Sog/Chordin is required for ventral-to-dorsal Dpp/BMP transport and head formation in a short germ insect.
Bone morphogenetic protein (BMP) signaling plays a major role in dorsoventral patterning in vertebrates and in Drosophila. Remarkably, in Tribolium, a beetle with an ancestral type of insect development, early BMP/dpp exhibits differential expression along the anteroposterior axis. However, the BMP/Dpp inhibitor Sog/chordin is expressed ventrally and establishes a dorsal domain of BMP/Dpp activity by transporting BMPs toward the dorsal side, like in Drosophila. Loss of Tribolium Sog not only abolishes dorsoventral polarity in the ectoderm, but also leads to the complete absence of the CNS. This phenotype suggests that sog is the main BMP antagonist in Tribolium, in contrast to vertebrates and Drosophila, which possess redundant antagonists. Surprisingly, Sog also is required for head formation in Tribolium, as are the BMP antagonists in vertebrates. Thus, in Tribolium, the system of BMP and its antagonists is less complex than in Drosophila or vertebrates and combines features from both, suggesting that it might represent an ancestral state.
van der Zee
Maurijn
M
Institut für Entwicklungsbiologie, Universität zu Köln, Gyrhofstrasse 17, 50923 Cologne, Germany.
Stockhammer
Oliver
O
von Levetzow
Cornelia
C
Nunes da Fonseca
Rodrigo
R
Roth
Siegfried
S
D000818:Animals; D030801:Animals, Genetically Modified; D001756:Blastoderm / Q000378:metabolism; D019521:Body Patterning; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D006257:Head / Q000196:embryology*; D007301:Insect Hormones / Q000235:genetics / Q000378:metabolism*; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010641:Phenotype; D021381:Protein Transport; D034622:RNA Interference; D015398:Signal Transduction; D013131:Spine / Q000196:embryology / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014231:Tribolium / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*
D019485:Bone Morphogenetic Proteins; D006023:Glycoproteins; D007301:Insect Hormones; D019476:Insect Proteins; D036341:Intercellular Signaling Peptides and Proteins; D016212:Transforming Growth Factor beta; C054234:chordin