Spider silk is an amazing natural fiber. It has captivated scientists for decades due to its remarkable properties: it’s incredibly strong, elastic, lightweight, and biodegradable.
This unique combination of characteristics holds immense potential for new applications if we can understand and improve upon its natural qualities.
Manipulating spider silk production within a living spider has long been a hurdle, but new research by the University of Bayreuth is advancing this capability using gene-editing tools.
“We have demonstrated, for the first time worldwide, that CRISPR-Cas9 can be used to incorporate a desired sequence into spider silk proteins, thereby enabling the functionalisation of these silk fibres,” said Professor Dr. Thomas Scheibel, Chair of Biomaterials at the University of Bayreuth and senior author of the study.
Gene-editing the common house spider
CRISPR-Cas9, a revolutionary gene-editing tool, precisely targets and modifies DNA by cutting or inserting genes. This highly efficient molecular tool has seen widespread use across plants, animals, and even bacteria.
Despite its widespread impact across numerous biological fields, it had never been applied to spiders until now.
The team says that controlling spider silk production within living spiders is vital for understanding the dragline thread’s structure. This structure is what gives dragline silk its extraordinary properties, like strength, elasticity, and toughness.
The insights could lead to the development of new silk functionalities for a wide range of applications, from advanced textiles and biomedical implants to specialized sensors and sustainable materials.
Professor Scheibel and his doctoral student Edgardo Santiago-Rivera accomplished a global first. The researchers chose the common house spider (Parasteatoda tepidariorum) for this experiment.
This new study involved the development of an injection solution with a gene-editing system and a red fluorescent protein gene sequence.
To perform the difficult microinjection, the researchers had to anesthetize the spiders using CO2 so they wouldn’t move.
Red fluorescence silk
The team injected this specially formulated solution into the eggs of unfertilized female spiders. These females were then mated with males of the same species.
The remarkable outcome was that the offspring from these gene-edited spiders displayed red fluorescence in their dragline silk. This glowing silk provided clear evidence that the desired gene sequence had been successfully “knocked in” (inserted) into a silk protein.
“The ability to apply CRISPR gene-editing to spider silk is very promising for materials science research – for example, it could be used to further increase the already high tensile strength of spider silk,” added Professor Scheibel.
This modified protein now stands as the blueprint. It demonstrates the feasibility of creating silk fibers with entirely new, engineered properties.
New Atlas reported that the research team also employed CRISPR-KO to investigate gene function in spiders. The researchers explored the impact of their modifications by inactivating a gene called “so.”
The CRISPR-KO technique confirmed that the “so” gene is important for spider eye development; blocking it resulted in eyeless spiders.
