Zebrafish Posterior Lateral Line primordium migration requires interactions between a superficial sheath of motile cells and the skin

• Published in: eLife Vol. 9
• Main Authors: Dalle Nogare, Damian E, Natesh, Naveen, Vishwasrao, Harshad D, Shroff, Hari, Chitnis, Ajay B
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 25.11.2020; eLife Sciences Publications, Ltd; eLife Sciences Publications Ltd
• Subjects: Animals; Cell Biology; Cell Movement; collective cell migration; Developmental Biology; Embryo, Nonmammalian - physiology; Embryonic Development; Fgf; Gene Expression Regulation, Developmental - physiology; lamellipodia; lateral line primordium; Lateral Line System - embryology; Skin; Zebrafish; Zebrafish - embryology; Zebrafish Proteins - genetics; Zebrafish Proteins - metabolism; lateral line primordium; cell biology; Fgf; developmental biology; lamellipodia; Zebrafish; collective cell migration
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.58251

The Zebrafish Posterior Lateral Line primordium migrates in a channel between the skin and somites. Its migration depends on the coordinated movement of its mesenchymal-like leading cells and trailing cells, which form epithelial rosettes, or protoneuromasts. We describe a superficial population of flat primordium cells that wrap around deeper epithelialized cells and extend polarized lamellipodia to migrate apposed to the overlying skin. Polarization of lamellipodia extended by both superficial and deeper protoneuromast-forming cells depends on Fgf signaling. Removal of the overlying skin has similar effects on superficial and deep cells: lamellipodia are lost, blebs appear instead, and collective migration fails. When skinned embryos are embedded in Matrigel, basal and superficial lamellipodia are recovered; however, only the directionality of basal protrusions is recovered, and migration is not rescued. These observations support a key role played by superficial primordium cells and the skin in directed migration of the Posterior Lateral Line primordium.