Publications in 2005

Rojas-Munoz, A., Dahm, R., and Nüsslein-Volhard, C. (2005). chokh/rx3 specifies the retinal pigment epithelium fate independently of eye morphogenesis. Dev Biol, 288(2): 348-362. PubMed

Etard, C., Behra, M., Ertzer, R., Fischer, N., Jesuthasan, S., Blader, P., Geisler, R. and Strähle, U. (2005). Mutation in the delta- subunit of the nAChR suppresses the muscle defects caused by lack of Dystrophin. Dev Dyn 234, 1016-25. PubMed

Jülich, D., Geisler, R., Holley, S.A. and the Tübingen 2000 Screen Consortium (2005). Integrinalpha5 and delta/notch signaling have complementary spatiotemporal requirements during zebrafish somitogenesis. Dev Cell. 8, 575-86. PubMed

Koudijs, M.J., den Broeder, M.J., Keijser, A., Wienholds, E., Houwing, S., van Rooijen, E.M., Geisler, R. and van Eeden, F.J. (2005) The zebrafish mutants dre, uki, and lep encode negative regulators of the hedgehog signaling pathway. PLoS Genet 1, e19. PubMed

Schönthaler, H.B., Lampert, J.M., von Lintig, J., Schwarz, H., Geisler, R. and Neuhauss, S.C. (2005). A mutation in the silver gene leads to defects in melanosome biogenesis and alterations in the visual system in the zebrafish mutant fading vision. Dev Biol 284, 421-36. PubMed

Dahm, R., Geisler, R., and Nüsslein-Volhard, C. (2005). Zebrafish (Danio rerio) genome and genetics. In Encyclopedia of Molecular Cell Biology and Molecular Medicine, R. A. Meyers, ed. (Weinheim, Wiley-VCH), vol. 15, pp. 593-626.

Cui, W.W., Low, S.E., Hirata, H., Saint-Amant, L., Geisler, R., Hume, R.I. and Kuwada, J.Y. (2005). The zebrafish shocked gene encodes a glycine transporter and is essential for the function of early neural circuits in the CNS. J Neurosci 25, 6610-20. PubMed

Sonawane, M., Carpio, Y., Geisler, R., Schwarz, H., Maischein, H.-M. and Nüsslein-Volhard, C. (2005). Zebrafish penner/lethal giant larvae 2 functions in hemidesmosome formation, maintenance of cellular morphology and growth regulation in the developing basal epidermis. Development 132, 3255-65. PubMed

Stadler, J.A., Shkumatava, A., Norton, W.H., Rau, M.J., Geisler, R., Fischer, S. and Neumann, C.J. (2005) Histone deacetylase 1 is required for cell cycle exit and differentiation in the zebrafish retina. Dev Dyn 233, 883-9. PubMed

Meijer, A.H., Verbeek, F.J., Salas-Vidal, E., Corredor-Adamez, M., Bussman, J., van der Sar, A.M., Otto, G.W., Geisler, R. and Spaink, H.P. (2005). Transcriptome profiling of adult zebrafish at the late stage of chronic tuberculosis due to Mycobacterium marinum infection. Mol Immunol 42, 1185-203 PubMed

Norton, W.H., Mangoli, M., Lele, Z., Pogoda, H.M., Diamond, B., Mercurio, S., Russell, C., Teraoka, H., Stickney, H.L., Rauch, G.-J., Heisenberg, C.-P., Houart, C., Schilling, T.F., Frohnhoefer, H.G., Rastegar, S., Neumann, C.J., Gardiner, R.M., Strähle, U., Geisler, R., Rees, M., Talbot, W.S., and Wilson, S.W. (2005). Monorail/Foxa2 regulates floorplate differentiation and specification of oligodendrocytes, serotonergic raphe neurones and cranial motoneurones. Development 132, 645-58. PubMed

Sarropoulou, E., Power, D.M., Magoulas, A., Geisler, R. and Kotoulas, G. (2005). Comparative analysis and characterization of expressed sequence tags in gilthead sea bream (Sparus aurata) liver and embryos. Aquaculture 243, 69–81. PubMed

Moussian, B., Schwarz, H., Bartoszewski, S. and Nüsslein-Volhard, C. (2005): Involvement of Chitin in Exoskeleton Morphogenesis in Drosophila melanogaster. J. of Morphology 264, 117-130.

Moussian, B., Söding, J., Schwarz, H. and Nüsslein-Volhard, C. (2005): Retroactive, a Membrane-Anchored Extracellular Protein Related to Vertebrate Snake Neurotoxin-Like Proteins, Is Required for Cuticle Organization in the Larva of Drosophila melanogaster. Dev. Dyn. 233, 1056-1063.

Moussian, B. and Roth, S. (2005). Dorsoventral Axis Formation in the Review Drosophila Embryo — Shaping and Transducing a Morphogen Gradient. Current Biol. 15, R887-R899.

Jülich, D., Hwee Lim, C., Round, J., Nicolaije, C., Schroeder, J., Davies, A., Geisler, R., Lewis, J., Jiang, Y.J., Holley, S.A. and the Tübingen 2000 Screen Consortium (2005). beamter/deltaC and the role of Notch ligands in the zebrafish somite segmentation, hindbrain neurogenesis and hypochord differentiation. Dev Biol 286, 391-404.

The Tubingen large-scale zebrafish genetic screen completed in 1996 identified a set of five genes required for orderly somite segmentation. Four of them have been molecularly identified and three were found to code for components of the Notch pathway, which are required for the coordinated oscillation of gene expression, known as the segmentation clock, in the presomitic mesoderm (PSM). Here, we show that the final member of the group, beamter (bea), codes for the Notch ligand DeltaC, and we present and characterize two new alleles, including one allele encoding for a protein truncated in the 7th EGF repeat and an allele deleting only the DSL domain which was previously shown to be necessary for ligand function. Interestingly however, when we over-express any of the mutant deltaC mRNAs, we observe antimorphic effects on both hindbrain neurogenesis and hypochord formation. Expression of bea/deltaC oscillates in the PSM, and a triple fluorescent in situ analysis of its oscillation in relation to that of other oscillating genes in the PSM reveals differences in subcellular localization of the oscillating mRNAs in individual cells in different oscillation phases. Mutations in aei/deltaD and bea/deltaC differ in the way they disrupt the oscillating expression of her1 and deltaC. Furthermore, we find that the double mutants have significantly stronger defects in hypochord formation but not in somitogenesis or hindbrain neurogenesis, indicating genetically that the two delta's may function either semi-redundantly or distinctly, depending upon context.

Sarropoulou, E., Kotoulas, G., Power, D.M. and Geisler, R. (2005). Gene expression profiling of gilthead sea bream during early development and detection of stress-related genes by the application of cDNA microarray technology. Physiol Genomics 23, 182-91.

Large-scale gene expression studies were performed for one of the main European aquaculture species, the gilthead sea bream Sparus auratus L. For this purpose, a cDNA microarray containing 10,176 clones from a cDNA library of mixed embryonic and larval stages was constructed. In addition to its importance for aquaculture, the taxonomic position and the relatively small genome size of sea bream makes it a prospective model for evolutionary biology and comparative genomics. However, so far, no large-scale analysis of gene expression exists for this species. In the present study, gene expression was analyzed in gilthead sea bream during early development, a significant period in the determination of quantitative traits and therefore of considerable interest for aquaculture. Synexpression groups expressed primarily early and late in development were determined and were composed of both known and novel genes. Furthermore, it was possible to identify stress response genes induced by cortisol injections using the cDNA microarray generated. The creation of gene expression profiles for sea bream by microarray hybridization will accelerate identification of candidate genes involved in multifactorial traits and certain regulatory pathways and will also contribute to a better understanding of the genetic background of fish physiology, which may help to improve aquaculture practices.