Spatial autocorrelation analysis offers new insights into gene flow in the Australian bush rat, Rattus fuscipes
Spatial autocorrelation analysis offers new insights into gene flow in the Australian bush rat, Rattus fuscipes
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DOI：
10.1111/j.0014-3820.2003.tb00327.x
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发表时间：
2003-05-01
期刊：
影响因子：
3.3
通讯作者：
Lindenmayer, DB
中科院分区：
文献类型：
--
作者：
Peakall, R;Ruibal, M;Lindenmayer, DB
扩散是影响物种对景观变化和栖息地破碎化反应的基本过程。为了更好地了解澳大利亚丛林鼠（Rattus fuscipes）的扩散，我们将一种新的多位点自相关方法与超变微卫星遗传标记相结合，以研究精细尺度（小于或等于 1 km）的空间分布模式和空间遗传结构。该研究在四个地点的八个诱捕样带上进行，总共采样了 270 只动物。丛林鼠分布的空间自相关分析表明，一般来说，动物以较高密度（小于或等于 200 米）的群体或集群出现，中间有间隙或密度较低的区域。基于总共 80 个等位基因的 7 个高变微卫星位点 (He = 0.8) 的空间遗传自相关分析揭示了显着正局部遗传结构的一致模式。这种遗传模式对于所有样带、成虫和亚成虫、雄性和雌性都是一致的。通过在10到800 m的多个尺度上测试自相关，我们发现可检测的正空间遗传结构的范围超过了500 m。进一步分析发现，雄性的空间遗传结构明显弱于雌性，但成虫和亚成虫之间没有发现显着差异。 Mantel 测试和分层 AMOVA 的结果进一步支持这样的结论：在我们的研究范围内，丛林鼠基因型的分布不是随机的。相反，距离较近的丛林鼠比距离较远的动物在基因上更加相似。我们得出的结论是，在丛林大鼠中，每代基因流受到充分限制，足以产生局部空间遗传结构的强烈正信号。尽管我们的结果与动物运动的现场数据一致，包括报道的雄性比雌性运动更远的趋势，但我们提供了第一个证据表明丛林鼠基因流动受到限制。我们的研究似乎是第一个基于微卫星的小型哺乳动物精细遗传变异研究，也是第一个报告跨地点、年龄组和性别的一致的积极局部遗传结构的研究。新形式的自相关分析、高变量遗传标记和精细分析（10 公里）群体遗传学研究的结合。
Dispersal is a fundamental process that influences the response of species to landscape change and habitat fragmentation. In an attempt to better understand dispersal in the Australian bush rat, Rattus fuscipes, we have combined a new multilocus autocorrelation method with hypervariable microsatellite genetic markers to investigate fine-scale (less than or equal to1 km) patterns of spatial distribution and spatial genetic structure. The study was conducted across eight trapping transects at four sites, with a total of 270 animals sampled. Spatial autocorrelation analysis of bush rat distribution revealed that, in general, animals occurred in groups or clusters of higher density (less than or equal to200 m across), with intervening gaps or lower density areas. Spatial genetic autocorrelation analysis, based on seven hypervariable microsatellite loci (He = 0.8) with a total of 80 alleles, revealed a consistent pattern of significant positive local genetic structure. This genetic pattern was consistent for all transects, and for adults and sub-adults, males and females. By testing for autocorrelation at multiple scales from 10 to 800 m we found that the extent of detectable positive spatial genetic structure exceeded 500 m. Further analyses detected significantly weaker spatial genetic structure in males compared with females, but no significant differences were detected between adults and sub adults. Results from Mantel tests and hierarchical AMOVA further support the conclusion that the distribution of bush rat genotypes is not random at the scale of our study. Instead, proximate bush rats are more genetically alike than more distant animals. We conclude that in bush rats, gene flow per generation is sufficiently restricted to generate the strong positive signal of local spatial genetic structure. Although our results are consistent with field data on animal movement, including the reported tendency for males to move further than females, we provide the first evidence for restricted gene flow in bush rats. Our study appears to be the first microsatellite-based study of fine-scale genetic variation in small mammals and the first to report consistent positive local genetic structure across sites, age-classes, and sexes. The combination of new forms of autocorrelation analyses, hypervariable genetic markers and fine-scale analysis (10 km) population genetic studies.