Molecular phylogeny of Oreochromis (Cichlidae: Oreochromini) reveals mito-nuclear discordance and multiple colonisation of adverse aquatic environments
Molecular phylogeny of Oreochromis (Cichlidae: Oreochromini) reveals mito-nuclear discordance and multiple colonisation of adverse aquatic environments
复制标题
DOI：
10.1016/j.ympev.2019.04.008
复制
发表时间：
2019-07-01
影响因子：
4.1
通讯作者：
Day, Julia J.
中科院分区：
文献类型：
--
作者：
Ford, Antonia G. P.;Bullen, Thomas R.;Day, Julia J.
虽然大多数慈鲷鱼的多样性发生在非洲五大湖，这些鱼也在整个非洲大陆多样化。这种发生在河流和湖泊中的大陆辐射远不如湖泊辐射受到关注，尽管有些成员，如oreochromine慈鲷（通常称为“罗非鱼”），在其原生范围内外都具有重要的科学和社会经济意义。在慈鲷科鱼类中，Oreochromis属的几个物种表现出对苏打水条件的适应性（包括对高温和盐度的耐受性），这是进化生物学研究和水产养殖角度的兴趣。关于促进这一群体多样化的因素仍然存在问题，迄今尚未在系统发育框架内加以解决。在这里，我们基于线粒体（1583 bp）和核（3092 bp）序列数据，首次全面（32/37个已描述物种）介绍了口丽鱼和密切相关的Alcolapia的多标记分子系统发育。我们发现核DNA和线粒体DNA树之间存在广泛的不一致。这可能是不完整的谱系分选和/或在线粒体基因座的基因渗入的结果，虽然我们没有发现后者的强信号。基于我们的核发育，我们表明，适应不利条件（盐度升高，温度，或碱度）已发生多次在Oreochromis，但适应极端（苏打）条件（高盐度，温度，和碱度）可能已经出现一次在血统导致O。amphimelas和Alcolapia。我们还表明Alcolapia嵌套在Oreochromis内，这是与以前的研究一致，在这里修改分类学的同义词属Oreochromis，保留指定为亚属Oreochromis（Alcolapia）。
Although the majority of cichlid diversity occurs in the African Great Lakes, these fish have also diversified across the African continent. Such continental radiations, occurring in both rivers and lakes have received far less attention than lacustrine radiations despite some members, such as the oreochromine cichlids (commonly referred to as 'tilapia'), having significant scientific and socio-economic importance both within and beyond their native range. Unique among cichlids, several species of the genus Oreochromis exhibit adaptation to soda conditions (including tolerance to elevated temperatures and salinity), which are of interest from evolutionary biology research and aquaculture perspectives. Questions remain regarding the factors facilitating the diversification of this group, which to date have not been addressed within a phylogenetic framework. Here we present the first comprehensive (32/37 described species) multi-marker molecular phylogeny of Oreochromis and closely related Alcolapia, based on mitochondrial (1583 bp) and nuclear (3092 bp) sequence data. We show widespread discordance between nuclear DNA and mitochondrial DNA trees. This could be the result of incomplete lineage sorting and/or introgression in mitochondrial loci, although we did not find a strong signal for the latter. Based on our nuclear phylogeny we demonstrate that adaptation to adverse conditions (elevated salinity, temperature, or alkalinity) has occurred multiple times within Oreochromis, but that adaptation to extreme (soda) conditions (high salinity, temperature, and alkalinity) has likely arisen once in the lineage leading to O. amphimelas and Alcolapia. We also show Alcolapia is nested within Oreochromis, which is in agreement with previous studies, and here revise the taxonomy to synonymise the genus in Oreochromis, retaining the designation as subgenus Oreochromis (Alcolapia).