Abstract：
The Pura Raza Español (PRE) is an autochthonous Spanish horse population distributed in 65 countries and managed by a single association. Since 1960s, breeding animals have been steadily exported to other countries to establish local subpopulations. We analysed the genetic structure of a PRE horse meta-population (MP) of 215,500 animals from countries with at least 80 active animals (27 countries comprising 77% of the total animals in the complete pedigree). Genotypes from active animals (59% of the total animals in the complete pedigree) were also studied. Genetic analysis of the MP was performed using classical parameters such as inbreeding (F), coancestry, founder contribution, effective number of founders/ancestors (fe/fa) and gene flow between countries. Results showed that the MPF coefficient decreased in the last two decades (1990-2013), indicating an explicit management against F. Founder contribution to genetic variability across countries mainly came from females (73.6%). In general, unbalanced contributions of founders reflected the high loss of genetic diversity along generations (fe/fa as low as 32/19 for the whole MP). Despite this differential contribution, the proportional contribution to the global diversity of each country was similar. The highest within-country coancestry value corresponded to Cuba (0.1509), being the only country with highly inbred individuals (over 12%), and the lowest value corresponded to Spain (0.0574). These results should help to avoid further declines in genetic variability and increases in F levels, especially in small countries like Cuba. In parallel, only nine countries presented descendants in a single population, suggesting a common origin for all countries and/or a substantial exchange of genetic material between populations. Spain and the US showed the highest gene flow rates. These results support the need of a coordinated management strategy, especially promoting the exchange of genetic material to increase the effective population size and maintain the levels of genetic diversity in the PRE horse population.
摘要：
PuraRazaEspañol（PRE）是西班牙本土马种群，分布在65个国家，由一个协会管理。自1960年代以来,繁殖动物已稳定地出口到其他国家，以建立当地的亚种群。我们分析了来自至少有80只活跃动物的国家（27个国家，占完整谱系中总动物的77％）的215,500只动物的PRE马群体（MP）的遗传结构。还研究了来自活性动物的基因型(完整谱系中总动物的59%)。使用经典参数如近亲繁殖(F)进行MP的遗传分析，coancestry,创始人的贡献,国家间创始人/祖先的有效数量(fe/fa)和基因流动。结果显示，强积金系数在过去20年(1990-2013年)有所下降，这表明对F的明确管理。创始人对各国遗传变异的贡献主要来自女性(73.6%)。总的来说,创始人的不平衡贡献反映了世代遗传多样性的高度丧失（整个MP的fe/fa低至32/19）。尽管有这种不同的贡献，每个国家对全球多样性的贡献比例相似。国内最高的血统值对应于古巴(0.1509)，是唯一一个拥有高度近亲繁殖个体(超过12%)的国家，最低值对应于西班牙(0.0574)。这些结果应该有助于避免遗传变异性的进一步下降和F水平的增加。尤其是像古巴这样的小国。并行,只有九个国家在一个人口中呈现后代，建议所有国家的共同起源和/或种群之间遗传物质的大量交换。西班牙和美国的基因流速最高。这些结果支持了协调管理战略的需要，特别是促进遗传物质的交换，以增加有效种群规模并保持PRE马种群的遗传多样性水平。
