Thu, 24 Jul 2008 23:04:33 BST CiteULike: Author Schubiger http://www.citeulike.org/author/Schubiger CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/brembs/article/2307582 <i>Current Biology, Vol. 18, No. 2. (22 January 2008), pp. R60-R62.</i><br /><br />Summary Numerical and spatial cognition rely on common functional circuits in the parietal lobes of the brain [1]. While previous work has established that the mere perception of numbers can bias a subject's attention in space [2], the method of random digit generation has only recently been introduced to a rapidly growing literature exploring asymmetries in number space [3]. Here we show that human subjects' attempts to generate numbers `at random' are systematically influenced by lateral head turns, which are known to reallocate spatial attention in the outside world. Specifically, while facing left, subjects produced relatively small numbers, whereas while facing right they tended to produce larger numbers. These results support current concepts of parietal cortex as mediating the interplay between spatial attention and abstract thought [4]. Head turns bias the brain's internal random generator Tobias Loetscher Urs Schwarz Michele Schubiger Peter Brugger doi:10.1016/j.cub.2007.11.015 Current Biology, Vol. 18, No. 2. (22 January 2008), pp. R60-R62. 2008-01-30T14:47:28-00:00 2008 Current Biology 18 2 R60 R62 numbers random spontaneous http://www.citeulike.org/user/emmahe/article/1391967 <i>Development, Vol. 132, No. 16. (15 August 2005), pp. 3753-3765.</i><br /><br />Drosophila imaginal disc cells can switch fates by transdetermining from one determined state to another. We analyzed the expression profiles of cells induced by ectopic Wingless expression to transdetermine from leg to wing by dissecting transdetermined cells and hybridizing probes generated by linear RNA amplification to DNA microarrays. Changes in expression levels implicated a number of genes: lamina ancestor, CG12534 (a gene orthologous to mouse augmenter of liver regeneration), Notch pathway members, and the Polycomb and trithorax groups of chromatin regulators. Functional tests revealed that transdetermination was significantly affected in mutants for lama and seven different PcG and trxG genes. These results validate our methods for expression profiling as a way to analyze developmental programs, and show that modifications to chromatin structure are key to changes in cell fate. Our findings are likely to be relevant to the mechanisms that lead to disease when homologs of Wingless are expressed at abnormal levels and to the manifestation of pluripotency of stem cells. 10.1242/dev.01927 Regulation of cellular plasticity in Drosophila imaginal disc cells by the Polycomb group, trithorax group and lama genes Ansgar Klebes Anne Sustar Katherina Kechris Hao Li Gerold Schubiger Thomas Kornberg doi:10.1242/dev.01927 Development, Vol. 132, No. 16. (15 August 2005), pp. 3753-3765. 2007-06-15T13:54:28-00:00 2005 Development 132 16 3753 3765 chromatin competence development imaginal_discs