Genome-wide identification of Tribolium dorsoventral patterning genes.
The gene regulatory network controlling dorsoventral axis formation in insects has undergone drastic evolutionary changes. In Drosophila, a stable long-range gradient of Toll signalling specifies ventral cell fates and restricts BMP signalling to the dorsal half of the embryo. In Tribolium, however, Toll signalling is transient and only indirectly controls BMP signalling. In order to gain unbiased insights into the Tribolium network, we performed comparative transcriptome analyses of embryos with various dorsoventral pattering defects produced by parental RNAi for Toll and BMP signalling components. We also included embryos lacking the mesoderm (produced by Tc-twist RNAi) and characterized similarities and differences between Drosophila and Tribolium twist loss-of-function phenotypes. Using stringent conditions, we identified over 750 differentially expressed genes and analysed a subset with altered expression in more than one knockdown condition. We found new genes with localized expression and showed that conserved genes frequently possess earlier and stronger phenotypes than their Drosophila orthologues. For example, the leucine-rich repeat (LRR) protein Tartan, which has only a minor influence on nervous system development in Drosophila, is essential for early neurogenesis in Tribolium and the Tc-zinc-finger homeodomain protein 1 (Tc-zfh1), the orthologue of which plays a minor role in Drosophila muscle development, is essential for maintaining early Tc-twist expression, indicating an important function for mesoderm specification.
Institute of Developmental Biology, Biocenter, Zuelpicher Str. 47b, University of Cologne, Cologne 50674, Germany.
Dominik
D
Stappert
Institute of Developmental Biology, Biocenter, Zuelpicher Str. 47b, University of Cologne, Cologne 50674, Germany.
Nadine
N
Frey
Centrum für Integrierte Onkologie (CIO) Köln Bonn, Universitätsklinikum Köln, Kerpener Str. 62, Köln 50937, Germany.
Cornelia
C
von Levetzow
Institute of Developmental Biology, Biocenter, Zuelpicher Str. 47b, University of Cologne, Cologne 50674, Germany siegfried.roth@uni-koeln.de.
Siegfried
0000-0001-5772-3558
S
Roth
D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D047108:Embryonic Development / Q000235:genetics; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D017344:Genes, Insect; D016678:Genome; D008648:Mesoderm / Q000196:embryology / Q000378:metabolism; D054258:Neural Plate / Q000378:metabolism; D010641:Phenotype; D014231:Tribolium / Q000196:embryology* / Q000235:genetics*
BMP signalling; FGF signalling; Gastrulation; Toll/NF-κB signalling; Transcriptome analysis; twist