Van de Putte Anton P, Janko Karel, Kasparova Eva, Maes Gregory E, Rock Jennifer, Koubbi Philippe, Volckaert Filip A M, Choleva Lukáš, Fraser Keiron P P, Smykla Jerzy, Van Houdt Jeroen K J, Marshall Craig
Laboratory of Biodiversity and Evolutionary Genomics, KU Leuven, Ch. Deberiotstraat 32, B-3000 Leuven, Belgium.
Mar Genomics. 2012 Dec;8:23-34. doi: 10.1016/j.margen.2012.05.002. Epub 2012 Jun 23.
Population genetics patterns of marine fish in general and of Southern Ocean fish in particular range from virtual panmixia over ocean-wide scale to deeply fragmented populations. However the causes underlying these different patterns are not properly understood. In this paper, we tested the hypotheses that population connectivity is positively related to a combination of life history traits, namely duration of pelagic larval period and the tendency towards pelagic life style in the adulthood. To do so, we analysed the variability of six microsatellite and one mitochondrial marker (cytochrome b) in three Southern Ocean fish species (Trematomus newnesi, Trematomus hansoni and Trematomus bernacchii). They share a recent common ancestor but notably differ in their duration of pelagic larval period as well as pelagic versus benthic lifestyle. We sampled over a range of more than 5000 km for all three species and used a number of population genetics tools to investigate past and contemporary levels of connectivity. All species experienced population fluctuations, but coalescent simulations suggested that contemporary populations are in migration-drift equilibrium. Although global F(ST) values were rather low, a significant population structure separated the High-Antarctic from the Peninsular regions in all species. The level of genetic differentiation was much lower in the pelagic versus benthic species. Present data suggest that past and present genetic structuring in the Southern Ocean are indeed related with the ecological traits of Antarctic fish, however the relative importance of individual factors remains unclear.
一般来说，海洋鱼类尤其是南大洋鱼类的种群遗传模式，从大洋尺度上近乎随机交配到种群深度隔离各不相同。然而，这些不同模式背后的原因尚未得到充分理解。在本文中，我们检验了以下假设：种群连通性与一系列生活史特征呈正相关，即浮游幼体期的持续时间以及成年期浮游生活方式的倾向。为此，我们分析了三种南大洋鱼类（新氏南极鱼、汉氏南极鱼和伯氏南极鱼）的六个微卫星标记和一个线粒体标记（细胞色素b）的变异性。它们有着较近的共同祖先，但在浮游幼体期的持续时间以及浮游与底栖生活方式上存在显著差异。我们对所有这三个物种在超过5000公里的范围内进行了采样，并使用了多种种群遗传学工具来研究过去和当代的连通性水平。所有物种都经历了种群波动，但溯祖模拟表明当代种群处于迁移 - 漂变平衡状态。尽管全局F(ST)值相当低，但在所有物种中，一个显著的种群结构将高南极地区与半岛地区分隔开来。浮游物种与底栖物种相比，遗传分化水平要低得多。目前的数据表明，南大洋过去和现在的遗传结构确实与南极鱼类的生态特征相关，然而各个因素的相对重要性仍不明确。
