Cxcl12a induces snail1b expression to initiate collective migration and sequential Fgf-dependent neuromast formation in the zebrafish posterior lateral line primordium

Abstract

The zebrafish posterior lateral line primordium migrates along a path defined by the chemokine Cxcl12a, periodically depositing neuromasts, to pioneer formation of the zebrafish posterior lateral line system. , known for its role in promoting cell migration, is expressed in leading cells of the primordium in response to Cxcl12a, whereas its expression in trailing cells is inhibited by Fgf signaling. knockdown delays initiation of primordium migration. This delay is associated with aberrant expansion of () and reduction of expression in the leading part of the primordium. Co-injection of morpholino with mRNA prevents the initial delay in migration and restores normal expression of and The delay in initiating primordium migration in morphants is accompanied by a delay in sequential formation of trailing Fgf signaling centers and associated protoneuromasts. This delay is not specifically associated with knockdown of but also with other manipulations that delay migration of the primordium. These observations reveal an unexpected link between the initiation of collective migration and sequential formation of protoneuromasts in the primordium.

Trap-TRAP, a Versatile Tool for Tissue-Specific Translatomics in Zebrafish

“…The line TT15, which showed expression in the lateral line, contains an insertion in the chromosome 1 (Figures 3A, 3A9). This region is 5′ distal to lef1, whose expression pattern includes a lateral line domain similar to that observed in TT15 embryos (Neelathi et al, 2018). Similarly, the analysis carried out on the TT21 line, which shows expression in rhombomere number 5, indicated that the insertion occurred on chromosome 23 (Figures 3B, 3B9).…”

Trap-TRAP, a versatile tool for tissue-specific translatomics in zebrafish

“…The line TT15, which showed expression in the lateral line, contains an insertion in the chromosome 1 (Figure 3A, 3A'). This region is 5' distal to lef1, whose expression pattern includes a lateral line domain similar to that observed in TT15 embryos 29 .…”

Dynamic Buffering of Extracellular Chemokine by a Dedicated Scavenger Pathway Enables Robust Adaptation during Directed Tissue Migration

“…This fluorescent version of Cxcl12a restored tissue migration in cxcl12a-deficient embryos (Valentin et al, 2007), confirming that it is functional and expressed at physiological levels (Figures S1E and S1F). For perturbation, Cxcl12a was expressed under the control of an hsp70 promoter to turn on ubiquitous, elevated Cxcl12a expression upon temperature shift (Donà et al, 2013;Neelathi et al, 2018), which we term a chemokine flood (Figures 1B and S1C). Cxcl12a-GFP fluorescence intensity showed an increase in the chemokine flood condition compared with physiological, with intense Cxcl12a-GFP labeling of extracellularmatrix-rich interfaces, such as the horizontal myoseptum, the path of lateral line migration (Figure 1B, right).…”