Multi-locus Analyses Reveal Four Giraffe Species Instead of One
Multi-locus Analyses Reveal Four Giraffe Species Instead of One
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DOI：
10.1016/j.cub.2016.07.036
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发表时间：
2016-09-26
期刊：
影响因子：
9.2
通讯作者：
Janke, Axel
中科院分区：
文献类型：
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作者：
Fennessy, Julian;Bidon, Tobias;Janke, Axel
传统上，已识别出一种长颈鹿物种和多达十一个亚种[1]；然而，九个亚种被普遍接受[2]。即使经过一个世纪的研究，每个长颈鹿亚种的独特性仍不清楚，并且其分布范围内的遗传变异尚未完全探索。最近对 mtDNA 的遗传学研究表明，九个假定亚种中的七个亚种之间存在母系互惠单系性 [3, 4]。此外，到目前为止，遗传分析尚未应用于双亲遗传序列数据，也不包括所有九个长颈鹿亚种的数据。我们对非洲各地的自然长颈鹿种群进行了采样，并首次将提名亚种努比亚长颈鹿 Giraffacamelopardaliscamelopardalis Linnaeus 1758 [5] 的个体纳入遗传分析中。基于合并的多位点和群体遗传分析确定了至少四个独立的单系进化枝，根据遗传分离标准，它们应被识别为四个不同的长颈鹿物种。对来自母体和双亲标记的 190 个个体的分析支持了这些发现，并进一步建议将罗斯柴尔德长颈鹿归入努比亚长颈鹿，以及将索尼克罗夫特长颈鹿归入马赛长颈鹿 [6]。长颈鹿基因组调查从微卫星、移动遗传元件和准确的分歧时间估计中产生了有价值的数据。我们的研究结果提供了迄今为止对长颈鹿关系最全面的分析，并表明它们的遗传复杂性被低估了，这凸显了对世界上最高的哺乳动物加大保护力度的必要性。
Traditionally, one giraffe species and up to eleven subspecies have been recognized [1]; however, nine subspecies are commonly accepted [2]. Even after a century of research, the distinctness of each giraffe subspecies remains unclear, and the genetic variation across their distribution range has been incompletely explored. Recent genetic studies on mtDNA have shown reciprocal monophyly of the matrilines among seven of the nine assumed subspecies [3, 4]. Moreover, until now, genetic analyses have not been applied to biparentally inherited sequence data and did not include data from all nine giraffe subspecies. We sampled natural giraffe populations from across their range in Africa, and for the first time individuals from the nominate subspecies, the Nubian giraffe, Giraffa camelopardalis camelopardalis Linnaeus 1758 [5], were included in a genetic analysis. Coalescence-based multi-locus and population genetic analyses identify at least four separate and monophyletic clades, which should be recognized as four distinct giraffe species under the genetic isolation criterion. Analyses of 190 individuals from maternal and biparental markers support these findings and further suggest subsuming Rothschild's giraffe into the Nubian giraffe, as well as Thornicroft's giraffe into the Masai giraffe [6]. A giraffe survey genome produced valuable data from microsatellites, mobile genetic elements, and accurate divergence time estimates. Our findings provide the most inclusive analysis of giraffe relationships to date and show that their genetic complexity has been underestimated, highlighting the need for greater conservation efforts for the world's tallest mammal.