News from CEXS-UPF
The formation and maintenance of boundaries between neighboring groups of embryonic cells is crucial for development because groups of cells with distinct functions must often be kept physically separated. Furthermore, cells at the boundary often are able to instruct surrounding cells or tissues, so boundary shape and integrity might also control the outcome of many downstream patterning events. And importantly, tissue interface deregulation plays a key role during tumor progression and metastasis.
In this work, Calzolari, Terriente and Pujades, demonstrate that in the hindbrain of zebrafish embryos, once gene expression domains have achieved sharp rhombomeric boundaries due to cell sorting, actomyosin cytoskeletal components are enriched at interhombomeric boundaries. These actomyosin-based barriers prevent cells from invading neighboring compartments especially upon cell division; when the formation of the actomyosin cable is compromised, rhombomeric cell mixing can occur. Interestingly, the EphA/ephrin signaling pathway plays an important role in cable stabilization because downregulation of EphA4a is sufficient for the disruption of actomyosin cables and cell intermingling.
Calzolari S, Terriente J, and Pujades C. Cell segregation in the vertebrate hindbrain relies on actomyosin cables located at the interhombomeric boundaries. EMBO J, Published online 25.02.2014