The root of the East African cichlid radiations
The root of the East African cichlid radiations
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DOI：
10.1186/1471-2148-9-186
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发表时间：
2009-08-05
影响因子：
3.4
通讯作者：
Schliewen, Ulrich K.
中科院分区：
文献类型：
--
作者：
Schwarzer, Julia;Misof, Bernhard;Schliewen, Ulrich K.
背景：几十年来，东非地区的慈鱼一直是研究物种形成过程和寻找潜在物种形成关键因素的天然实验对象。尽管有大量的系统发育研究涉及到它们的类群内关系，但令人惊讶的是，人们对这个神秘类群的系统发育位置和起源时间知之甚少。我们使用了来自5个核基因和4个线粒体基因的多位点DNA序列数据和改进的发散时间估计来填补这一知识空白。结果：与以往的研究一致，东非慈鱼辐射的根嵌套在所谓的“罗非鱼”中，这是一个副生殖组合。首次明确了罗非鱼的类群间关系，建立了三个新的单系类群：“Oreochromini”、“Boreotilapiini”和一个在东非和中非有分布中心的类群“Austrotilapiini”。后者是东非辐射的始祖谱系，出现在中新世/渐新世边界，大约14~26 mm。结论：我们的研究结果为东非巨型鱼类辐射以及世界第二大水产养殖物种尼罗罗非鱼和尼罗罗非鱼的系统发育位置提供了第一个可靠的假说。我们的分析不仅为非洲叶蝉的系统发育和系统学奠定了坚实的基础，而且为即将到来的进化生物学和水产养殖的比较系统学研究提供了一个有效和必要的框架。
Background: For decades cichlid fishes (Perciformes: Cichlidae) of the East African cichlid radiations (Teleostei: Cichlidae) have served as natural experimental subjects for the study of speciation processes and the search for potential speciation key factors. Despite numerous phylogenetic studies dealing with their intragroup relationships, surprisingly little is known about the phylogenetic placement and time of origin of this enigmatic group. We used multilocus DNA-sequence data from five nuclear and four mitochondrial genes and refined divergence time estimates to fill this knowledge gap.Results: In concordance with previous studies, the root of the East African cichlid radiations is nested within the so called "Tilapias", which is a paraphyletic assemblage. For the first time, we clarified tilapiine intragroup relationships and established three new monophyletic groups:"Oreochromini", "Boreotilapiini" and a group with a distribution center in East/Central Africa, the "Austrotilapiini". The latter is the founder lineage of the East African radiations and emerged at the Miocene/Oligocene boundary at about 14 to 26 mya.Conclusion: Our results provide the first resolved hypothesis for the phylogenetic placement of the megadiverse East African cichlid radiations as well as for the world's second most important aquaculture species, the Nile Tilapia, Oreochromis niloticus. Our analyses constitute not only a robust basis for African cichlid phylogenetics and systematics, but provide a valid and necessary framework for upcoming comparative phylogenomic studies in evolutionary biology and aquaculture.