The Site Frequency/Dosage Spectrum of Autopolyploid Populations

The Site Frequency Spectrum (SFS) and the heterozygosity of allelic variants are among the most important summary statistics for population genetic analysis of diploid organisms. We discuss the generalization of these statistics to populations of autopolyploid organisms in terms of the joint Site Fr...

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Detalhes bibliográficos
Autores: Ferretti, Luca, Ribeca, Paolo, Ramos-Onsins, Sebastian E.
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/397524
Acesso em linha:http://hdl.handle.net/10261/397524
https://api.elsevier.com/content/abstract/scopus_id/85100730936
Access Level:acceso abierto
Palavra-chave:Hardy-Weinberg equilibrium
Allelic dosage
Autopolyploidy
Dosage distribution
Heterozygosity
High-throughput sequencing
Neutrality tests
Site frequency spectrum
Descrição
Resumo:The Site Frequency Spectrum (SFS) and the heterozygosity of allelic variants are among the most important summary statistics for population genetic analysis of diploid organisms. We discuss the generalization of these statistics to populations of autopolyploid organisms in terms of the joint Site Frequency/Dosage Spectrum and its expected value for autopolyploid populations that follow the standard neutral model. Based on these results, we present estimators of nucleotide variability from High-Throughput Sequencing (HTS) data of autopolyploids and discuss potential issues related to sequencing errors and variant calling. We use these estimators to generalize Tajima's D and other SFS-based neutrality tests to HTS data from autopolyploid organisms. Finally, we discuss how these approaches fail when the number of individuals is small. In fact, in autopolyploids there are many possible deviations from the Hardy-Weinberg equilibrium, each reflected in a different shape of the individual dosage distribution. The SFS from small samples is often dominated by the shape of these deviations of the dosage distribution from its Hardy-Weinberg expectations.