Evidence map›Paper›PMID 27716058›Full record

ArticleBMC genomics2016

Ascertainment bias from imputation methods evaluation in wheat.

Sofía P Brandariz, Agustín González Reymúndez, Bettina Lado, Marcos Malosetti, Antonio Augusto Franco Garcia, Martín Quincke, Jarislav von Zitzewitz, Marina Castro, Iván Matus, Alejandro Del Pozo and 2 more

Abstract read
In one paragraph

Article in BMC genomics, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

Sofía P BrandarizStatistics Department, Facultad de Agronomía, Universidad de la República, Garzón 780, Montevideo, 12900, Uruguay.
Agustín González ReymúndezStatistics Department, Facultad de Agronomía, Universidad de la República, Garzón 780, Montevideo, 12900, Uruguay.
Bettina LadoStatistics Department, Facultad de Agronomía, Universidad de la República, Garzón 780, Montevideo, 12900, Uruguay.
Marcos MalosettiBiometris - Applied Statistics, Department of Plant Science, Wageningen University and Research Center, P.O. Box 16, 6700 AA, Wageningen, Netherlands.
Antonio Augusto Franco GarciaDepartamento de Ciências Exatas, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), Universidade de São Paulo (USP), CP 9, CEP 13400-970, Piracicaba, SP, Brazil.
Martín QuinckePrograma Nacional de Investigación Cultivos de Secano, Instituto Nacional de investigación Agropecuaria, Est. Exp. La Estanzuela, Colonia, 70000, Uruguay.
Jarislav von ZitzewitzSecobra Saatzucht GmbH, Feldkirchen 3, 85368, Moosburg, Germany.
Marina CastroPrograma Nacional de Investigación Cultivos de Secano, Instituto Nacional de investigación Agropecuaria, Est. Exp. La Estanzuela, Colonia, 70000, Uruguay.
Iván MatusInstituto de Investigaciones Agropecuarias, Centro Regional de Investigación Quilamapu, Casilla 426, Chillán, Chile.
Alejandro Del PozoFacultad de Ciencias Agrarias, Universidad de Talca, Casilla 747, Talca, Chile.
Ariel J CastroDepartment of Plant Production, Facultad de Agronomía, Universidad de la República, Ruta 3, Km.363, Paysandú, 60000, Uruguay.
Lucía GutiérrezStatistics Department, Facultad de Agronomía, Universidad de la República, Garzón 780, Montevideo, 12900, Uruguay. gutierrezcha@wisc.edu.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundWhole-genome genotyping techniques like Genotyping-by-sequencing (GBS) are being used for genetic studies such as Genome-Wide Association (GWAS) and Genomewide Selection (GS), where different strategies for imputation have been developed. Nevertheless, imputation error may lead to poor performance (i.e. smaller power or higher false positive rate) when complete data is not required as it is for GWAS, and each marker is taken at a time. The aim of this study was to compare the performance of GWAS analysis for Quantitative Trait Loci (QTL) of major and minor effect using different imputation methods when no reference panel is available in a wheat GBS panel.

resultsIn this study, we compared the power and false positive rate of dissecting quantitative traits for imputed and not-imputed marker score matrices in: (1) a complete molecular marker barley panel array, and (2) a GBS wheat panel with missing data. We found that there is an ascertainment bias in imputation method comparisons. Simulating over a complete matrix and creating missing data at random proved that imputation methods have a poorer performance. Furthermore, we found that when QTL were simulated with imputed data, the imputation methods performed better than the not-imputed ones. On the other hand, when QTL were simulated with not-imputed data, the not-imputed method and one of the imputation methods performed better for dissecting quantitative traits. Moreover, larger differences between imputation methods were detected for QTL of major effect than QTL of minor effect. We also compared the different marker score matrices for GWAS analysis in a real wheat phenotype dataset, and we found minimal differences indicating that imputation did not improve the GWAS performance when a reference panel was not available.

conclusionsPoorer performance was found in GWAS analysis when an imputed marker score matrix was used, no reference panel is available, in a wheat GBS panel.

Indexed as

Genome, PlantGenomicsGenome-Wide Association StudyHigh-Throughput Nucleotide SequencingInheritance PatternsPhenotypeQuantitative Trait LociReproducibility of ResultsTriticumFalse positiveGBSGWASPowerQTL

Identifiers

PMID27716058
PMCPMC5050639

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.