A global view of gene expression in lithium and zinc treated sea urchin embryos: new components of gene regulatory networks
Date
2007-05-16
Authors
Poustka, Albert J
Kühn, Alexander
Groth, Detlef
Weise, Vesna
Yaguchi, Shunsuke
Burke, Robert D
Herwig, Ralf
Lehrach, Hans
Panopoulou, Georgia
Journal Title
Journal ISSN
Volume Title
Publisher
BioMed Central
Abstract
Background: The genome of the sea urchin Strongylocentrotus purpuratus has recently been
sequenced because it is a major model system for the study of gene regulatory networks.
Embryonic expression patterns for most genes are unknown, however.
Results: Using large-scale screens on arrays carrying 50% to 70% of all genes, we identified novel
territory-specific markers. Our strategy was based on computational selection of genes that are
differentially expressed in lithium-treated embryos, which form excess endomesoderm, and in zinctreated
embryos, in which endomesoderm specification is blocked. Whole-mount in situ
hybridization (WISH) analysis of 700 genes indicates that the apical organ region is eliminated in
lithium-treated embryos. Conversely, apical and specifically neural markers are expressed more
broadly in zinc-treated embryos, whereas endomesoderm signaling is severely reduced. Strikingly,
the number of serotonergic neurons is amplified by at least tenfold in zinc-treated embryos. WISH
analysis further indicates that there is crosstalk between the Wnt (wingless int), Notch, and
fibroblast growth factor signaling pathways in secondary mesoderm cell specification and
differentiation, similar to signaling cascades that function during development of presomitic
mesoderm in mouse embryogenesis. We provide differential expression data for more than 4,000
genes and WISH patterns of more than 250 genes, and more than 2,400 annotated WISH images.
Conclusion: Our work provides tissue-specific expression patterns for a large fraction of the sea
urchin genes that have not yet been included in existing regulatory networks and await functional
integration. Furthermore, we noted neuron-inducing activity of zinc on embryonic development;
this is the first observation of such activity in any organism.
Description
BioMed Central
Keywords
Citation
Poustka, A. et al. A global view of gene expression in lithium and zinc treated sea urchin embryos. Genome Biology 2007, 8: R85