Genetic diversity and allelic richness in Spanish wild and domestic pig population estimated from microsatellite markers

J Rodrigáñez,C Gortázar,E Alves,M.A Toro,L Silió,C Barragán

doi:10.5424/sjar/200806s1-379

J Rodrigáñez, C Gortázar + Show 4 more

Open Access

https://doi.org/10.5424/sjar/200806s1-379

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Abstract

Genetic diversity measures support the conservation decisions aiming to maintain the genetic flexibility of animal populations and breeds. Many of these measures utilize neutral genetic markers and are based on classical concepts as coancestry and expected heterozygosity. As a component of genetic diversity, allelic richness is also important in conservation genetics. Its measurement requires that variations of sample size be taken into account using either the rarefaction and extrapolation techniques. Methods to estimate genetic diversity and allelic richness were compared in this study. DNA samples from 68 wild boars and 234 domestic pigs of the Duroc and Iberian breeds, including 63 animals of the Torbiscal and Guadyerbas Iberian lines, were genotyped for 18 microsatellites (one per autosome). As the results outline, the rank of these pig populations according to their contributions to the diversity will be different depending on the criteria utilized, because genetic diversity and private allelic richness do not exactly address the same type of diversity. Rarefaction and extrapolation-based techniques also produce partially discrepant results. The desirable integration of allelic richness into the diversity theory poses at the moment some unsolved difficulties.

Highlights

Diversidad genética y riqueza alélica en poblaciones españolas de cerdos y jabalíes estimadas a partir de marcadores microsatélite
The methods employed for calculating genetic distances to infer relationships within and among breeds are poorly suited for managing within-breed genetic diversity and for setting between breeds conservation priorities (MacHugh et al, 1998)
Caballero and Toro (2002) consider these methods inappropriate for within-species breed conservation, because genetic variation within groups is ignored in this approach, it may be of great importance for the management of livestock breeds

Summary

Introduction

Diversidad genética y riqueza alélica en poblaciones españolas de cerdos y jabalíes estimadas a partir de marcadores microsatélite. Phylogenetic techniques based on genetic distances estimated from microsatellites have been the method of choice to assess the genetic diversity of livestock breeds (Barker, 1999). Other statistical tools, focused to the partition of genetic diversity within and between breeds, and based on the classical concepts of coancestry and expected heterozygosity, have been proposed to analyse genetic diversity in populations of livestock species (Toro et al, 2007). The objective of this study was to apply these new statistical tools for assessing the genetic and allelic diversity in a set of wild boar and domestic pig populations, and for exemplifying the difficulties of their possible application to the definition of conservation priorities

Objectives

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Results