cDNA Library Screening to Identify Novel Silk Genes for Potential Use in Spider Silk Production

The black widow spider produces silk threads that are a few micrometers in diameter but can be stronger by weight than high-tensile steel and elastic enough to stretch up to ten times their initial length. Future silk products for human applications include bulletproof vests, ropes and cords, and medical sutures. In order to identify new proteins involved in silk fibers, we screened a cDNA library prepared from silk-producing glands from the black widow spider. We hypothesized that cDNA sequences found in higher copy numbers in our library likely code for important products involved in the spider silk pathway. In order to determine this, viruses carrying black widow spider cDNAs incorporated into their viral chromosomes were excised and analyzed by DNA sequencing. Over 50 different recombinant viruses were analyzed in this study. Plasmids carrying the spider cDNAs were excised from the viral chromosome with the assistance of a helper phage, ExAssist, and their products were transformed into bacteria. Recombinant plasmids from the fifty different excised products were amplified, subject to DNA restriction analysis to verify the presence of cDNA inserts, followed by examination of their nucleic acid sequences using DNA sequence analysis. Our results will be discussed after the sequences from the different clones are fully analyzed using bioinformatic approaches