Chipman, Ariel D.2; Ferrier, David E.K.3; Brena, Carlo9; Qu, Jiaxin5; Hughes, Daniel S.T.6; Schröder, Reinhard7; Torres-Oliva, Montserrat9; Znassi, Nadia9; Jiang, Huaiyang8; Almeida, Francisca C8; Alonso, Claudio R8; Apostolou, Zivkos8; Aqrawi, Peshtewani8; Arthur, Wallace8; Barna, Jennifer C J8; Blankenburg, Kerstin P8; Brites, Daniela8; Capella-Gutiérrez, Salvador8; Coyle, Marcus8; Dearden, Peter K8; Du Pasquier, Louis8; Duncan, Elizabeth J8; Ebert, Dieter8; Eibner, Cornelius8; Erikson, Galina8; Evans, Peter D8; Extavour, Cassandra G8; Francisco, Liezl8; Gabaldón, Toni8; Gillis, William J8; Goodwin-Horn, Elizabeth A8; Green, Jack E8; Griffiths-Jones, Sam8; Grimmelikhuijzen, Cornelis10; Gubbala, Sai8; Guigó, Roderic8; Han, Yi8; Hauser, Frank10; Havlak, Paul8; Hayden, Luke8; Helbing, Sophie8; Holder, Michael8; Hui, Jerome H L8; Hunn, Julia P8; Hunnekuhl, Vera S8; Jackson, LaRonda8; Javaid, Mehwish8; Jhangiani, Shalini N8; Jiggins, Francis M8; Jones, Tamsin E8; Kaiser, Tobias S8; Kalra, Divya8; Kenny, Nathan J8; Korchina, Viktoriya8; Kovar, Christie L8; Kraus, F Bernhard8; Lapraz, François8; Lee, Sandra L8; Lv, Jie8; Mandapat, Christigale8; Manning, Gerard8; Mariotti, Marco8; Mata, Robert8; Mathew, Tittu8; Neumann, Tobias8; Newsham, Irene8; Ngo, Dinh N8; Ninova, Maria8; Okwuonu, Geoffrey8; Ongeri, Fiona8; Palmer, William J8; Patil, Shobha8; Patraquim, Pedro8; Pham, Christopher8; Pu, Ling-Ling8; Putman, Nicholas H8; Rabouille, Catherine8; Ramos, Olivia Mendivil8; Rhodes, Adelaide C8; Robertson, Helen E8; Robertson, Hugh M8; Ronshaugen, Matthew8; Rozas, Julio8; Saada, Nehad8; Sánchez-Gracia, Alejandro8; Scherer, Steven E8; Schurko, Andrew M8; Siggens, Kenneth W8; Simmons, DeNard8; Stief, Anna8; Stolle, Eckart8; Telford, Maximilian J8; Tessmar-Raible, Kristin8; Thornton, Rebecca8; van der Zee, Maurijn8; von Haeseler, Arndt8; Williams, James M8; Willis, Judith H8; Wu, Yuanqing8; Zou, Xiaoyan8; Lawson, Daniel8; Muzny, Donna M8; Worley, Kim C8; Gibbs, Richard A8; Akam, Michael8; Richards, Stephen8
1 Cell Biology and Neurobiology, Department of Biology, Faculty of Science, Københavns Universitet2 The Hebrew University of Jerusalem3 University of St. Andrews4 University of Cambridge5 Baylor College of Medicine6 EMBL - European Bioinformatics Institute7 Universität Rostock8 unknown9 University of Cambridge10 Cell Biology and Neurobiology, Department of Biology, Faculty of Science, Københavns Universitet
Myriapods (e.g., centipedes and millipedes) display a simple homonomous body plan relative to other arthropods. All members of the class are terrestrial, but they attained terrestriality independently of insects. Myriapoda is the only arthropod class not represented by a sequenced genome. We present an analysis of the genome of the centipede Strigamia maritima. It retains a compact genome that has undergone less gene loss and shuffling than previously sequenced arthropods, and many orthologues of genes conserved from the bilaterian ancestor that have been lost in insects. Our analysis locates many genes in conserved macro-synteny contexts, and many small-scale examples of gene clustering. We describe several examples where S. maritima shows different solutions from insects to similar problems. The insect olfactory receptor gene family is absent from S. maritima, and olfaction in air is likely effected by expansion of other receptor gene families. For some genes S. maritima has evolved paralogues to generate coding sequence diversity, where insects use alternate splicing. This is most striking for the Dscam gene, which in Drosophila generates more than 100,000 alternate splice forms, but in S. maritima is encoded by over 100 paralogues. We see an intriguing linkage between the absence of any known photosensory proteins in a blind organism and the additional absence of canonical circadian clock genes. The phylogenetic position of myriapods allows us to identify where in arthropod phylogeny several particular molecular mechanisms and traits emerged. For example, we conclude that juvenile hormone signalling evolved with the emergence of the exoskeleton in the arthropods and that RR-1 containing cuticle proteins evolved in the lineage leading to Mandibulata. We also identify when various gene expansions and losses occurred. The genome of S. maritima offers us a unique glimpse into the ancestral arthropod genome, while also displaying many adaptations to its specific life history.