Notes on Spider Silk Production and Genetic Engineering

Introduction to Spider Silk

• Spider silk is a strong fiber, stronger than steel for its weight.
• Traditional silk production (like from silkworms) is easy; silkworms work in groups and can be fed easily.
• Spiders are territorial and cannibalistic, making them difficult to farm in groups.

Crossing Spiders with Goats

• Dr. Jeffrey Turner has introduced a spider silk gene into goats to produce silk.
• Location: Farm outside Montreal, Canada.
• Genetic Engineering Process:
  • The spider silk gene is inserted into a fertilized goat egg using a fine glass pipette.
  • This gene integrates into one of the goat's chromosomes.
  • Result: The goats produce silk protein similar to a spider's dragline silk.

Characteristics of Dragline Silk

• Dragline silk is the strongest natural fiber known to science.
• It is used by spiders to create radial lines of webs and serves as a lifeline.

Obtaining Silk Protein from Goats

• Milking the goats produces milk containing spider silk protein due to the integrated gene.
• The silk protein is then refined from the milk into a syrupy material called spindle.

Fiber Production Process

• The challenge lies in creating a super strong fiber from the silk protein (spindle).
• Biomimicry in Fiber Formation:
  • Spiders form silk by expelling a protein solution through spinnerets, where the proteins align and crystallize.
  • Man-made spinnerets replicate this process to create continuous filaments.
• Current technology can only produce filaments one-tenth the strength of natural spider silk.

Conclusion

• Spiders have been producing silk for 450 million years, while human efforts are relatively new (10-15 years).
• The goal is to improve the technology to match or exceed the strength of natural spider silk.