Data from: Diet adaptation in dog reflects spread of prehistoric agriculture

Adaptations allowing dogs to thrive on a diet rich in starch, including a significant AMY2B copy number gain, constituted a crucial step in the evolution of the dog from the wolf. It is however not clear if this change was associated with the initial domestication or represents a secondary shift related to the subsequent development of agriculture. Previous efforts to study this process were based on geographically limited data sets and low-resolution methods and it is therefore not known to what extent the diet adaptations are universal among dogs and whether there are regional differences associated with alternative human subsistence strategies. Here we use droplet PCR to investigate worldwide AMY2B copy number diversity among indigenous as well as breed dogs and wolves to elucidate how a change in dog diet was associated with the domestication process and subsequent shifts in human subsistence. We find that AMY2B copy numbers are bimodally distributed with high copy numbers (median 2nAMY2B=11) in a majority of dogs but no, or few, duplications (median 2nAMY2B=3) in a small group of dogs originating mostly in Australia and the arctic. We show that this patterns correlates geographically to the spread of prehistoric agriculture and conclude that the diet change may not have been associated with initial domestication but rather the subsequent development and spread of agriculture to most, but not all regions of the globe.

使犬能够适应富含淀粉的饮食的适应性演化——其中包括AMY2B拷贝数的显著增加——是犬从狼演化而来的关键一步。然而目前尚不清楚这一变化是否与犬的初始驯化相关，还是属于与后续农业发展有关的次生转变。此前针对这一过程的研究均基于地理范围受限的数据集与低分辨率分析方法，因此目前仍不清楚这类饮食适应性在犬群中的普遍性程度，以及是否存在与不同人类生计策略相关的区域差异。本研究采用微滴PCR（droplet PCR）技术，对全球范围内的本土犬、品种犬以及狼的AMY2B拷贝数多样性进行检测，以阐明犬的饮食变化如何与驯化过程及后续人类生计策略转变相关联。研究结果显示，AMY2B拷贝数呈双峰分布：大多数犬的拷贝数较高（中位数2nAMY2B=11），而少数主要起源于澳大利亚与北极地区的犬群则无拷贝重复或仅存在少量重复（中位数2nAMY2B=3）。我们发现这一分布模式与史前农业的传播存在地理相关性，并由此得出结论：犬的饮食适应性变化或许并非与初始驯化相关，而是与后续农业的发展及向全球多数（而非全部）地区的传播有关。