BMP inhibition by DAN in Hensen's node is a critical step for the establishment of left–right asymmetry in the chick embryo

• Published in: Developmental biology 2012-03, Vol.363 (1), p.15-26
• Main Authors: Katsu, Kenjiro, Tokumori, Daisuke, Tatsumi, Norifumi, Suzuki, Atsushi, Yokouchi, Yuji
• Format: Article
• Language: English
• Subjects: adverse effects; Animals; Avian Proteins - genetics; Avian Proteins - metabolism; Benzamides - pharmacology; BMP; Body Patterning - genetics; Bone Morphogenetic Protein 4 - genetics; Bone Morphogenetic Protein 4 - metabolism; bone morphogenetic proteins; Cercopithecus aethiops; Chick; Chick Embryo - embryology; Chick Embryo - metabolism; chickens; chicks; COS Cells; DAN; Dioxoles - pharmacology; embryo (animal); Gene Expression Regulation, Developmental; gene overexpression; Hedgehog Proteins - genetics; Hedgehog Proteins - metabolism; In Situ Hybridization; in vitro studies; Intracellular Signaling Peptides and Proteins - genetics; Intracellular Signaling Peptides and Proteins - metabolism; Left-Right Determination Factors - genetics; Left-Right Determination Factors - metabolism; Left–right asymmetry; Mesoderm - embryology; Mesoderm - metabolism; Models, Genetic; Nodal Protein - genetics; Nodal Protein - metabolism; Notochord - embryology; Notochord - metabolism; Organizers, Embryonic - embryology; Organizers, Embryonic - metabolism; Protein Binding; Reverse Transcriptase Polymerase Chain Reaction; RNA; RNA Interference; Signal Transduction - drug effects; Signal Transduction - genetics; Sulpiride - analogs & derivatives; transforming growth factor beta; Xenopus
• ISSN: 0012-1606; 1095-564X
• DOI: 10.1016/j.ydbio.2011.12.015

During left–right (L–R) axis formation, Nodal is expressed in the node and has a central role in the transfer of L–R information in the vertebrate embryo. Bone morphogenetic protein (BMP) signaling also has an important role for maintenance of gene expression around the node. Several members of the Cerberus/Dan family act on L–R patterning by regulating activity of the transforming growth factor-β (TGF-β) family. We demonstrate here that chicken Dan plays a critical role in L–R axis formation. Chicken Dan is expressed in the left side of the node shortly after left-handed Shh expression and before the appearance of asymmetrically expressed genes in the lateral plate mesoderm (LPM). In vitro experiments revealed that DAN inhibited BMP signaling but not NODAL signaling. SHH had a positive regulatory effect on Dan expression while BMP4 had a negative effect. Using overexpression and RNA interference-mediated knockdown strategies, we demonstrate that Dan is indispensable for Nodal expression in the LPM and for Lefty-1 expression in the notochord. In the perinodal region, expression of Dan and Nodal was independent of each other. Nodal up-regulation by DAN required NODAL signaling, suggesting that DAN might act synergistically with NODAL. Our data indicate that Dan plays an essential role in the establishment of the L–R axis by inhibiting BMP signaling around the node. ► Dan is expressed in the left side of the node. ► DAN inhibits BMP signaling but not NODAL signaling. ► Dan is indispensable for Nodal in the LPM and for Lefty-1 in the notochord. ► Nodal up-regulation by DAN requires NODAL signaling. ► DAN might act synergistically with NODAL to induce Nodal and Lefty-1.