scholarly journals Estimation of Variance of Prediction Error for Best Linear Unbiased Prediction Models with Relationships Included

1985 ◽  
Vol 68 (4) ◽  
pp. 930-938 ◽  
Author(s):  
J.I. Weller ◽  
H.D. Norman ◽  
G.R. Wiggans
Genetics ◽  
2020 ◽  
Vol 216 (1) ◽  
pp. 27-41
Author(s):  
Simon Rio ◽  
Laurence Moreau ◽  
Alain Charcosset ◽  
Tristan Mary-Huard

Populations structured into genetic groups may display group-specific linkage disequilibrium, mutations, and/or interactions between quantitative trait loci and the genetic background. These factors lead to heterogeneous marker effects affecting the efficiency of genomic prediction, especially for admixed individuals. Such individuals have a genome that is a mosaic of chromosome blocks from different origins, and may be of interest to combine favorable group-specific characteristics. We developed two genomic prediction models adapted to the prediction of admixed individuals in presence of heterogeneous marker effects: multigroup admixed genomic best linear unbiased prediction random individual (MAGBLUP-RI), modeling the ancestry of alleles; and multigroup admixed genomic best linear unbiased prediction random allele effect (MAGBLUP-RAE), modeling group-specific distributions of allele effects. MAGBLUP-RI can estimate the segregation variance generated by admixture while MAGBLUP-RAE can disentangle the variability that is due to main allele effects from the variability that is due to group-specific deviation allele effects. Both models were evaluated for their genomic prediction accuracy using a maize panel including lines from the Dent and Flint groups, along with admixed individuals. Based on simulated traits, both models proved their efficiency to improve genomic prediction accuracy compared to standard GBLUP models. For real traits, a clear gain was observed at low marker densities whereas it became limited at high marker densities. The interest of including admixed individuals in multigroup training sets was confirmed using simulated traits, but was variable using real traits. Both MAGBLUP models and admixed individuals are of interest whenever group-specific SNP allele effects exist.


Biotecnia ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 136-146
Author(s):  
Osval A. Montesinos-López ◽  
Emeterio Franco-Pérez ◽  
Francisco J. Luna-Vázquez ◽  
Josafat Salinas-Ruiz ◽  
Sara Sandoval-Carrillo ◽  
...  

Aim/background: in view of the growing demand for food, new methodologies are needed to improve the genomic selection (GS) methodology to obtain more productive plant varieties and there is empirical evidence that GS it is revolutionizing plant breeding for food production around the world. Methods: since the prediction models play a key role in GS, for this reason Montesinos-López et al. (2018) proposed the item based collaborative filtering (IBCF) algorithm for Genomic prediction. For this reason, in this paper we compare the IBCF algorithm with the most popular genomic prediction model called the Genomic Best Linear Unbiased Prediction (GBLUP). Results: We found that the GBLUP is superior than the IBCF model, but the IBCF is competitive to the GBLUP model since produced very similar predictions, but with the large advantage that it is extremely efficient in terms of time for implementation. Conclusions: we found that the GBLUP is better than the IBCF algorithm but the IBCF is more than 400 times more efficient than the GBLUP model in terms of time for implementation. Limitations: The main limitation of the study is that it was performed in univariate terms and it is possible that the IBCF will perform better with multivariate data.RESUMENObjetivo / antecedentes: en vista de la creciente demanda de alimentos, se necesitan nuevas metodologías para mejorar la selección genómica (GS) para obtener variedades de plantas más productivas y en menor tiempo y existe evidencia que la SG está revolucionando el mejoramiento de plantas que ayudará a incrementar la producción de alimentos a nivel mundial. Métodos: dado que los modelos de predicción juegan un papel clave en GS, Montesinos-López et al. (2018) propusieron el algoritmo de filtrado colaborativo (IBCF) para la predicción genómica. Por esta razón, en este artículo comparamos el algoritmo IBCF con el modelo de predicción genómica más popular denominado mejor predictor lineal insesgado Bayesiano (GBLUP). Resultados: Encontramos que el GBLUP es superior en capacidad predictiva al modelo IBCF, pero el IBCF es competitivo con el modelo GBLUP ya que produjo predicciones muy similares, pero con la ventaja de que es eficiente en términos de tiempo de implementación. Conclusiones: encontramos que el GBLUP es mejor que el algoritmo IBCF, pero el IBCF es 400 veces más eficiente que el modelo GBLUP en términos de tiempo de implementación. Limitaciones: la principal limitación del estudio es que se realizó en términos univariados y es posible que el IBCF se desempeñe mejor con datos multivariados.


Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1013
Author(s):  
Bryan Irvine Lopez ◽  
Seung-Hwan Lee ◽  
Jong-Eun Park ◽  
Dong-Hyun Shin ◽  
Jae-Don Oh ◽  
...  

The authors wish to make the following corrections to this paper [...]


Author(s):  
B Grundy ◽  
WG Hill

An optimum way of selecting animals is through a prediction of their genetic merit (estimated breeding value, EBV), which can be achieved using a best linear unbiased predictor (BLUP) (Henderson, 1975). Selection decisions in a commercial environment, however, are rarely made solely on genetic merit but also on additional factors, an important example of which is to limit the accumulation of inbreeding. Comparison of rates of inbreeding under BLUP for a range of hentabilities highlights a trend of increasing inbreeding with decreasing heritability. It is therefore proposed that selection using a heritability which is artificially raised would yield lower rates of inbreeding than would otherwise be the case.


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