow among neighboring populations.

Full Text

The Full Text of this article is available as a PDF (3.3 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Allendorf F. W., Mitchell N., Ryman N., Ståhl G. Isozyme loci in brown trout (Salmo trutta L.): detection and interpretation from population data. Hereditas. 1977;86(2):179–190. doi: 10.1111/j.1601-5223.1977.tb01228.x. [DOI] [PubMed] [Google Scholar]
  2. Caballero A. Developments in the prediction of effective population size. Heredity (Edinb) 1994 Dec;73(Pt 6):657–679. doi: 10.1038/hdy.1994.174. [DOI] [PubMed] [Google Scholar]
  3. Caballero A., Hill W. G. Effective size of nonrandom mating populations. Genetics. 1992 Apr;130(4):909–916. doi: 10.1093/genetics/130.4.909. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Felsenstein J. Inbreeding and variance effective numbers in populations with overlapping generations. Genetics. 1971 Aug;68(4):581–597. doi: 10.1093/genetics/68.4.581. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Guyomard R., Krieg F. Electrophoretic variation in six populations of brown trout (Salmo trutta L.). Can J Genet Cytol. 1983 Aug;25(4):403–413. doi: 10.1139/g83-062. [DOI] [PubMed] [Google Scholar]
  6. Jorde P. E., Ryman N. Allele frequency estimation at loci with incomplete co-dominant expression. Heredity (Edinb) 1990 Dec;65(Pt 3):429–433. doi: 10.1038/hdy.1990.114. [DOI] [PubMed] [Google Scholar]
  7. Jorde P. E., Ryman N. Temporal allele frequency change and estimation of effective size in populations with overlapping generations. Genetics. 1995 Feb;139(2):1077–1090. doi: 10.1093/genetics/139.2.1077. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Lewontin R. C., Krakauer J. Distribution of gene frequency as a test of the theory of the selective neutrality of polymorphisms. Genetics. 1973 May;74(1):175–195. doi: 10.1093/genetics/74.1.175. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Nei M. Analysis of gene diversity in subdivided populations. Proc Natl Acad Sci U S A. 1973 Dec;70(12):3321–3323. doi: 10.1073/pnas.70.12.3321. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Nei M., Tajima F. Genetic drift and estimation of effective population size. Genetics. 1981 Jul;98(3):625–640. doi: 10.1093/genetics/98.3.625. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Ryman N., Allendorf F. W., Ståhl G. Reproductive isolation with little genetic divergence in sympatric populations of brown trout (Salmo trutta). Genetics. 1979 May;92(1):247–262. doi: 10.1093/genetics/92.1.247. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Sugg D. W., Chesser R. K. Effective population sizes with multiple paternity. Genetics. 1994 Aug;137(4):1147–1155. doi: 10.1093/genetics/137.4.1147. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Tajima F., Nei M. Note on genetic drift and estimation of effective population size. Genetics. 1984 Mar;106(3):569–574. doi: 10.1093/genetics/106.3.569. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Wang J. Exact inbreeding coefficient and effective size of finite populations under partial sib mating. Genetics. 1995 May;140(1):357–363. doi: 10.1093/genetics/140.1.357. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Waples R. S. A generalized approach for estimating effective population size from temporal changes in allele frequency. Genetics. 1989 Feb;121(2):379–391. doi: 10.1093/genetics/121.2.379. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Wright S, Dobzhansky T, Hovanitz W. Genetics of Natural Populations. VII. the Allelism of Lethals in the Third Chromosome of Drosophila Pseudoobscura. Genetics. 1942 Jul;27(4):363–394. doi: 10.1093/genetics/27.4.363. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Genetics are provided here courtesy of Oxford University Press

RESOURCES