论文题目：Judging a salmon by its spots: environmental variation is the primary determinant of spot patterns in Salmo salar
期刊：BMC Ecology
作者：Katarina M. Jørgensen et al.
数字识别码：10.1186/s12898-018-0170-3
你知道三文鱼身上的斑点数可以用于区分野生三文鱼和养殖三文鱼吗？最近一项发表于BMC Ecology的研究表明，相较于基因的微小作用，环境更大程度上决定了养殖三文鱼有更多斑点。
我们已了解到是养殖环境中的某些因素使养殖三文鱼有很多斑点，但引起斑点的准确原因尚不明确，可能是光照、温度、饵料到鱼群密度或增长率中的任何一个因素。
我们研究了特定品种的养殖三文鱼是否具有不同数量的斑点，基于其是在河中孵化还是一直生活在三文鱼养殖场中。
我们将养殖的三文鱼种投放到挪威的Guddal河中，它们孵化并逗留了2-4年。然后我们将这些小三文鱼带出河，转移到位于Matre的研究站，随后在陆上的池塘中养殖两年。然而，这些三文鱼的斑点仍然比一直在Matre标准养殖条件下养殖的三文鱼少了七倍，尽管这些三文鱼来自同一品种。
图片来源：Monica F Solberg，编辑：Katarina Jørgensen
养殖三文鱼和在养殖环境下生长的野生三文鱼都会有很多斑点，而在河中生长的所有养殖和野生三文鱼的斑点较少。这意味着我们可以确定是环境决定了三文鱼有多少斑点。
然而，我们还在三文鱼染色体上发现了一个数量性状基因座（QTL）的区域，其中含有与斑点数量相关的基因。所以，基因的确起到了一定的作用，但与环境的影响相比，基因的影响微乎其微。
这些来自Guddal河的野生三文鱼和养殖三文鱼都只有少量斑点，尽管这些三文鱼在位于Matre的研究站的池塘中生活了两年。这说明三文鱼在幼鲑时期从河流中转移前就已长出斑点。三文鱼离开河流环境前就长出了不同的斑点，这一现象非常重要。
目前，清理河流里逃走的养殖三文鱼都是通过一些明显的特征如身体形状、鳍的磨损和斑点。如果养殖三文鱼在自然中长期生存，就会变得像野生三文鱼。
几项研究表明，三文鱼上的斑点随着时间的推移仍保持稳定，所以它们在逃走后可能不会消失，尽管我们并未对此进行验证。但是对于在河里捕捉到的三文鱼，其身上斑点较多仍可作为它是逃走的养殖三文鱼的可靠标识。
最近，在斑马鱼中进行的实验表明，当其条纹在实验中被破坏后，重新长出条纹的方式符合艾伦图灵的生物模式形成理论。图灵模式认为环境可以影响生物模式，并产生个体特征，例如人类指纹。在大西洋三文鱼等被充分研究的物种中发现环境决定模式，为研究生物模式形成提供了新的契机。
模式的个性特征和斑点长期的稳定性也表明斑点模式可以用于通过视频监控来识别鱼类个体，而这可以用于监测养殖场和河流中的环境。
摘要：
Background
In fish, morphological colour changes occur from variations in pigment concentrations and in the morphology, density, and distribution of chromatophores in the skin. However, the underlying mechanisms remain unresolved in most species. Here, we describe the first investigation into the genetic and environmental basis of spot pattern development in one of the world’s most studied fishes, the Atlantic salmon. We reared 920 salmon from 64 families of domesticated, F1-hybrid and wild origin in two contrasting environments (Hatchery; tanks for the freshwater stage and sea cages for the marine stage, and River; a natural river for the freshwater stage and tanks for the marine stage). Fish were measured, photographed and spot patterns evaluated.
Results
In the Hatchery experiment, significant but modest differences in spot density were observed among domesticated, F1-hybrid (1.4-fold spottier than domesticated) and wild salmon (1.7-fold spottier than domesticated). A heritability of 6% was calculated for spot density, and a significant QTL on linkage group SSA014 was detected. In the River experiment, significant but modest differences in spot density were also observed among domesticated, F1-hybrid (1.2-fold spottier than domesticated) and wild salmon (1.8-fold spottier than domesticated). Domesticated salmon were sevenfold spottier in the Hatchery vs. River experiment. While different wild populations were used for the two experiments, on average, these were 6.2-fold spottier in the Hatchery vs. River experiment. Fish in the Hatchery experiment displayed scattered to random spot patterns while fish in the River experiment displayed clustered spot patterns.
Conclusions
These data demonstrate that while genetics plays an underlying role, environmental variation represents the primary determinant of spot pattern development in Atlantic salmon.
期刊介绍：BMC Ecologyis an open access, peer-reviewed journal that considers articles on environmental, behavioral and population ecology as well as biodiversity of plants, animals and microbes.
2016 Journal Metrics
Citation Impact
2.896 - 2-year Impact Factor
NA - 5-year Impact Factor
1.148 - Source Normalized Impact per Paper (SNIP)
