Abstract
Characterized by distinctive evolutionary adaptations, spiders provide a comprehensive system for evolutionary and developmental studies of anatomical organs, including silk and venom production. Here we performed cDNA sequencing using massively parallel sequencers (454 GS-FLX Titanium) to generate ∼80,000 reads from the spinning gland of Actinopus spp. (infraorder: Mygalomorphae) and Gasteracantha cancriformis (infraorder: Araneomorphae, Orbiculariae clade). Actinopus spp. retains primitive characteristics on web usage and presents a single undifferentiated spinning gland while the orbiculariae spiders have seven differentiated spinning glands and complex patterns of web usage. MIRA, Celera Assembler and CAP3 software were used to cluster NGS reads for each spider. CAP3 unigenes passed through a pipeline for automatic annotation, classification by biological function, and comparative transcriptomics. Genes related to spider silks were manually curated and analyzed. Although a single spidroin gene family was found in Actinopus spp., a vast repertoire of specialized spider silk proteins was encountered in orbiculariae. Astacin-like metalloproteases (meprin subfamily) were shown to be some of the most sampled unigenes and duplicated gene families in G. cancriformis since its evolutionary split from mygalomorphs. Our results confirm that the evolution of the molecular repertoire of silk proteins was accompanied by the (i) anatomical differentiation of spinning glands and (ii) behavioral complexification in the web usage. Finally, a phylogenetic tree was constructed to cluster most of the known spidroins in gene clades. This is the first large-scale, multi-organism transcriptome for spider spinning glands and a first step into a broad understanding of spider web systems biology and evolution.
Highlights
IntroductionSpidroins (or spider fibroins) are proteins from spider silks that have been studied for over 50 years
Spidroins are proteins from spider silks that have been studied for over 50 years
Internal consistence metrics based on internal consistency index (ICI) index depicted from BLAST searches were taken on account to evaluate appropriate read to contig mapping
Summary
Spidroins (or spider fibroins) are proteins from spider silks that have been studied for over 50 years. With the advent of biotechnology, the search for spidroins is turning into a commercial venture, and researchers have predicted the transgenic expression of silk proteins known to be half as strong as steel, and slightly less flexible than nylon [3]. Their biotechnological potential are under extensive study and these proteins may be used in a number of industrial applications – such as the production of biomaterials, fibers and textiles, films and bioplastics, hydrogels, porous sponges, and microcapsules [4,5]. More than searching and evaluating the genetic repertoire expressed in these tissues we tried to make sense on the systems biology of spider webs, correlating the analysis of molecular data with the evolution of the spinning gland anatomy and the behavior of web usage in these organisms
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
