Mouse (Mus musculus) stocks derived from tropical islands:: new models for genetic analysis of life-history traits
Mouse (Mus musculus) stocks derived from tropical islands:: new models for genetic analysis of life-history traits
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DOI：
10.1111/j.1469-7998.2000.tb00580.x
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发表时间：
2000-01-01
影响因子：
2
通讯作者：
Austad, S
中科院分区：
文献类型：
--
作者：
Miller, RA;Dysko, R;Austad, S
创始人效应，再加上获得空置的生态位，可能会让孤立岛屿上的啮齿动物种群进化出不同于大陆亲戚的生活史特征集群，例如在身体大小、窝大小和寿命方面。特别是，在捕食者数量减少且不受严酷冬季气候影响的岛屿上，固有死亡风险较低，原则上可能有助于发展寿命更长的种群。相反，实验室啮齿动物通常繁殖的条件被认为是选择那些产生早期繁殖率高但寿命降低的大型、快速成熟的种族的基因型。为了测试这些想法，并产生适合于对生命历史事件发生的过程进行遗传和分子分析的新小鼠种群，我们从来自三个不同种群的小鼠中开发了特定的无病原体种群：美国大陆(爱达荷州)和热带太平洋岛屿马朱罗和波恩佩。研究发现，来自这三个地点的小鼠比来自四个常见实验室近亲繁殖品系的遗传异质性种群的小鼠更矮、更轻，产仔更少，粪便皮质酮水平更高。在野生来源的种群中，来自波恩佩和马朱罗的小鼠明显比来自爱达荷州的动物更轻、更矮，即使在相同的住房条件下出生的种群也是如此。三个野生种群之间的产仔数和繁殖成功率没有显著差异。虽然还需要进一步的工作，以确定野生来源的种群是否如预测的那样彼此不同，以及与实验室小鼠的寿命是否不同，但这些种群为调节身体大小和繁殖成功的因素的基因解剖提供了有用的工具。
Founder effects, together with access to unoccupied ecological niches, may allow rodent populations on isolated islands to evolve constellations of life-history traits that distinguish them from their mainland relatives, for example in body size, litter size, and longevity. In particular, low intrinsic mortality risks on islands with reduced predator numbers and not subject to harsh winter climates may in principle support the development of stocks with extended longevity. Conversely, the conditions under which laboratory rodents are typically bred are thought to select for genotypes that produce large, rapidly maturing races with high early reproductive rates but diminished longevity. To test these ideas, and to generate new mouse stocks suitable for genetic and molecular analysis of the processes that time life-history events, we have developed specific pathogen-free stocks from mice trapped from three distinct populations: the U.S. mainland (Idaho) and the tropical Pacific islands Majuro and Pohnpei. Mice from all three locations were found to be shorter and lighter, to have smaller litters, and to have higher faecal corticosterone levels than mice of a genetically heterogeneous stock derived from four common laboratory inbred strains. Among the wild-derived stocks, mice from Pohnpei and Majuro were significantly lighter and shorter than Idaho-derived animals, even in populations kept from birth under identical housing conditions. Litter size and reproductive success rates did not differ significantly among the three wild-derived stocks. Although further work will be needed to see if, as predicted, the wild-derived stocks differ from one another and from laboratory mice in longevity, these stocks provide useful tools for genetic dissection of factors that regulate body size and reproductive success.