Elias Becky A, Shipley Lisa A, McCusker Sarah, Sayler Rodney D, Johnson Timothy R
115 Johnson Hall, School of the Environment, Washington State University, Pullman, WA 99164-6410, USA.
Center for Reproductive Biology, Washington State University, Pullman, WA 99164, USA.
J Mammal. 2013 Dec 16;94(6):1282-1292. doi: 10.1644/12-MAMM-A-224.1.
A quarter of all lagomorph species worldwide are threatened with extinction. Captive breeding programs, such as that developed for the Columbia Basin (CB) pygmy rabbit (), sometimes are implemented as emergency conservation measures to restore small, genetically distinct populations. However, small source populations also may have low genetic diversity, which may influence attributes related to fitness, including growth, survival, and reproduction. We used mixed-effects regression models to explore the influence of genetic pedigree (% CB) on pairing success, growth, and survival during the 10-year captive breeding program at Washington State University, which included controlled pairings and outbreeding with pygmy rabbits from Idaho. Pairing success, juvenile growth, and juvenile survival declined with increasing CB pedigree of 1 or both parents, suggesting inbreeding depression among the small number of related founders. Demographic variables such as age, sex, and previous pregnancies, and environmental variables such as month and temperature at birth also were associated with production of pygmy rabbits. Our study illustrates the difficulty of retaining a unique genome of a small source population while simultaneously producing enough rabbits for restoration into natural habitat as part of endangered species recovery programs.
全球四分之一的兔形目物种面临灭绝威胁。圈养繁殖计划，比如为哥伦比亚盆地（CB）侏儒兔制定的计划，有时会作为紧急保护措施来恢复小型、基因独特的种群。然而，小型源种群的遗传多样性也可能较低，这可能会影响与适应性相关的特征，包括生长、存活和繁殖。我们使用混合效应回归模型，在华盛顿州立大学开展的为期10年的圈养繁殖计划中，探究遗传谱系（%CB）对配对成功率、生长和存活的影响，该计划包括控制性配对以及与爱达荷州的侏儒兔进行远系繁殖。随着亲本一方或双方的CB谱系增加，配对成功率、幼兔生长和幼兔存活均下降，这表明在少数有亲缘关系的奠基者中存在近亲衰退现象。年龄、性别和既往妊娠等人口统计学变量，以及出生月份和温度等环境变量也与侏儒兔的繁殖有关。我们的研究表明，在作为濒危物种恢复计划的一部分，为恢复自然栖息地而培育足够数量兔子的同时，保留小型源种群独特基因组存在困难。
