Spider silk is Nature’s high performance material that has the potential to revolutionize the materials industry. However, production and spinning of artificial spider silk fibers are very challenging, due to the large size and repetitive nature of the silk proteins. In order to fulfill the potential of spider silk we need to increase our understanding of the silk formation process. The only so far characterized spider genome from Nephila clavipes is large (3.5Gb) and repetitive 55%) which have made the characterization difficult (Babb et al. Nat genetics. 2017). However, the 3’UTRs are annotated which opens up the possibility for using scRNA sequencing of the Nephila glands. For artificial spider silk production, the spider silk genes are of particular interest, and also these poses additional challenges in that they are large (up to 30kb), extremely repetitive and GC-rich. These are probably the reasons why the spider silk genes in the Nephila genome could not be completely characterized.
Recent insights into the physiology and molecular mechanisms of the spinning process has made it to develop a miniature spider silk protein that can be spun into fibers using a biomimetic artificial spider silk spinning device (see our publications Andersson et al. Nat Chem Biol. 2017; Otikovs et al. Angew Chemie Int Engl Ed. 2017). We are, for the first time, able to spin artificial silk fibers in which the proteins adopt correct secondary, tertiary and quaternary structures. The fibers we produce are not as strong as the native material which may be a consequence of proteins missing in the fiber and/or that the spinning conditions are suboptimal.
Now, we aim to build on these recent insights and aim to generate artificial silk fibers with the same mechanical properties as native spider silk. To reach this aim we will use single cell RNA (ScRNA) to better understand the function of the spider silk gland, and possibly also identify novel proteins involved in the spinning process.