Her9 controls the stemness properties of hindbrain boundary cells.

The different spatiotemporal distribution of progenitor and neurogenic capacities permits that brain regions engage asynchronously in neurogenesis. In the hindbrain, rhombomere progenitor cells contribute to neurons during the first neurogenic phase, whereas boundary cells participate later. To analyze what maintains boundary cells as non-neurogenic progenitors, we addressed the role of Her9, a zebrafish Hes1-related protein.

Yap/Taz-TEAD activity links mechanical cues to progenitor cell behavior during zebrafish hindbrain segmentation.

Cells perceive their microenvironment through chemical and physical cues. However, how the mechanical signals are interpreted during embryonic tissue deformation to result in specific cell behaviors is largely unknown. The Yap/Taz family of transcriptional co-activators has emerged as an important regulator of tissue growth and regeneration, responding to physical cues from the extracellular matrix, and to cell shape and actomyosin cytoskeletal changes.

Evolutionary emergence of the // regulatory cluster refined mechanisms for hindbrain boundaries formation.

Developmental programs often rely on parallel morphogenetic mechanisms that guarantee precise tissue architecture. While redundancy constitutes an obvious selective advantage, little is known on how novel morphogenetic mechanisms emerge during evolution. In zebrafish, rhombomeric boundaries behave as an elastic barrier, preventing cell intermingling between adjacent compartments.

The Order and Place of Neuronal Differentiation Establish the Topography of Sensory Projections and the Entry Points within the Hindbrain.

Establishing topographical maps of the external world is an important but still poorly understood feature of the vertebrate sensory system. To study the selective innervation of hindbrain regions by sensory afferents in the zebrafish embryo, we mapped the fine-grained topographical representation of sensory projections at the central level by specific photoconversion of sensory neurons. Sensory ganglia located anteriorly project more medially than do ganglia located posteriorly, and this relates to the order of sensory ganglion differentiation.