Nuclear movement regulated by non-Smad Nodal signaling via JNK is associated with Smad signaling during zebrafish endoderm specification

• Published in: Development (Cambridge) Vol. 144; no. 21; pp. 4015 - 4025
• Main Authors: Hozumi, Shunya, Aoki, Shun, Kikuchi, Yutaka
• Format: Journal Article
• Language: English
• Published: England The Company of Biologists Ltd 01.11.2017
• Subjects: Animals; Body Patterning; Cell Movement; Cell Nucleus - metabolism; Danio rerio; Egg Yolk - metabolism; Embryo, Nonmammalian - metabolism; Endoderm; Endoderm - cytology; Endoderm - embryology; Endoderm - metabolism; Giant Cells - metabolism; JNK protein; MAP Kinase Signaling System; Microtubule-Organizing Center - metabolism; Microtubules - metabolism; Models, Biological; Nodal Protein - metabolism; Nuclear transport; Protein Transport; RNA, Messenger - genetics; RNA, Messenger - metabolism; Signal transduction; Smad protein; Smad2 protein; Smad2 Protein - metabolism; Yolk; Zebrafish - embryology; Zebrafish - metabolism; Zebrafish Proteins - metabolism; Endoderm specification; Nodal; Smad; JNK; Nuclear movement; MTOC
• ISSN: 0950-1991; 1477-9129
• DOI: 10.1242/dev.151746

Asymmetric nuclear positioning is observed during animal development, but its regulation and significance in cell differentiation remain poorly understood. Using zebrafish blastulae, we provide evidence that nuclear movement towards the yolk syncytial layer, which comprises extraembryonic tissue, occurs in the first cells fated to differentiate into the endoderm. Nodal signaling is essential for nuclear movement, whereas nuclear envelope proteins are involved in movement through microtubule formation. Positioning of the microtubule-organizing center, which is proposed to be crucial for nuclear movement, is regulated by Nodal signaling and nuclear envelope proteins. The non-Smad JNK signaling pathway, which is downstream of Nodal signaling, regulates nuclear movement independently of the Smad pathway, and this nuclear movement is associated with Smad signal transduction toward the nucleus. Our study provides insight into the function of nuclear movement in Smad signaling toward the nucleus, and could be applied to the control of TGFβ signaling.