CIISA, Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Lisbon, Portugal.
Genet Sel Evol. 2013 Jun 14;45(1):18. doi: 10.1186/1297-9686-45-18.
Native pig breeds in the Iberian Peninsula are broadly classified as belonging to either the Celtic or the Mediterranean breed groups, but there are other local populations that do not fit into any of these groups. Most of the native pig breeds in Iberia are in danger of extinction, and the assessment of their genetic diversity and population structure, relationships and possible admixture between breeds, and the appraisal of conservation alternatives are crucial to adopt appropriate management strategies.
A panel of 24 microsatellite markers was used to genotype 844 animals representing the 17 most important native swine breeds and wild populations existing in Portugal and Spain and various statistical tools were applied to analyze the results.
Genetic diversity was high in the breeds studied, with an overall mean of 13.6 alleles per locus and an average expected heterozygosity of 0.80. Signs of genetic bottlenecks were observed in breeds with a small census size, and population substructure was present in some of the breeds with larger census sizes. Variability among breeds accounted for about 20% of the total genetic diversity, and was explained mostly by differences among the Celtic, Mediterranean and Basque breed groups, rather than by differences between domestic and wild pigs. Breeds clustered closely according to group, and proximity was detected between wild pigs and the Mediterranean cluster of breeds. Most breeds had their own structure and identity, with very little evidence of admixture, except for the Retinto and Entrepelado varieties of the Mediterranean group, which are very similar. Genetic influence of the identified breed clusters extends beyond the specific geographical areas across borders throughout the Iberian Peninsula, with a very sharp transition from one breed group to another. Analysis of conservation priorities confirms that the ranking of a breed for conservation depends on the emphasis placed on its contribution to the between- and within-breed components of genetic diversity.
Native pig breeds in Iberia reveal high levels of genetic diversity, a solid breed structure and a clear organization in well-defined clusters.
伊比利亚半岛的本地猪种广泛分为凯尔特或地中海品种群，但也有其他不符合这两个品种群的本地种群。伊比利亚半岛的大多数本地猪种都面临灭绝的危险，评估其遗传多样性和群体结构、品种间的关系和可能的混合以及评估保护替代方案对于采取适当的管理策略至关重要。
使用 24 个微卫星标记对代表葡萄牙和西班牙存在的 17 个最重要的本地猪品种和野生种群的 844 只动物进行基因分型，并应用各种统计工具分析结果。
研究品种的遗传多样性很高，每个位点的平均等位基因数为 13.6 个，平均预期杂合度为 0.80。在种群规模较小的品种中观察到遗传瓶颈的迹象，而在一些种群规模较大的品种中存在种群亚结构。品种间的变异性约占总遗传多样性的 20%，主要由凯尔特、地中海和巴斯克品种群之间的差异解释，而不是由家猪和野猪之间的差异解释。品种根据群体聚类紧密，野猪与地中海品种群聚类密切相关。除了地中海品种群的 Retinto 和 Entrepelado 品种非常相似外，大多数品种都有自己的结构和身份，几乎没有混合的证据。确定的品种群的遗传影响超出了特定的地理区域，跨越伊比利亚半岛的边界，从一个品种群到另一个品种群的过渡非常急剧。保护优先级的分析证实，一个品种的保护排名取决于其对品种间和品种内遗传多样性组成部分的贡献程度。
伊比利亚半岛的本地猪种显示出高水平的遗传多样性、坚实的品种结构和明确的组织，形成了明确的聚类。
