Spiders produce multiple silks with different physical properties that allow them to occupy a diverse range of ecological niches, including the underwater environment. Despite this functional diversity, past molecular analyses show a high degree of amino acid sequence similarity between C-terminal regions of silk genes that appear to be independent of the physical properties of the resulting silks; instead, this domain is crucial to the formation of silk fibers. Here, we present an analysis of the C-terminal domain of all known types of spider silk and include silk sequences from the spider Argyroneta aquatica, which spins the majority of its silk underwater. Our work indicates that spiders have retained a highly conserved mechanism of silk assembly, despite the extraordinary diversification of species, silk types and applications of silk over 350 million years. Sequence analysis of the silk C-terminal domain across the entire gene family shows the conservation of two uncommon amino acids that are implicated in the formation of a salt bridge, a functional bond essential to protein assembly. This conservation extends to the novel sequences isolated from A. aquatica. This finding is relevant to research regarding the artificial synthesis of spider silk, suggesting that synthesis of all silk types will be possible using a single process.

Biodiversity Lab Crop Research Institute Drnovská 507 16106 Prague 6 Ruzyně Czechia

Centre for Biomolecular Sciences School of Chemistry University of Nottingham Nottingham NG7 2RD UK

School of Life Sciences University of Nottingham Nottingham NG7 2RD UK

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Agnarsson I, Boutry C, Wong SC, Baji A, Dhinojwala A, Sensenig AT, et al. Supercontraction forces in spider dragline silk depend on hydration rate. Zoology. 2009;112:325–331. doi: 10.1016/j.zool.2008.11.003. PubMed DOI

Andersson M, Chen G, Otikovs M, Landreh M, Nordling K, Kronqvist N, et al. Carbonic anhydrase generates CO(2) and H(+) that drive Spider silk formation via opposite effects on the terminal domains. PLoS Biol. 2014;12(8):e1001921. doi: 10.1371/journal.pbio.1001921. PubMed DOI PMC

Andersson M, Jia Q, Abella A, Lee XY, Landreh M, Purhonen P, et al. Biomimetic spinning of artificial spider silk from a chimeric minispidroin. Nat Chem Biol. 2017;13:262–264. doi: 10.1038/nchembio.2269. PubMed DOI

Askarieh G, Hedhammar M, Nordling K, Saenz A, Casals C, Rising A, et al. Self-assembly of spider silk proteins is controlled by a pH-sensitive relay. Nature. 2010;465:236–238. doi: 10.1038/nature08962. PubMed DOI

Babb PL, Lahens NF, Correa-Garhwal SM, Nicholson DN, Kim EJ, Hogenesch JB, et al. The Nephila clavipes genome highlights the diversity of spider silk genes and their complex expression. Nat Genet. 2017;49:895–903. doi: 10.1038/ng.3852. PubMed DOI

Beckwitt R, Arcidiacono S. Sequence conservation in the C-terminal region of spider silk proteins (Spidroin) from Nephila clavipes (Tetragnathidae) and Araneus bicentenarius (Araneidae). J Biol Chem. 1994;269:6661–6663. PubMed

Blackledge TA, Boutry C, Wong SC, Baji A, Dhinojwala A, Sahni V. How super is supercontraction? Persistent versus cyclic responses to humidity in spider dragline silk. J Exp Biol. 2009;212:1981–1989. doi: 10.1242/jeb.028944. PubMed DOI

Blackledge TA, Hayashi CY. Silken toolkits: biomechanics of silk fibers spun by the orb web spider Argiope argentata (Fabricius 1775). J Exp Biol. 2006;209:2452–2461. doi: 10.1242/jeb.02275. PubMed DOI

Blamires SJ, Blackledge TA, Tso IM. Physicochemical property variation in spider silk: ecology, evolution, and synthetic production. Annu Rev Entomol. 2017;62:443–460. doi: 10.1146/annurev-ento-031616-035615. PubMed DOI

Boutry C, Blackledge TA. Evolution of supercontraction in spider silk: structure–function relationship from tarantulas to orb-weavers. J Exp Biol. 2010;213:3505–3514. doi: 10.1242/jeb.046110. PubMed DOI

Buffalo V (2014) Scythe—A Bayesian adapter trimmer (version 0.994 BETA) [Software]

Catalog WS (2016) World Spider Catalog, version 17

Challis RJ, Goodacre SL, Hewitt GM. Evolution of spider silks: conservation and diversification of the C-terminus. Insect Mol Biol. 2006;15:45–56. doi: 10.1111/j.1365-2583.2005.00606.x. PubMed DOI

Clarke TH, Garb JE, Haney RA, Chaw RC, Hayashi CY, Ayoub NA. Evolutionary shifts in gene expression decoupled from gene duplication across functionally distinct spider silk glands. Sci Rep. 2017;7:8393. doi: 10.1038/s41598-017-07388-1. PubMed DOI PMC

Clarke TH, Garb JE, Hayashi CY, Arensburger P, Ayoub NA. Spider transcriptomes identify ancient large-scale gene duplication event potentially important in silk gland evolution. Genome Biol Evol. 2015;7:1856–1870. doi: 10.1093/gbe/evv110. PubMed DOI PMC

Clerck CA (1757). Svenska Spindlar uti sina hufvud-slågter indelte samt under några och sextio särskildte arter beskrefne och med illuminerade figurer uplyste/Aranei Svecici, descriptionibus et figuris æneis illustrati, ad genera subalterna redacti, speciebus ultra LX determinati

Coddington JA (2005) Phylogeny and classification of spiders. In: Ubick D, Paquin P, Cushing PE, & Roth V (eds) Spiders of North America: an identification manual. American Arachnological Society, Poughkeepsie, New York, USA

Collin MA, Clarke TH, Ayoub NA, Hayashi CY. Evidence from multiple species that spider silk glue component ASG2 is a spidroin. Sci Rep. 2016;6:21589. doi: 10.1038/srep21589. PubMed DOI PMC

Drozdetskiy A, Cole C, Procter J, Barton GJ. JPred4: a protein secondary structure prediction server. Nucleic Acids Res. 2015;43:W389–W394. doi: 10.1093/nar/gkv332. PubMed DOI PMC

Eisoldt L, Smith A, Scheibel T. Decoding the secrets of spider silk. Mater Today. 2011;14:80–86. doi: 10.1016/S1369-7021(11)70057-8. DOI

Garb JE. Spider silk: an ancient biomaterial for the 21st century. In: Penney D, editor. Spider research in the 21st century: trends and perspectives. Manchester: Siri Scientific Press; 2013. pp. 252–281.

Garb JE, Ayoub NA, Hayashi CY. Untangling spider silk evolution with spidroin terminal domains. BMC Evolut Biol. 2010;10:243. doi: 10.1186/1471-2148-10-243. PubMed DOI PMC

Gnesa E, Hsia Y, Yarger JL, Weber W, Lin-Cereghino J, Lin-Cereghino G. Conserved C-terminal domain of spider tubuliform spidroin 1 contributes to extensibility in synthetic fibers. Biomacromolecules. 2012;13:304–312. doi: 10.1021/bm201262n. PubMed DOI

Grabherr MG, Haas BJ, Yassour M, Levin JZ, Thompson DA, Amit I. Full-length transcriptome assembly from RNA-Seq data without a reference genome. Nat Biotechnol. 2011;29:644–652. doi: 10.1038/nbt.1883. PubMed DOI PMC

Haas BJ, Papanicolaou A, Yassour M, Grabherr M, Blood PD, Bowden J et al. (2013) De novo transcript sequence reconstruction from RNA-Seq: reference generation and analysis with Trinity. Nat Protocols 8(8): 10.1038/nprot.2013.084 PubMed PMC

Hagn F, Eisoldt L, Hardy JG, Vendrely C, Coles M, Scheibel T. A conserved spider silk domain acts as a molecular switch that controls fibre assembly. Nature. 2010;465:239–242. doi: 10.1038/nature08936. PubMed DOI

Harvey D, Bardelang P, Goodacre SL, Cockayne A, Thomas NR (2017). Antibiotic spider silk: site-specific functionalization of recombinant spider silk using “Click” chemistry. Adv Mater 29:1604245-n/a. PubMed

Hayashi CY, Lewis RV. Evidence from flagelliform silk cDNA for the structural basis of elasticity and modular nature of spider silks1. J Mol Biol. 1998;275:773–784. doi: 10.1006/jmbi.1997.1478. PubMed DOI

Hayashi CY, Shipley NH, Lewis RV. Hypotheses that correlate the sequence, structure, and mechanical properties of spider silk proteins. Int J Biol Macromol. 1999;24:271–275. doi: 10.1016/S0141-8130(98)00089-0. PubMed DOI

Hinman MB, Jones JA, Lewis RV. Synthetic spider silk: a modular fiber. Trends Biotechnol. 2000;18:374–379. doi: 10.1016/S0167-7799(00)01481-5. PubMed DOI

Hormiga G, Griswold CE. Systematics, phylogeny, and evolution of Orb-weaving spiders. Annu Rev Entomol. 2014;59:487–512. doi: 10.1146/annurev-ento-011613-162046. PubMed DOI

Ittah S, Cohen S, Garty S, Cohn D, Gat U. An essential role for the C-terminal domain of A dragline spider silk protein in directing fiber formation. Biomacromolecules. 2006;7:1790–1795. doi: 10.1021/bm060120k. PubMed DOI

Ittah S, Michaeli A, Goldblum A, Gat U. A model for the structure of the C-terminal domain of dragline spider silk and the role of its conserved cysteine. Biomacromolecules. 2007;8:2768–2773. doi: 10.1021/bm7004559. PubMed DOI

Joshi N, Fass J (2011). Sickle: a sliding-window, adaptive, quality-based trimming tool for FastQ files (Version1.33) [Software]

Kearse M, Moir R, Wilson A, Stones-Havas S, Cheung M, Sturrock S. Geneious basic: an integrated and extendable desktop software platform for the organization and analysis of sequence data. Bioinformatics. 2012;28:1647–1649. doi: 10.1093/bioinformatics/bts199. PubMed DOI PMC

Larkin MA, Blackshields G, Brown NP, Chenna R, McGettigan PA, McWilliam H. Clustal W and Clustal X version 2A0. Bioinformatics. 2007;23:2947–2948. doi: 10.1093/bioinformatics/btm404. PubMed DOI

Motriuk-Smith D, Smith A, Hayashi CY, Lewis RV. Analysis of the conserved N-terminal domains in major ampullate spider silk proteins. Biomacromolecules. 2005;6:3152–3159. doi: 10.1021/bm050472b. PubMed DOI

Nentwig W, Arnedo MA, Coddington JA, Hormiga G, Jocqué R, Kropf C, et al. Appendix. Spider Phylogeny. In: Nentwig W, et al., editors. Spider ecophysiology. Berlin: Springer; 2013.

Perez-Rigueiro J, Plaza GR, Torres FG, Hijar A, Hayashi C, Perea GB. Supercontraction of dragline silk spun by lynx spiders aOxyopidaea. Int J Biol Macromol. 2010;46:555–557. doi: 10.1016/j.ijbiomac.2010.03.013. PubMed DOI

Rising A, Hjalm G, Engstrom W, Johansson J. N-terminal nonrepetitive domain common to dragline, flagelliform, and cylindriform spider silk proteins. Biomacromolecules. 2006;7:3120–3124. doi: 10.1021/bm060693x. PubMed DOI

Rising A, Johansson J. Toward spinning artificial spider silk. Nat Chem Biol. 2015;11:309–315. doi: 10.1038/nchembio.1789. PubMed DOI

Rising A, Johansson J, Larson G, Bongcam-Rudloff E, Engström W, Hjälm G. Major ampullate spidroins from Euprosthenops australis: multiplicity at protein, mRNA and gene levels. Insect Mol Biol. 2007;16:551–561. PubMed

Sanggaard KW, Bechsgaard JS, Fang X, Duan J, Dyrlund TF, Gupta V. Spider genomes provide insight into composition and evolution of venom and silk. Nat Commun. 2014;5:3765. PubMed PMC

Schütz D, Taborsky M. Adaptations to an aquatic life may be responsible for the reversed sexual size dimorphism in the water spider, Argyroneta aquatica. Evolut Ecol Res. 2003;5:105–117.

Schütz D, Taborsky M. Mate choice and sexual conflict in the size dimorphic water spider, Argyroneta aquatica (araneae, argyronetidae). J Arachnol. 2005;33:767–775. doi: 10.1636/S03-56.1. DOI

Schütz D, Taborsky M. Sexual selection in the water spider: female choice and male-male competition. Ethology. 2011;117:1101–1110. doi: 10.1111/j.1439-0310.2011.01965.x. DOI

Schutz D, Taborsky M, Drapela T. Air bells of water spiders are an extended phenotype modified in response to gas composition. J Exp Zool Part A. 2007;307:549–555. doi: 10.1002/jez.410. PubMed DOI

Seymour RS, Hetz SK. The diving bell and the spider: the physical gill of Argyroneta aquatica. J Exp Biol. 2011;214:2175–2181. doi: 10.1242/jeb.056093. PubMed DOI

Sponner A, Unger E, Grosse F, Weisshart K. Conserved C-termini of Spidroins are secreted by the major ampullate glands and retained in the silk thread. Biomacromolecules. 2004;5:840–845. doi: 10.1021/bm034378b. PubMed DOI

Sponner A, Unger E, Grosse F, Weisshart K. Conserved C-termini of spidroins are secreted by the major ampullate glands and retained in the silk thread. Biomacromolecules. 2004;5:840–845. doi: 10.1021/bm034378b. PubMed DOI

Sponner A, Vater W, Rommerskirch W, Vollrath F, Unger E, Grosse F, et al. The conserved C-termini contribute to the properties of spider silk fibroins. Biochem Biophys Res Commun. 2005;338:897–902. doi: 10.1016/j.bbrc.2005.10.048. PubMed DOI

Stark M, Grip S, Rising A, Hedhammar M, Engström W, Hjälm G, et al. Macroscopic fibers self-assembled from recombinant miniature spider silk proteins. Biomacromolecules. 2007;8:1695–1701. doi: 10.1021/bm070049y. PubMed DOI

Tamura K, Stecher G, Peterson D, Filipski A, Kumar S. MEGA6: molecular evolutionary genetics analysis version 6.0. Mol Biol Evol. 2013;30:2725–2729. doi: 10.1093/molbev/mst197. PubMed DOI PMC

Vollrath F, Knight DP. Liquid crystalline spinning of spider silk. Nature. 2001;410:541–548. doi: 10.1038/35069000. PubMed DOI

From fibres to adhesives: evolution of spider capture threads from web anchors by radical changes in silk gland function