SILK PRODUCTION IN A SPIDER INVOLVES ACID BATH TREATMENT

We studied physiological conditions during the spinning of dragline si lk by the garden cross spider, Araneus diadematus. Silk is converted f rom the liquid feedstock in the gland into a solid thread via a taperi ng tubular duct and exits at a spigot. The distal part of the tubule a ppears specialized for ion transport and the management of the pH insi de the lumen. Thus, it appears that spider silk in viva, like some ind ustrial polymers in vitro, is spun through an acid bath.