Glow worm cave expedition
From June 25 to June 30 I conducted a ‘Silk Biology’ course at the Centro Universitario de Rivera, Rivera, Uruguay with Dr Luis Fernando Garcia, Dr Mariángeles Lacava, Prof Carmen Viera, and Dr Marco Benamú. We had nine students attend from different parts of Uruguay, as well as Argentina and Mexico. The week was intensive, for students and instructors, with a 3 hour lecture block scheduled on each of the six days and four hours of Practicals scheduled for four of the six days. The lectures were shared among myself (12 of 18 hours), Prof Viera (3 hours) and Dr Benamú (3 hours). Assessments included 4 short exams and Practical write ups. On the night of June 28 all participants attended the launch of the book Behavior and Ecology of Spider at Centro Universitario de Rivera.
Lectures comprised of (i) Silk background (silkmoths, Sericulture, myths, silk properties, future applications), (ii) Silk diversity (overview of invertebrates that produce silk, from velvet worms to spiders, and genetically engineered goats), (iii) Silk chemistry (amino acids/motifs and protein hierarchical structure, structure-function relationships in silk and other proteins, methods for analysis including X-ray scattering and NMR), (iv) Silk mechanics (mechanical properties, stress-strain dynamics, silk compared to other fibres, methods of analysis including tensile testing, AFM, and FEA), (v) Silk plasticity (environmental factors impacting fibrous and gluey silk performance such as diet, UV, wind, covering work in my lab and elsewhere), (vi) Silk gland physiology (comparative anatomy across silk producing invertebrates, different spider glands, how gland physiology affects silk properties), (vii) Silk synthetics (the applications of insect and spider silks in industry, review of biomimetics, cloning and genetic engineering), (viii) Discussion and feedback session (current and future projects, course evaluation). Prof Viera covered spider web diversity and Dr Benamú covered the effect of pesticides on insects, spiders and silks. The lectures were a mix of lecture material, demonstrations, outdoor activities and videos (e.g. the Silk Spinners from BBCs Life in the Undergrowth).
The Practicals were when the fun stuff, for both students and teachers, happened. We measured orb webs in the University garden to estimate architectural parameters such as web area, spiral thread length and mesh size. We collected spiral glues from orb webs, cribellate silks from the many cribellate spiders found, and gumfoot threads from the many Latrodectus geometricus on the University building and examined them under the microscope to estimates glue droplet volumes from simple measurements using Image J. At Parque de Osu we collected a wide range of spiders (including spiny spiders, Alpida sp., various wolf spiders, and an awesome tarantula, see photos). A sample was returned to the lab in Rivera and forcibly silked. One of the wolf spiders was sacrificed for dissection and the silk glands examined. We also dedicated a Practical to degumming silkworm cocoons to obtain single threads and we spun some rudimentary fibres by forcing Bovine Serum Albumin through a tapered tube via syringe, so as to very coarsely mimic a silk gland.
The feedback gained suggested the students had a good time gained a lot of useful skills and experiences. Importantly, several of them are now talking about instigating a silk focused graduate projects (e.g. projects on eggsacs and jumping spider silk are in the pipeline). This could be the first step toward expanding the silk program in Uruguay, or South America more broadly. We hope that the program can continue. Indeed, we are already planning the next course in Uruguay, and talking about expanding it into other parts of South America, perhaps Argentina, Columbia or Mexico?