1.1.1 DIFFERENT SILK-PRODUCING GLANDS

There are at least seven different fiber types that can be spun from black widow spi­ders. Specialized abdominal silk-producing glands display distinct morphological

features and are responsible for manufacturing the different silk types.1 Each gland has evolved the ability to express different fibroins that can be spun into distinct fibers that perform specific biological tasks, including threads used for locomotion, prey wrapping, web construction, and protection of eggs (females), as well as re­production and adhesion of threads (Table 1.1).1 These glands, which are normally found in pairs in a single individual, include the major and minor ampullate, tubu — liform, flagelliform, aggregate, aciniform and pyriform. Because most laboratories across the world are focusing on elucidating the properties and characteristics of dragline silk, this review, in particular will emphasize the latest information on this fiber type and current progress made with synthetic silk fiber production using re­combinant dragline silk proteins.