The interplay between Wnt signaling pathways and microtubule dynamics.

Wnt signaling pathways represent an evolutionarily highly conserved, intricate network of molecular interactions that regulates various aspects of cellular behavior, including embryonic development and tissue homeostasis. Wnt signaling pathways share the β-catenin-dependent (canonical) and the multiple β-catenin-independent (non-canonical) pathways. These pathways collectively orchestrate a wide range of cellular processes through distinct mechanisms of action.

Coordination of Cilia Movements in Multi-Ciliated Cells.

Multiple motile cilia are formed at the apical surface of multi-ciliated cells in the epithelium of the oviduct or the fallopian tube, the trachea, and the ventricle of the brain. Those cilia beat unidirectionally along the tissue axis, and this provides a driving force for directed movements of ovulated oocytes, mucus, and cerebrospinal fluid in each of these organs. Furthermore, cilia movements show temporal coordination between neighboring cilia.

Intercellular and intracellular cilia orientation is coordinated by CELSR1 and CAMSAP3 in oviduct multi-ciliated cells.

The molecular mechanisms by which cilia orientation is coordinated within and between multi-ciliated cells (MCCs) are not fully understood. In the mouse oviduct, MCCs exhibit a characteristic basal body (BB) orientation and microtubule gradient along the tissue axis. The intracellular polarities were moderately maintained in cells lacking CELSR1 (cadherin EGF LAG seven-pass G-type receptor 1), a planar cell polarity (PCP) factor involved in tissue polarity regulation, although the intercellular coordination of the polarities was disrupted.

Map7/7D1 and Dvl form a feedback loop that facilitates microtubule remodeling and Wnt5a signaling.

The Wnt signaling pathway can be grouped into two classes, the β-catenin-dependent and β-catenin-independent pathways. Wnt5a signaling through a β-catenin-independent pathway promotes microtubule (MT) remodeling during cell-substrate adhesion, cell migration, and planar cell polarity formation. Although Wnt5a signaling and MT remodeling are known to form an interdependent regulatory loop, the underlying mechanism remains unknown.

Difference in Dachsous Levels between Migrating Cells Coordinates the Direction of Collective Cell Migration.

In contrast to extracellular chemotactic gradients, how cell-adhesion molecules contribute to directing cell migration remains more elusive. Here we studied the collective migration of Drosophila larval epidermal cells (LECs) along the anterior-posterior axis and propose a migrating cell group-autonomous mechanism in which an atypical cadherin Dachsous (Ds) plays a pivotal role. In each abdominal segment, the amount of Ds in each LEC varied along the axis of migration (Ds imbalance), which polarized Ds localization at cell boundaries.

A novel planar polarity gene pepsinogen-like regulates wingless expression in a posttranscriptional manner.

Background: Planar cell polarity (PCP) originally referred to the coordination of global organ axes and individual cell polarity within the plane of the epithelium. More recently, it has been accepted that pertinent PCP regulators play essential roles not only in epithelial sheets, but also in various rearranging cells.

Results: We identified pepsinogen-like (pcl) as a new planar polarity gene, using Drosophila wing epidermis as a model.