Facial shape differences between rats selected for tame and aggressive behaviors
Facial shape differences between rats selected for tame and aggressive behaviors
复制标题
选择具有驯服和攻击行为的大鼠之间的面部形状差异
作者：
Nandini Singh;F. W. Albert;I. Plyusnina;L. Trut;Svante Pӓӓbo;K. Harvati
驯化一直伴随着一系列被称为驯化综合症的特征。这些包括温顺性增加，皮毛颜色改变，幼年行为延长，肾上腺功能改变和颅面尺寸缩小。Wilkins等人最近提出，包含驯化综合征的潜在特征的机制因素是神经嵴细胞（NCC）发育的改变。NCC形成了大量组织类型的前体，包括色素细胞、肾上腺、牙齿和面部骨骼。NCC发育缺陷可以解释驯化综合症的假设部分是基于德米特里·别利亚耶夫最初在银狐身上进行的驯化实验的结果。经过几代的驯化选择，狐狸表现出在驯化物种中观察到的表型。Belyaev还选择了一群老鼠，经过64代的选择，它们要么温顺，要么对人类具有防御性攻击。在这里，我们将重点放在Belyaev驯化的大鼠的面部形态上，以测试：1)老鼠的驯化是否会导致与狐狸相似的颅面变化；2)温顺大鼠和攻击性大鼠的面部形状，即ncc衍生区域是不同的。我们使用计算机断层扫描大鼠头骨和基于地标的几何形态计量学来量化和分析面部骨骼。我们发现，驯服和攻击性大鼠之间的面部形状差异与体型无关，这反映了家养动物与野生动物相比的变化。然而，没有证据表明，面对驯服的老鼠，性别二态性减少了。这表明，并非所有大鼠ncc衍生区域的形态变化都遵循家养动物或银狐中报道的形状变化模式。因此，作为驯化综合征一部分的某些表型趋势可能并不一致地存在于所有实验动物模型中。
Domestication has been consistently accompanied by a suite of traits called the domestication syndrome. These include increased docility, changes in coat coloration, prolonged juvenile behaviors, modified function of adrenal glands and reduced craniofacial dimensions. Wilkins et al recently proposed that the mechanistic factor underlying traits that encompass the domestication syndrome was altered neural crest cell (NCC) development. NCC form the precursors to a large number of tissue types including pigment cells, adrenal glands, teeth and the bones of the face. The hypothesis that deficits in NCC development can account for the domestication syndrome was partly based on the outcomes of Dmitri Belyaev’s domestication experiments initially conducted on silver foxes. After generations of selecting for tameness, the foxes displayed phenotypes observed in domesticated species. Belyaev also had a colony of rats selected over 64 generations for either tameness or defensive aggression towards humans. Here we focus on the facial morphology of Belyaev’s tame, ‘domesticated’ rats to test whether: 1) tameness in rats causes craniofacial changes similar to those observed in the foxes; 2) facial shape, i.e. NCC-derived region, is distinct in the tame and aggressive rats. We used computed-tomography scans of rat skulls and landmark-based geometric morphometrics to quantify and analyze the facial skeleton. We found facial shape differences between the tame and aggressive rats that were independent of size and which mirrored changes seen in domesticated animals compared to their wild counterparts. However, there was no evidence of reduced sexual dimorphism in the face of the tame rats. This indicates that not all morphological changes in NCC-derived regions in the rats follow the pattern of shape change reported in domesticated animals or the silver foxes. Thus, certain phenotypic trends that are part of the domestication syndrome might not be consistently present in all experimental animal models.