Spider major ampullate (MA) silk, with its combination of strength and extensibility, outperforms any synthetic equivalents. There is thus much interest in understanding its underlying materiome. While the expression of the different silk proteins (spidroins) appears an integral component of silk performance, our understanding of the nature of the relationship between the spidroins, their constituent amino acids and MA silk mechanics is ambiguous. To provide clarity on these relationships across spider species, we performed a meta-analysis using phylogenetic comparative methods. These showed that glycine and proline, both of which are indicators of differential spidroin expression, had effects on MA silk mechanics across the phylogeny. We also found serine to correlate with silk mechanics, probably via its presence within the carboxyl and amino-terminal domains of the spidroins. From our analyses, we concluded that the spidroin expression shifts across the phylogeny from predominantly MaSp1 in the MA silks of ancestral spiders to predominantly MaSp2 in the more derived spiders' silks. This trend was accompanied by an enhanced ultimate strain and decreased Young's modulus in the silks. Our meta-analysis enabled us to decipher between real and apparent influences on MA silk properties, providing significant insights into spider silk and web coevolution and enhancing our capacity to create spider silk-like materials.

中文翻译：

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荟萃分析揭示了蜘蛛系统发育中大壶腹丝的物质组学关系


蜘蛛大壶腹 (MA) 丝兼具强度和延展性，优于任何合成同类产品。因此，人们对理解其底层物质组很感兴趣。虽然不同丝蛋白（蜘蛛丝蛋白）的表达似乎是丝性能不可或缺的组成部分，但我们对蜘蛛丝蛋白、其组成氨基酸和 MA 丝力学之间关系的本质的理解并不明确。为了清楚地了解蜘蛛物种之间的这些关系，我们使用系统发育比较方法进行了荟萃分析。这些结果表明，甘氨酸和脯氨酸（两者都是蜘蛛丝蛋白差异表达的指标）对整个系统发育的 MA 丝力学具有影响。我们还发现丝氨酸与丝力学相关，可能是通过丝氨酸存在于蛛丝蛋白的羧基和氨基末端结构域中。根据我们的分析，我们得出结论，蛛丝蛋白的表达在整个系统发育过程中发生了变化，从祖先蜘蛛的 MA 丝中主要为 MaSp1，到更衍生的蜘蛛丝中主要为 MaSp2。这种趋势伴随着丝的极限应变的增强和杨氏模量的降低。我们的荟萃分析使我们能够解读对 MA 丝特性的真实影响和明显影响，为蜘蛛丝和网的共同进化提供重要见解，并增强我们制造类蜘蛛丝材料的能力。