Opposing nodal and BMP signals regulate left-right asymmetry in the sea urchin larva.
Nodal and BMP signals are important for establishing left-right (LR) asymmetry in vertebrates. In sea urchins, Nodal signaling prevents the formation of the rudiment on the right side. However, the opposing pathway to Nodal signaling during LR axis establishment is not clear. Here, we revealed that BMP signaling is activated in the left coelomic pouch, specifically in the veg2 lineage, but not in the small micromeres. By perturbing BMP activities, we demonstrated that BMP signaling is required for activating the expression of the left-sided genes and the formation of the left-sided structures. On the other hand, Nodal signals on the right side inhibit BMP signaling and control LR asymmetric separation and apoptosis of the small micromeres. Our findings show that BMP signaling is the positive signal for left-sided development in sea urchins, suggesting that the opposing roles of Nodal and BMP signals in establishing LR asymmetry are conserved in deuterostomes.
Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan.
Yi-Jyun
YJ
Luo
Yi-Hsien
YH
Su
D000818:Animals; D017209:Apoptosis; D019521:Body Patterning; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D007814:Larva / Q000378:metabolism; D055457:Nodal Protein / Q000378:metabolism*; D012617:Sea Urchins / Q000196:embryology / Q000254:growth & development* / Q000378:metabolism; D015398:Signal Transduction
D019485:Bone Morphogenetic Proteins; D055457:Nodal Protein