FACTORS ELIMINATING INBREEDING DEPRESSION IN A CAPTIVE HERD OF SPEKES GAZELLE (GAZELLA-SPEKEI)
FACTORS ELIMINATING INBREEDING DEPRESSION IN A CAPTIVE HERD OF SPEKES GAZELLE (GAZELLA-SPEKEI)
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DOI：
10.1002/zoo.1430030302
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发表时间：
1984-01-01
期刊：
影响因子：
1.3
通讯作者：
READ, B
中科院分区：
文献类型：
--
作者：
TEMPLETON, AR;READ, B
近亲繁殖通常与生存能力和出生体重的降低有关，这种现象被称为近亲繁殖衰退。一个严重的近亲繁殖抑郁症是遇到了圈养繁殖计划斯皮克的瞪羚。不幸的是，简单地避免近亲繁殖的解决方案无法实施，因为整个牛群都是由一只进口雄性和三只进口雌性后代组成的。由于这种创始人效应，近亲繁殖是不可能避免的。然而，果蝇的实验室实验和基本的进化理论表明，动物可以通过选择性消除导致近亲繁殖抑制的基因来迅速适应近亲繁殖。这些实验和理论结果被转化为斯皮克瞪羚的育种计划。育种计划的第一个目标是人口目标：尽可能快地将总人口规模增加到承载能力。其他目标都涉及父母或后代的遗传属性：父母和后代都应该是近亲繁殖的，父母和后代都应该有尽可能多的不同创始祖先的基因。在本文中，我们的文件，这一育种计划确实消除了近亲繁殖的抑郁症非常迅速，而且，该计划的遗传目标，帮助这种消除完全符合理论预测。此外，我们的分析清楚地表明，瞪羚遭受了近亲繁殖的抑郁症，而不是异交抑郁症。我们的结论是，近亲繁殖衰退可以通过适当的育种计划迅速有效地减少，因此近亲繁殖衰退并不构成一个无法避免近亲繁殖的物种长期维持的不可逾越的障碍。
Inbreeding is commonly associated with a lowering of viability and birth weights—a phenomenon known as inbreeding depression. A severe inbreeding depression was encountered in a captive breeding program for Speke's gazelle. Unfortunately, the solution of simply avoiding inbreeding could not be implemented because the entire herd was descended from one import male and three import females. Because of this founder effect, it was impossible to avoid inbreeding. However, laboratory experiments with fruit flies and basic evolutionary theory indicate that animals can rapidly adapt to inbreeding by the selective elimination of the genes responsible for inbreeding depression. These experimental and theoretical results were translated into a breeding program for the Speke's gazelle. The first goal of the breeding program is a demographic goal: increase the total population size as rapidly as possible to the carrying capacity. The other goals all deal with genetic attributes of either parents or offspring: Both parents and offspring should be inbred, and both parents and offspring should have genes from as many different founding ancestors as possible. In this paper, we document that this breeding program does eliminate the inbreeding depression very rapidly, and moreover that the genetic goals of the program aid this elimination exactly as theory predicts. Furthermore, our analysis clearly shows that the gazelles suffered from an inbreeding depression rather than an outcrossing depression. We conclude that inbreeding depressions can be rapidly and effectively reduced by an appropriate breeding program, and hence an inbreeding depression does not constitute an insurmountable barrier to the long‐term maintenance of a species in which inbreeding cannot be avoided.