Notch and Hippo signaling converge on Strawberry Notch 1 (Sbno1) to synergistically activate Cdx2 during specification of the trophectoderm.

The first binary cell fate decision occurs at the morula stage and gives rise to two distinct types of cells that constitute the trophectoderm (TE) and inner cell mass (ICM). The cell fate determinant, Cdx2, is induced in TE cells and plays an essential role in their differentiation and maintenance. Notch and Hippo signaling cascades are assumed to converge onto regulatory elements of Cdx2, however, the underlying molecular mechanisms are largely unknown.

Haemodynamically dependent valvulogenesis of zebrafish heart is mediated by flow-dependent expression of miR-21.

Heartbeat is required for normal development of the heart, and perturbation of intracardiac flow leads to morphological defects resembling congenital heart diseases. These observations implicate intracardiac haemodynamics in cardiogenesis, but the signalling cascades connecting physical forces, gene expression and morphogenesis are largely unknown. Here we use a zebrafish model to show that the microRNA, miR-21, is crucial for regulation of heart valve formation.

Heartbeat regulates cardiogenesis by suppressing retinoic acid signaling via expression of miR-143.

Cardiogenesis proceeds with concomitant changes in hemodynamics to accommodate the circulatory demands of developing organs and tissues. In adults, circulatory adaptation is critical for the homeostatic regulation of blood circulation. In these hemodynamics-dependent processes of morphogenesis and adaptation, a mechanotransduction pathway, which converts mechanical stimuli into biological outputs, plays an essential role, although its molecular nature is largely unknown.

Csrp1 regulates dynamic cell movements of the mesendoderm and cardiac mesoderm through interactions with Dishevelled and Diversin.

Zebrafish Csrp1 is a member of the cysteine- and glycine-rich protein (CSRP) family and is expressed in the mesendoderm and its derivatives. Csrp1 interacts with Dishevelled 2 (Dvl2) and Diversin (Div), which control cell morphology and other dynamic cell behaviors via the noncanonical Wnt and JNK pathways. When csrp1 message is knocked down, abnormal convergent extension cell movement is induced, resulting in severe deformities in midline structures.

Daam1 regulates the endocytosis of EphB during the convergent extension of the zebrafish notochord.

Convergent extension (CE) movement of cells is one of the fundamental processes that control the organized morphogenesis of tissues and organs. The molecular events connecting the noncanonical Wnt pathway and CE movement, however, are not well understood. We show that subcellular localization of Daam1, an essential component of noncanonical Wnt signaling, changes dynamically during notochord formation.