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Kalaitzis, C. M.

Publications and source records attributed to Kalaitzis, C. M..

2 recordsLinked to original sources

Temporally distinct CDX programmes preconfigure vagal and trunk neural crest

Neural crest cells (NCCs) are progenitor cells vital in establishing the head, heart, gut and peripheral nervous system of vertebrate embryos. Disruptions to NCC development underlie neurocristopathies, which constitute a wide array of congenital anomalies. Yet how NCCs acquire defined regional identities that enable them to generate distinct derivatives along the body axis remains unclear. Here, we identify an epiblast progenitor population in mouse embryos that transiently contributes to vagal neural crest cells and trunk-to-tail derivatives. Using single-cell spatial transcriptomics across successive stages of neural crest migration, we generate a cervicothoracic cell atlas that resolves vagal and trunk neural crest cells in situ. Combining in vivo lineage tracing with in vitro models of neural crest induction, we show that despite transiently sharing a lineage, vagal and trunk neural crest arise through separate mechanisms. Temporally discrete regionalisation events mediated by CDX transcription factors establish HOX states that define vagal versus trunk identity. These findings revise models of NCC formation by demonstrating that temporally separate epiblast regionalisation events preconfigure neural crest and neural progenitor identities. More broadly, the results suggest that primary regionalisation events coordinately govern multiple cell lineages at the cervicothoracic transition, with implications for understanding neurocristopathies involving combined enteric and trunk derivatives.

developmental biology↗

Developmental cell fate choice employs two distinct cis regulatory strategies

In many developing tissues the patterns of gene expression that assign cell fate are organised by secreted signals functioning in a graded manner over multiple cell diameters. Cis Regulatory Elements (CREs) interpret these graded inputs to control gene expression. How this is accomplished remains poorly understood. In the neural tube, a gradient of the morphogen Sonic hedgehog allocates neural progenitor identity. Here, we uncover two distinct ways in which CREs translate graded Shh signaling into differential gene expression. In the majority of ventral neural progenitors a common set of CREs are used to control gene activity. These CREs integrate cell type specific inputs to control gene expression. By contrast, the most ventral progenitors use a unique set of CREs. These are established by the pioneer factor FOXA2, paralleling the role of FOXA2 in endoderm. Moreover, FOXA2 binds a subset of the same sites in neural and endoderm cells. Together the data identify distinct cis regulatory strategies for the interpretation of morphogen signaling and raise the possibility of an evolutionarily conserved role for FOXA2-mediated regulatory strategy across tissues.

developmental biology↗