Quantifying and managing the loss of genetic variation in a free-ranging population of takahe through the use of pedigrees
Quantifying and managing the loss of genetic variation in a free-ranging population of takahe through the use of pedigrees
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DOI：
10.1007/s10592-007-9390-3
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发表时间：
2008-06-01
影响因子：
2.2
通讯作者：
Jamieson, Ian G.
中科院分区：
文献类型：
--
作者：
Grueber, Catherine E.;Jamieson, Ian G.
系谱分析通过评估近亲繁殖、种群结构和遗传多样性，对受威胁种群的遗传管理有明显的好处。系谱的使用通常仅限于圈养种群，很少有例子存在其专门用于管理自由放养种群。其中一个例子是对塔卡河（Porphyrio hochstetteri）的管理，这是一种高度濒危的、不会飞的新西兰秧鸡，面临着引入哺乳动物捕食者和栖息地丧失的风险。在20世纪80年代和90年代，作为塔卡河恢复计划的一部分，鸟类从峡湾唯一的残余种群转移到四个近海岛屿，从那里引进的捕食者已经被消灭。随后的“岛屿”人口目前已达到83人，被认为已达到承载能力，自成立以来一直受到密切监测。详细的繁殖记录使我们能够分析岛上的血统，这是多达7代深。基因下降分析表明，7.5%的遗传多样性已经失去了相对较短的时间内，因为成立（平均2.1代;总遗传创始人= 31）由于未能均衡的创始人代表早期和随后的不成比例的育种成功（创始人当量= 12.5;创始人基因组当量= 6.6）。近亲繁殖的高度流行也会影响遗传多样性。系谱模型的预测表明，90%的遗传多样性将保持只有12年，但通过引入低水平的移民从峡湾人口，并允许人口增长，90%的GD可以保持在未来100年。更一般地说，这些结果证明了保持野生种群谱系的价值，特别是在易位事件发生后的几年内。
Pedigree analysis has clear benefits for the genetic management of threatened populations through the evaluation of inbreeding, population structure and genetic diversity. The use of pedigrees is usually restricted to captive populations and few examples exist of their exclusive use in managing free-ranging populations. One such example is the management of the takahe (Porphyrio hochstetteri), a highly endangered, flightless New Zealand rail at risk from introduced mammalian predators and habitat loss. During the 1980's and 90's, as part of the takahe recovery programme, birds were translocated from the sole remnant population in Fiordland to four offshore islands from which introduced predators had been eradicated. The subsequent "island" population, now numbering 83 and thought to be at carrying capacity, has been closely monitored since founding. Detailed breeding records allow us to analyse the island pedigree, which is up to 7 generations deep. Gene-drop analysis indicated that 7.5% of genetic diversity has been lost over the relatively short timeframe since founding (2.1 generations on average; total genetic founders = 31) due to both a failure to equalise founder representation early on and subsequent disproportionate breeding success (founder equivalents = 12.5; founder genome equivalents = 6.6). A high prevalence of close inbreeding will have also impacted on genetic diversity. Predictions from pedigree modelling suggest that 90% genetic diversity will be maintained for only 12 years, but by introducing a low level of immigration from the Fiordland population and permitting the population to grow, 90% GD could be maintained over the next 100 years. More generally, the results demonstrate the value of maintaining pedigrees for wild populations, especially in the years immediately after a translocation event.