RhoA GEF Mcf2lb regulates rosette integrity during collective cell migration.

Multicellular rosettes are transient epithelial structures that serve as important cellular intermediates in the formation of diverse organs. Using the zebrafish posterior lateral line primordium (pLLP) as a model system, we investigated the role of the RhoA GEF Mcf2lb in rosette morphogenesis. The pLLP is a group of ∼150 cells that migrates along the zebrafish trunk and is organized into epithelial rosettes; these are deposited along the trunk and will differentiate into sensory organs called neuromasts (NMs).

RhoA GEF Mcf2lb regulates rosette integrity during collective cell migration.

During development, multicellular rosettes serve as important cellular intermediates in the formation of diverse organ systems. Multicellular rosettes are transient epithelial structures that are defined by the apical constriction of cells towards the rosette center. Due to the important role these structures play during development, understanding the molecular mechanisms by which rosettes are formed and maintained is of high interest.

Lamellipodia-like protrusions and focal adhesions contribute to collective cell migration in zebrafish.

Collective cell migration is a process where cohorts of cells exhibit coordinated migratory behavior. During individual and collective cellular migration, cells must extend protrusions to interact with the extracellular environment, sense chemotactic cues, and act as points of attachment. The mechanisms and regulators of protrusive behavior have been widely studied in individually migrating cells; however, how this behavior is regulated throughout collectives is not well understood.

Nothing to Be Sniffed At: Anosmin1 Tunes Fgf Diffusivity.

The extracellular matrix plays both positive and negative roles in growth factor diffusion, a process critical for organ formation. In this issue of Developmental Cell, Wang et al. (2018) identify the extracellular matrix protein Anosmin1 as a key regulator of Fgf diffusion during sensory organ formation in zebrafish.

Using Zebrafish to Study Collective Cell Migration in Development and Disease.

Cellular migration is necessary for proper embryonic development as well as maintenance of adult health. Cells can migrate individually or in groups in a process known as collective cell migration. Collectively migrating cohorts maintain cell-cell contacts, group polarization, and exhibit coordinated behavior.