Abstract
An approach to increase the resolution power of interval mapping of quantitative trait (QT) loci is proposed, based on analysis of correlated trait complexes. For a given set of QTs, the broad sense heritability attributed to a QT locus (QTL) (say, A/ a) is an increasing function of the number of traits. Thus, for some traits x and y, H(xy)(2) (A/ a) >/= H(x)(2) (A/ a). The last inequality holds even if y does not depend on A/ a at all, but x and y are correlated within the groups AA, Aa and aa due to nongenetic factors and segregation of genes from other chromosomes. A simple relationship connects H(2) (both in single trait and two-trait analysis) with the expected LOD value, ELOD = -1/2N log(1 - H(2)). Thus, situations could exist that from the inequality H(xy)(2) (A/ a) >/= H(x)(2) (A/ a) a higher resolution is provided by the two-trait analysis as compared to the single-trait analysis, in spite of the increased number of parameters. Employing LOD-score procedure to simulated backcross data, we showed that the resolution power of the QTL mapping model can be elevated if correlation between QTs is taken into account. The method allows us to test numerous biologically important hypotheses concerning manifold effects of genomic segments on the defined trait complex (means, variances and correlations).
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Selected References
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- Boehnke M., Moll P. P. Identifying pedigrees segregating at a major locus for a quantitative trait: an efficient strategy for linkage analysis. Am J Hum Genet. 1989 Feb;44(2):216–224. [PMC free article] [PubMed] [Google Scholar]
- Carey G., Williamson J. Linkage analysis of quantitative traits: increased power by using selected samples. Am J Hum Genet. 1991 Oct;49(4):786–796. [PMC free article] [PubMed] [Google Scholar]
- Demenais F., Lathrop G. M., Lalouel J. M. Detection of linkage between a quantitative trait and a marker locus by the lod score method: sample size and sampling considerations. Ann Hum Genet. 1988 Jul;52(Pt 3):237–246. doi: 10.1111/j.1469-1809.1988.tb01101.x. [DOI] [PubMed] [Google Scholar]
- Doebley J., Stec A. Inheritance of the morphological differences between maize and teosinte: comparison of results for two F2 populations. Genetics. 1993 Jun;134(2):559–570. doi: 10.1093/genetics/134.2.559. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jansen R. C., Stam P. High resolution of quantitative traits into multiple loci via interval mapping. Genetics. 1994 Apr;136(4):1447–1455. doi: 10.1093/genetics/136.4.1447. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Korol' A. B., Preigel' I. A., Bocharnikova N. I. Stseplenie mezhdu lokusami kolichestvennykh priznakov i markernymi lokusami. Soobshchenie V. Sovmestnyi analiz neskol'kikh markernykh i kolichestvennykh priznakov. Genetika. 1987 Aug;23(8):1421–1431. [PubMed] [Google Scholar]
- Lande R., Thompson R. Efficiency of marker-assisted selection in the improvement of quantitative traits. Genetics. 1990 Mar;124(3):743–756. doi: 10.1093/genetics/124.3.743. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Weller J. I., Kashi Y., Soller M. Power of daughter and granddaughter designs for determining linkage between marker loci and quantitative trait loci in dairy cattle. J Dairy Sci. 1990 Sep;73(9):2525–2537. doi: 10.3168/jds.S0022-0302(90)78938-2. [DOI] [PubMed] [Google Scholar]