A small addition to the silk recipe
The researchers compared gene expression across spider silk glands and identified recently evolved genes associated with silk production. One of them, SpiCE-DS8, encodes a 67-amino-acid secretory peptide found in the sampled Nephilinae lineage.
Proteomic and interaction experiments placed the peptide in the dragline-silk system and showed that it interacts with the N-terminal region of a major ampullate spidroin. The team proposed that this interaction helps silk proteins move from a soluble state toward an ordered solid fibre.
Testing the mechanical effect
In laboratory wet-spinning tests, the conserved peptide region increased beta-sheet content and improved the strength, extensibility, or toughness of the experimental fibres, depending on the mixture. These were manufactured fibres made with silkworm fibroin or spidroin-expressing silkworm material, not intact natural webs.
Why the distinction matters
The work complements research on the nanoscale packing of natural silk. It suggests that both fibre architecture and small accessory molecules can matter, while further work is needed to measure the peptide’s contribution inside living spiders and across other lineages.