@article{ChipmanFerrierBrenaetal.2014, author = {Chipman, Ariel D. and Ferrier, David E. K. and Brena, Carlo and Qu, Jiaxin and Hughes, Daniel S. T. and Schroeder, Reinhard and Torres-Oliva, Montserrat and Znassi, Nadia and Jiang, Huaiyang and Almeida, Francisca C. and Alonso, Claudio R. and Apostolou, Zivkos and Aqrawi, Peshtewani and Arthur, Wallace and Barna, Jennifer C. J. and Blankenburg, Kerstin P. and Brites, Daniela and Capella-Gutierrez, Salvador and Coyle, Marcus and Dearden, Peter K. and Du Pasquier, Louis and Duncan, Elizabeth J. and Ebert, Dieter and Eibner, Cornelius and Erikson, Galina and Evans, Peter D. and Extavour, Cassandra G. and Francisco, Liezl and Gabaldon, Toni and Gillis, William J. and Goodwin-Horn, Elizabeth A. and Green, Jack E. and Griffiths-Jones, Sam and Grimmelikhuijzen, Cornelis J. P. and Gubbala, Sai and Guigo, Roderic and Han, Yi and Hauser, Frank and Havlak, Paul and Hayden, Luke and Helbing, Sophie and Holder, Michael and Hui, Jerome H. L. and Hunn, Julia P. and Hunnekuhl, Vera S. and Jackson, LaRonda and Javaid, Mehwish and Jhangiani, Shalini N. and Jiggins, Francis M. and Jones, Tamsin E. and Kaiser, Tobias S. and Kalra, Divya and Kenny, Nathan J. and Korchina, Viktoriya and Kovar, Christie L. and Kraus, F. Bernhard and Lapraz, Francois and Lee, Sandra L. and Lv, Jie and Mandapat, Christigale and Manning, Gerard and Mariotti, Marco and Mata, Robert and Mathew, Tittu and Neumann, Tobias and Newsham, Irene and Ngo, Dinh N. and Ninova, Maria and Okwuonu, Geoffrey and Ongeri, Fiona and Palmer, William J. and Patil, Shobha and Patraquim, Pedro and Pham, Christopher and Pu, Ling-Ling and Putman, Nicholas H. and Rabouille, Catherine and Ramos, Olivia Mendivil and Rhodes, Adelaide C. and Robertson, Helen E. and Robertson, Hugh M. and Ronshaugen, Matthew and Rozas, Julio and Saada, Nehad and Sanchez-Gracia, Alejandro and Scherer, Steven E. and Schurko, Andrew M. and Siggens, Kenneth W. and Simmons, DeNard and Stief, Anna and Stolle, Eckart and Telford, Maximilian J. and Tessmar-Raible, Kristin and Thornton, Rebecca and van der Zee, Maurijn and von Haeseler, Arndt and Williams, James M. and Willis, Judith H. and Wu, Yuanqing and Zou, Xiaoyan and Lawson, Daniel and Muzny, Donna M. and Worley, Kim C. and Gibbs, Richard A. and Akam, Michael and Richards, Stephen}, title = {The first myriapod genome sequence reveals conservative arthropod gene content and genome organisation in the centipede Strigamia maritima}, series = {PLoS biology}, volume = {12}, journal = {PLoS biology}, number = {11}, publisher = {PLoS}, address = {San Fransisco}, issn = {1545-7885}, doi = {10.1371/journal.pbio.1002005}, pages = {24}, year = {2014}, abstract = {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.}, language = {en} } @article{GreenKliemWallace2011, author = {Green, Luci M. and Kliem, Bernhard and Wallace, A. J.}, title = {Photospheric flux cancellation and associated flux rope formation and eruption}, series = {Astronomy and astrophysics : an international weekly journal}, volume = {526}, journal = {Astronomy and astrophysics : an international weekly journal}, number = {2}, publisher = {EDP Sciences}, address = {Les Ulis}, issn = {0004-6361}, doi = {10.1051/0004-6361/201015146}, pages = {10}, year = {2011}, abstract = {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.}, language = {en} }