Spider silk colour co-varies with thermal properties but not protein structure

Understanding how and why animal secretions vary in property has important biomimetic implications as desirable properties might co-vary. Spider major ampullate (MA) silk, for instance, is a secretion earmarked for biomimetic applications, but many of its properties vary among and between species across environments. Here we tested the hypothesis that MA silk colour, protein structure, and thermal properties co-vary when protein uptake is manipulated in the spider Trichonephila plumipes. We collected silk from adult female spiders maintained on a protein fed or protein deprived diet. Based on spectrophotometric quantifications we classified half the silks as ‘bee visible’ and the other half ‘bee invisible’. Wide Angle X-ray Scattering and Differential Scanning Calorimetry were then used to assess the silk’s protein structure, and thermal properties respectively. We found that although protein structures and thermal properties varied across our treatments only the thermal properties co-v...探究动物分泌物的性状如何变化、为何变化，具有重要的仿生学意义，因为理想的性状往往存在共变关联。例如，蜘蛛的大壶状腺丝（major ampullate silk, MA）是一类极具仿生应用潜力的分泌产物，但其性状在不同环境下的物种间乃至同物种内均存在显著差异。本研究以斑络新妇（Trichonephila plumipes）为实验对象，通过调控其蛋白质摄入量，验证了“大壶状腺丝的颜色、蛋白质结构与热性状存在共变关系”这一假说。我们收集了饲喂高蛋白饲料与蛋白质剥夺饲料的成年雌性蜘蛛所产出的蛛丝；通过分光光度定量分析，将半数蛛丝归类为“蜜蜂可见”型，其余半数归类为“蜜蜂不可见”型。随后分别采用广角X射线散射（Wide Angle X-ray Scattering, WAXS）与差示扫描量热法（Differential Scanning Calorimetry, DSC）对蛛丝的蛋白质结构与热性状进行表征。研究结果显示，尽管不同饲喂处理组的蛛丝蛋白质结构与热性状均存在变异，但仅热性状存在共变……