Abstract
I propose a new estimator for jointly estimating two-gene and four-gene coefficients of relatedness between individuals from an outbreeding population with data on codominant genetic markers and compare it, by Monte Carlo simulations, to previous ones in precision and accuracy for different distributions of population allele frequencies, numbers of alleles per locus, actual relationships, sample sizes, and proportions of relatives included in samples. In contrast to several previous estimators, the new estimator is well behaved and applies to any number of alleles per locus and any allele frequency distribution. The estimates for two- and four-gene coefficients of relatedness from the new estimator are unbiased irrespective of the sample size and have sampling variances decreasing consistently with an increasing number of alleles per locus to the minimum asymptotic values determined by the variation in identity-by-descent among loci per se, regardless of the actual relationship. The new estimator is also robust for small sample sizes and for unknown relatives being included in samples for estimating allele frequencies. Compared to previous estimators, the new one is generally advantageous, especially for highly polymorphic loci and/or small sample sizes.
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Selected References
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- Li C. C., Weeks D. E., Chakravarti A. Similarity of DNA fingerprints due to chance and relatedness. Hum Hered. 1993 Jan-Feb;43(1):45–52. doi: 10.1159/000154113. [DOI] [PubMed] [Google Scholar]
- Lynch M. Estimation of relatedness by DNA fingerprinting. Mol Biol Evol. 1988 Sep;5(5):584–599. doi: 10.1093/oxfordjournals.molbev.a040518. [DOI] [PubMed] [Google Scholar]
- Lynch M., Ritland K. Estimation of pairwise relatedness with molecular markers. Genetics. 1999 Aug;152(4):1753–1766. doi: 10.1093/genetics/152.4.1753. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marshall T. C., Slate J., Kruuk L. E., Pemberton J. M. Statistical confidence for likelihood-based paternity inference in natural populations. Mol Ecol. 1998 May;7(5):639–655. doi: 10.1046/j.1365-294x.1998.00374.x. [DOI] [PubMed] [Google Scholar]
- Ritland K. Marker-inferred relatedness as a tool for detecting heritability in nature. Mol Ecol. 2000 Sep;9(9):1195–1204. doi: 10.1046/j.1365-294x.2000.00971.x. [DOI] [PubMed] [Google Scholar]
- Thomas S. C., Hill W. G. Estimating quantitative genetic parameters using sibships reconstructed from marker data. Genetics. 2000 Aug;155(4):1961–1972. doi: 10.1093/genetics/155.4.1961. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Thompson E. A. A restriction on the space of genetic relationships. Ann Hum Genet. 1976 Nov;40(2):201–204. doi: 10.1111/j.1469-1809.1976.tb00181.x. [DOI] [PubMed] [Google Scholar]
- Thompson E. A. The estimation of pairwise relationships. Ann Hum Genet. 1975 Oct;39(2):173–188. doi: 10.1111/j.1469-1809.1975.tb00120.x. [DOI] [PubMed] [Google Scholar]
- Van de Casteele T., Galbusera P., Matthysen E. A comparison of microsatellite-based pairwise relatedness estimators. Mol Ecol. 2001 Jun;10(6):1539–1549. doi: 10.1046/j.1365-294x.2001.01288.x. [DOI] [PubMed] [Google Scholar]