Single-cell RNA analysis identifies pre-migratory neural crest cells expressing markers of differentiated derivatives

The neural crest is a migratory population of stem-like cells that contribute to multiple traits including the bones of the skull, peripheral nervous system, and pigment. How neural crest cells differentiate into diverse cell types is a fundamental question in the study of vertebrate biology. Here, we use single-cell RNA sequencing to characterize transcriptional changes associated with neural crest cell development in the zebrafish trunk during the early stages of migration. We show that neural crest cells are transcriptionally diverse and identify pre-migratory populations already expressing genes associated with differentiated derivatives, specifically in the xanthophore lineage. Further, we identify a population of Rohon–Beard neurons in the data. The data presented identify novel genetic markers for multiple trunk neural crest cell populations and Rohon–Beard neurons providing insight into previously uncharacterized genes critical for vertebrate development.

Notch controls the cell cycle to define leader versus follower identities during collective cell migration.

Coordination of cell proliferation and migration is fundamental for life, and its dysregulation has catastrophic consequences, as cancer. How cell cycle progression affects migration, and vice-versa, remains largely unknown. We address these questions by combining in silico modelling and in vivo experimentation in the zebrafish Trunk Neural Crest (TNC). TNC migrate collectively, forming chains with a leader cell directing the movement of trailing followers. We show that the acquisition of migratory identity is autonomously controlled by Notch signalling in TNC. High Notch activity defines leaders, while low Notch determines followers. Moreover, cell cycle progression is required for TNC migration and is regulated by Notch. Cells with low Notch activity stay longer in G1 and become followers, while leaders with high Notch activity quickly undergo G1/S transition and remain in S-phase longer. We propose that migratory behaviours are defined through the interaction of Notch signalling and cell cycle progression.

Early Development of The Trunk Neural Crest Cells in the Egyptian Cobra Naja H. Haje

Background: Trunk neural crest cells (TNCC) are representing a model for epithelial to mesenchymal transition, this correlates the importance of studying the migration of these cells to cancer metastasis. Reptiles are unique group of animals being very morphologically diverse and their close position to synapsid leading to mammals. Recently, more publications focused on the migratory behavior of trunk NCC during embryonic development of squamates. Only one colubrid snake has been studied so far regarding the NCC migration. Results: Here we follow the migratory behavior of TNCC with HNK1 in the elapid snake Naja h. haje from early stage to 14 days postoviposition. Comparing the colubrid snake with the Egyptian cobra showed that both snakes overall follow the same TNCC migratory pathways of both birds and mammals by following the rostral and avoiding the caudal portions of the somites. Conclusions: First, TNCC intra-somitic migration as observed in turtles supports a contributing role for TNCC to scale precursors. Second, our observation of significant numbers of migrating TNCC in the intersomitic pathway suggest interesting evolutionary differences. Together, our present results of the Egyptian cobra in combination with those on a colubrid and turtle supports intersomitic TNCC as a unique reptile phenomena.

Neuromesodermal progenitor origin of trunk neural crest in vivo

Neural crest (NC) is a vertebrate-specific population of multipotent embryonic cells predisposed to particular derivatives along the anteroposterior (A-P) axis. While only cranial NC progenitors give rise to ectomesenchymal cell types, trunk NC is biased for neuronal cell fates. By integrating multimodal single-cell analysis we uncovered heterogenous NC cells across the entire A-P axis expressing NC regulator foxd3. We pinpointed to its specific cranial and trunk auto-regulated enhancers. The trunk foxd3 enhancer, however, did not mark the bona fide NC, but bipotent tailbud neuromesodermal progenitors (NMps). A subset of these NMp-derived pro-neural cells appeared to give rise to neuronal trunk NC in amniotes in vivo, suggesting that at least a portion of trunk NC progenitors with a bias for neuronal fates originated from NMps in vivo.

Single cell RNA analysis of trunk neural crest cells in zebrafish identifies pre-migratory populations expressing markers of differentiated derivatives

The neural crest is a migratory population of stem-like cells that contribute to multiple traits including the bones of the skull, peripheral nervous system, and pigment. How neural crest cells differentiate into diverse cell types is a fundamental question in the study of vertebrate biology. Here, we use single cell RNA sequencing to characterize transcriptional changes associated with neural crest cell development in the zebrafish trunk during the early stages of migration. We show that neural crest cells are transcriptionally diverse, and identify pre-migratory populations already expressing genes associated with differentiated derivatives. Further, we identify a population of Rohon-Beard neurons that are shown to be sources of Fgf signaling in the zebrafish trunk. The data presented identify novel genetic markers for multiple trunk neural crest cell populations and Rohon-Beard neurons providing insight into previously uncharacterized genes critical for vertebrate development.