caa a22 4500 475767721 CHVBK 20180406123611.0 cr unu---uuuuu 170329e20000501xx s 000 0 eng 10.1007/s004270050316 doi (NATIONALLICENCE)springer-10.1007/s004270050316 Patterning defects in the primary axonal scaffolds caused by the mutations of the extradenticle and homothorax genes in the embryonic Drosophila brain [Elektronische Daten] [T. Nagao, K. Endo, H. Kawauchi, U. Walldorf, K. Furukubo-Tokunaga] Abstract : During early brain development in Drosophila a highly stereotyped pattern of axonal scaffolds evolves by precise pioneering and selective fasciculation of neural fibers in the newly formed brain neuromeres. Using an axonal marker, Fasciclin II, we show that the activities of the extradenticle (exd) and homothorax (hth) genes are essential to this axonal patterning in the embryonic brain. Both genes are expressed in the developing brain neurons, including many of the tract founder cluster cells. Consistent with their expression profiles, mutations of exd and hth strongly perturb the primary axonal scaffolds. Furthermore, we show that mutations of exd and hth result in profound patterning defects of the developing brain at the molecular level including stimulation of the orthodenticle gene and suppression of the empty spiracles and cervical homeotic genes. In addition, expression of a Drosophila Pax6 gene, eyeless, is significantly suppressed in the mutants except for the most anterior region. These results reveal that, in addition to their homeotic regulatory functions in trunk development, exd and hth have important roles in patterning the developing brain through coordinately regulating various nuclear regulatory genes, and imply molecular commonalities between the developmental mechanisms of the brain and trunk segments, which were conventionally considered to be largely independent. Springer-Verlag Berlin Heidelberg, 2000 Key words Brain development nationallicence Axonal scaffold nationallicence Extradenticle nationallicence Homothorax nationallicence Drosophila nationallicence Nagao T. Institute of Biological Sciences, University of Tsukuba, Tsukuba 305-8572, Japan E-mail: tokunaga@sakura.cc.tsukuba.ac.jp, JP aut Endo K. Institute of Biological Sciences, University of Tsukuba, Tsukuba 305-8572, Japan E-mail: tokunaga@sakura.cc.tsukuba.ac.jp, JP aut Kawauchi H. Institute of Biological Sciences, University of Tsukuba, Tsukuba 305-8572, Japan E-mail: tokunaga@sakura.cc.tsukuba.ac.jp, JP aut Walldorf U. Institute of Genetics, University of Hohenheim, Garbenstrasse 30, 70599 Stuttgart, Germany, DE aut Furukubo-Tokunaga K. Institute of Biological Sciences, University of Tsukuba, Tsukuba 305-8572, Japan E-mail: tokunaga@sakura.cc.tsukuba.ac.jp, JP aut https://doi.org/10.1007/s004270050316 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s004270050316 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Nagao T. Institute of Biological Sciences, University of Tsukuba, Tsukuba 305-8572, Japan E-mail: tokunaga@sakura.cc.tsukuba.ac.jp, JP aut NATIONALLICENCE 700 1- Endo K. Institute of Biological Sciences, University of Tsukuba, Tsukuba 305-8572, Japan E-mail: tokunaga@sakura.cc.tsukuba.ac.jp, JP aut NATIONALLICENCE 700 1- Kawauchi H. Institute of Biological Sciences, University of Tsukuba, Tsukuba 305-8572, Japan E-mail: tokunaga@sakura.cc.tsukuba.ac.jp, JP aut NATIONALLICENCE 700 1- Walldorf U. Institute of Genetics, University of Hohenheim, Garbenstrasse 30, 70599 Stuttgart, Germany, DE aut NATIONALLICENCE 700 1- Furukubo-Tokunaga K. Institute of Biological Sciences, University of Tsukuba, Tsukuba 305-8572, Japan E-mail: tokunaga@sakura.cc.tsukuba.ac.jp, JP aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer