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Updated: Mar 25, 2026

Microdissection of Black Widow Spider Silk-producing Glands
Published on: January 11, 2011
Evidence from Multiple Species that Spider Silk Glue Component ASG2 is a Spidroin
Matthew A Collin1, Thomas H Clarke1,2, Nadia A Ayoub2
1University of California, Riverside, Department of Biology, Riverside, California 92521, United States.
Abstract:
Spiders in the superfamily Araneoidea produce viscous glue from aggregate silk glands. Aggregate glue coats prey-capture threads and hampers the escape of prey from webs, thereby increasing the foraging success of spiders. cDNAs for Aggregate Spider Glue 1 (ASG1) and 2 (ASG2) have been previously described from the golden orb-weaver, Nephila clavipes, and Western black widow, Latrodectus hesperus. To further investigate aggregate glues, we assembled ASG1 and ASG2 from genomic target capture libraries constructed from three species of cob-web weavers and three species of orb-web weavers, all araneoids. We show that ASG1 is unlikely to be a glue, but rather is part of a widespread arthropod gene family, the peritrophic matrix proteins. For ASG2, we demonstrate its remarkable architectural and sequence similarities to spider silk fibroins, indicating that ASG2 is a member of the spidroin gene family. Thus, spidroins have diversified into glues in addition to task-specific, high performance fibers.
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