Efficiency of direct selection on quantitative trait loci for a two-trait breeding objective

Koning, G.; Weller, J. I.

doi:10.1007/bf01253969

Cited by 21 publications

(11 citation statements)

References 25 publications

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“…On présente un modèle déterministe de prédiction de la réponse à la sélection massale quand un gène majeur est en ségrégation. Le [8,11,12,16] [2,13,17,18,20]. However, Gibson [6] At each generation (assumed to be discrete), the proportion of selected parents of sex x (x = m, f ) is 7 r x .…”

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Response to mass selection when an identified major gene is segregating

Pong‐Wong¹,

Woolliams²

1998

Genet. Sel. Evol.

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Response to mass selection when an identified major gene is segregating

Pong‐Wong¹,

Woolliams²

1998

Genet. Sel. Evol.

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“…Thus genetic gain with trait-based selection did not surpass MAS over the long-term as noted by Gibson (1994). The 'Gibson effect' was also not detected by de Koning and Weller (1994) in a series of long-term MAS simulations. The gain of 0.15 by MAS at year 10 represents an increase of nearly 20% over the traditional scheme.…”

Section: Resultsmentioning

confidence: 67%

Incorporation of genotype effects into animal model evaluations when only a small fraction of the population has been genotyped

Baruch

Weller

2009

Animal

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The method of Israel and Weller (Estimation of candidate gene effects in dairy cattle populations. Journal of Dairy Science 1998Science , 81, 1653Science -1662 to estimate quantitative trait locus (QTL) effects when only a small fraction of the population was genotyped was investigated by simulation. The QTL effect was underestimated in all cases, but bias was greater for extreme allelic frequencies, and increased with the number of generations included in the simulations. Apparently, as the fraction of animals with inferred genotypes increases, the genotype probabilities tend to 'mimic' the effect of relationships. Unbiased estimates of QTL effects were derived by a modified 'cow model' without the inclusion of the relationship matrix on simulated data, even though only a small fraction of the population was genotyped. This method yielded empirically unbiased estimates for the effects of the genes DGAT1 and ABCG2 on milk production traits in the Israeli Holstein population. Based on these results, an efficient algorithm for marker-assisted selection in dairy cattle was proposed. Quantitative trait loci effects are estimated and subtracted from the cows' records. Genetic evaluations are then computed for the adjusted records. Animals are then selected based on the sum of their polygenic genetic evaluations and QTL effects. This scheme differs from a traditional dairy cattle breeding scheme in that all bull calves were considered candidates for selection. At year 10, total genetic gain was 20% greater by the proposed algorithm as compared to the selection based on a standard animal model for a locus with a substitution effect of 0.5 phenotypic standard deviations. The proposed method is easy to apply, and all required software are 'on the shelf.' It is only necessary to genotype breeding males, which are a very small fraction of the entire population. The method is flexible with respect to the model used for routine genetic evaluation. Any number of genetic markers can be easily incorporated into the algorithm, and the reduction in genetic gain due to incorrect QTL determination is minimal.

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“…Selection directly on QTLs has been investigated previously by de Koning & Weller (1994) but in a different situation (two-traits index selection, pleiotropic QTLs, disassortative mating). Here, selection directly on QTLs is used as an idealized situation to investigate the effect of marker-QTL distance on MBRS efficiency (i.e.…”

Section: (Vi) Effects Of Marker-qtl Distancementioning

confidence: 99%

Efficient marker-based recurrent selection for multiple quantitative trait loci

Goldringer

Openshaw

2000

Genet. Res.

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We studied the efficiency of recurrent selection based solely on marker genotypes (marker-based selection), in order to increase favourable allele frequency at 50 previously detected quantitative trait loci (QTLs). Two selection procedures were investigated, using computer simulations: (1) Truncation Selection (MTS), in which individuals are ranked based on marker score, and best individuals are selected for recombination; and (2) QTL Complementation Selection (QCS), in which individuals are selected such that their QTL composition complements those individuals already selected. Provided QTL locations are accurate, marker-based selection with a population size of 200 was very effective in rapidly increasing frequencies of favourable QTL alleles. QCS methods were more effective than MTS for improving the mean frequency and fixation of favourable QTL alleles. Marker-based selection was not very sensitive to a reduction in population size, and appears valuable to optimize the use of molecular markers in recurrent selection programmes.

show abstract

Efficiency of direct selection on quantitative trait loci for a two-trait breeding objective

Cited by 21 publications

References 25 publications

Response to mass selection when an identified major gene is segregating

Response to mass selection when an identified major gene is segregating

Incorporation of genotype effects into animal model evaluations when only a small fraction of the population has been genotyped

Efficient marker-based recurrent selection for multiple quantitative trait loci

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