Molecular atlas of spider silk production could help bring unparalleled material to market

Researchers from Southwest University in China constructed the entire chromosome-scale genome assembly and complete spidroin gene set of the golden orb-weaving spider, Trichonephila clavata, known for its particularly strong, golden webs.

They confirm that their work “Provides multidimensional data that significantly expands knowledge of spider silk production…” and the researchers plan to use this new “molecular atlas” to better understand how spiders make their silk.

Published in the journal Nature communicationsthe paper details the steps the researchers took, from wild spider capture to polyomic analysis, to reveal gene interaction in the spider’s master gland, the gland responsible for producing dragline silk.

Spider dragline silk is a true wonder material with many potential medical and industrial applications. It is lighter and stronger than steel, while maintaining an elastic stretchability that rivals rubber. Unlike many synthetic materials, spider silk is non-toxic, biodegradable and biocompatible, making it an ideal material for surgical implants, biosensors and tissue reconstruction.

The only limitation to adopting spider silk as a replacement for a long list of materials we currently use is how difficult it is to manufacture. There was an attempt in the past to produce the proteins in goat milk by a company called Nexia, and it worked, but not on the scale needed for mass production.

And despite the obvious advantages of spider silk, no one has stepped forward to start spider farming on the scale required. The researchers expect that by better understanding silk production at the molecular level in spiders, they will gain practical knowledge that will help bring this unique material to market.

Construction of a molecular atlas with polyomics

To acquire the genome, the research team used the Oxford Nanopore platform, which can produce the most extended contiguous reads of any gene sequencer, as well as Illumina sequencing machines for more accurate but shorter read capture lengths and Hi-C for mapping chromosomes. By combining these three different sets of genomic data, the researchers were able to bioinformatically reconstruct a detailed model of the spider genome assembly at the chromosomal scale and the complete spidroin gene set.

Having this genomic data allows connections to be made between gene expression and ultimately the proteins found in the spider’s silk, which is exactly what the researchers did next. The team performed transcriptome (messenger RNA), protein and metabolite (signaling molecule) analysis of the three parts of the main ampulla gland. the tail, the sac and the pore.

Liquid chromatography-mass spectrometry analysis identified 28 proteins: 10 were spindroins, the proteins that make up spider silk, 15 were elements that make up spider silk, and one was associated with venom. By identifying the principal components, researchers could rank them in order of absolute quantification based on intensity.

Further analysis allowed them to characterize the specific biological functions of the tail, sac, and duct associated with silk production based on the function of genes and gene products. The ohmic tails mostly revolved around organic acid synthesis, those in Sac mainly focused on lipid production, and the channel ohmics were related to ion exchange and chitin synthesis.

Previous research had found some of the elements discovered in the current study, but none put the whole picture together in such a complete and comprehensive way.

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