Changes in composition of spider orb web sticky droplets with starvation and web removal, and synthesis of sticky droplet compounds

摘要: The sticky spiral of araneoid spider orb webs consists silk fibers coated with adhesive droplets. droplets contain a variety low-molecular-mass compounds (LMM). Within species, fairly consistent ratio LMM is often observed, but substantial variability can exist. To gain insight into factors influencing composition, spiders three araneid species were starved and from their analyzed for changes in composition. determine if these the spider's ability to synthesize different organic LMM, synthetic capacities estimated following feeding radiolabeled metabolites. Some droplet composition broadly differing capacities: molar percentages less readily synthesized (e.g. choline, isethionate, N-acetyltaurine) typically declined starvation, at least during portion imposed fast, while more GABamide, glycine) tended increase. Most striking was apparent partial substitution N-acetylputrescine by GABamide fasting Argiope trifasciata. However, departures expected compositional shifts demonstrated that capacity alone does not adequately predict starvation. Moreover, controls exhibited some similar starving spiders. As both removed chemical analysis could be recycled, loss contained likely contributed similarities between treatments. In addition, molted, oviposited and/or built heavier webs. added metabolic demands activities may have those resulting