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 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 utilizing 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 spidroin expression shifts across the phylogeny from predominantly MaSp1 in the MA silks of ancestral spiders to predominantly MaSp2 in the more derived spider’s 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 co-evolution and enhancing our capacity to create spider silk-like materials.

Data was collecting using the PRISMA guidelines across Scopus and Web of science with the key (i) Spider silk, (ii) Amino acid, (iii) Protein, (iv) Composition, (v) Mechanical and (vi) Properties.

There are missing values in the data set.

no= number of individuals