TY - JOUR A1 - Chipman, Ariel D. A1 - Ferrier, David E. K. A1 - Brena, Carlo A1 - Qu, Jiaxin A1 - Hughes, Daniel S. T. A1 - Schroeder, Reinhard A1 - Torres-Oliva, Montserrat A1 - Znassi, Nadia A1 - Jiang, Huaiyang A1 - Almeida, Francisca C. A1 - Alonso, Claudio R. A1 - Apostolou, Zivkos A1 - Aqrawi, Peshtewani A1 - Arthur, Wallace A1 - Barna, Jennifer C. J. A1 - Blankenburg, Kerstin P. A1 - Brites, Daniela A1 - Capella-Gutierrez, Salvador A1 - Coyle, Marcus A1 - Dearden, Peter K. A1 - Du Pasquier, Louis A1 - Duncan, Elizabeth J. A1 - Ebert, Dieter A1 - Eibner, Cornelius A1 - Erikson, Galina A1 - Evans, Peter D. A1 - Extavour, Cassandra G. A1 - Francisco, Liezl A1 - Gabaldon, Toni A1 - Gillis, William J. A1 - Goodwin-Horn, Elizabeth A. A1 - Green, Jack E. A1 - Griffiths-Jones, Sam A1 - Grimmelikhuijzen, Cornelis J. P. A1 - Gubbala, Sai A1 - Guigo, Roderic A1 - Han, Yi A1 - Hauser, Frank A1 - Havlak, Paul A1 - Hayden, Luke A1 - Helbing, Sophie A1 - Holder, Michael A1 - Hui, Jerome H. L. A1 - Hunn, Julia P. A1 - Hunnekuhl, Vera S. A1 - Jackson, LaRonda A1 - Javaid, Mehwish A1 - Jhangiani, Shalini N. A1 - Jiggins, Francis M. A1 - Jones, Tamsin E. A1 - Kaiser, Tobias S. A1 - Kalra, Divya A1 - Kenny, Nathan J. A1 - Korchina, Viktoriya A1 - Kovar, Christie L. A1 - Kraus, F. Bernhard A1 - Lapraz, Francois A1 - Lee, Sandra L. A1 - Lv, Jie A1 - Mandapat, Christigale A1 - Manning, Gerard A1 - Mariotti, Marco A1 - Mata, Robert A1 - Mathew, Tittu A1 - Neumann, Tobias A1 - Newsham, Irene A1 - Ngo, Dinh N. A1 - Ninova, Maria A1 - Okwuonu, Geoffrey A1 - Ongeri, Fiona A1 - Palmer, William J. A1 - Patil, Shobha A1 - Patraquim, Pedro A1 - Pham, Christopher A1 - Pu, Ling-Ling A1 - Putman, Nicholas H. A1 - Rabouille, Catherine A1 - Ramos, Olivia Mendivil A1 - Rhodes, Adelaide C. A1 - Robertson, Helen E. A1 - Robertson, Hugh M. A1 - Ronshaugen, Matthew A1 - Rozas, Julio A1 - Saada, Nehad A1 - Sanchez-Gracia, Alejandro A1 - Scherer, Steven E. A1 - Schurko, Andrew M. A1 - Siggens, Kenneth W. A1 - Simmons, DeNard A1 - Stief, Anna A1 - Stolle, Eckart A1 - Telford, Maximilian J. A1 - Tessmar-Raible, Kristin A1 - Thornton, Rebecca A1 - van der Zee, Maurijn A1 - von Haeseler, Arndt A1 - Williams, James M. A1 - Willis, Judith H. A1 - Wu, Yuanqing A1 - Zou, Xiaoyan A1 - Lawson, Daniel A1 - Muzny, Donna M. A1 - Worley, Kim C. A1 - Gibbs, Richard A. A1 - Akam, Michael A1 - Richards, Stephen T1 - The first myriapod genome sequence reveals conservative arthropod gene content and genome organisation in the centipede Strigamia maritima JF - PLoS biology N2 - 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. Y1 - 2014 U6 - https://doi.org/10.1371/journal.pbio.1002005 SN - 1545-7885 VL - 12 IS - 11 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Green, Luci M. A1 - Kliem, Bernhard A1 - Wallace, A. J. T1 - Photospheric flux cancellation and associated flux rope formation and eruption JF - Astronomy and astrophysics : an international weekly journal N2 - Aims. We study an evolving bipolar active region that exhibits flux cancellation at the internal polarity inversion line, the formation of a soft X-ray sigmoid along the inversion line and a coronal mass ejection. The aim is to investigate the quantity of flux cancellation that is involved in flux rope formation in the time period leading up to the eruption. Methods. The active region is studied using its extreme ultraviolet and soft X-ray emissions as it evolves from a sheared arcade to flux rope configuration. The evolution of the photospheric magnetic field is described and used to estimate how much flux is reconnected into the flux rope. Results. About one third of the active region flux cancels at the internal polarity inversion line in the 2.5 days leading up to the eruption. In this period, the coronal structure evolves from a weakly to a highly sheared arcade and then to a sigmoid that crosses the inversion line in the inverse direction. These properties suggest that a flux rope has formed prior to the eruption. The amount of cancellation implies that up to 60% of the active region flux could be in the body of the flux rope. We point out that only part of the cancellation contributes to the flux in the rope if the arcade is only weakly sheared, as in the first part of the evolution. This reduces the estimated flux in the rope to similar to 30% or less of the active region flux. We suggest that the remaining discrepancy between our estimate and the limiting value of similar to 10% of the active region flux, obtained previously by the flux rope insertion method, results from the incomplete coherence of the flux rope, due to nonuniform cancellation along the polarity inversion line. A hot linear feature is observed in the active region which rises as part of the eruption and then likely traces out the field lines close to the axis of the flux rope. The flux cancellation and changing magnetic connections at one end of this feature suggest that the flux rope reaches coherence by reconnection immediately before and early in the impulsive phase of the associated flare. The sigmoid is destroyed in the eruption but reforms quickly, with the amount of cancellation involved being much smaller than in the course of its original formation. KW - Sun: activity KW - Sun: coronal mass ejections (CMEs) KW - magnetic fields KW - magnetic reconnection KW - Sun: photosphere KW - Sun: magnetic topology Y1 - 2011 U6 - https://doi.org/10.1051/0004-6361/201015146 SN - 0004-6361 VL - 526 IS - 2 PB - EDP Sciences CY - Les Ulis ER -