Neuronal identities derived by misexpression of the POU IV sensory determinant in a protovertebrate.

The protovertebrate type A (sometimes called ) contains a series of sensory cell types distributed across the head-tail axis of swimming tadpoles. They arise from lateral regions of the neural plate that exhibit properties of vertebrate placodes and neural crest. The sensory determinant is known to work in concert with regional determinants, such as and , to produce palp sensory cells (PSCs) and bipolar tail neurons (BTNs), in head and tail regions, respectively.

Regulatory cocktail for dopaminergic neurons in a protovertebrate identified by whole-embryo single-cell transcriptomics.

The CNS of the protovertebrate contains a single cluster of dopaminergic (DA) neurons, the coronet cells, which have been likened to the hypothalamus of vertebrates. Whole-embryo single-cell RNA sequencing (RNA-seq) assays identified as the most strongly expressed cell-specific transcription factor (TF) in DA/coronet cells. Knockdown of activity results in their loss, while misexpression results in the appearance of supernumerary DA/coronet cells.

Shared evolutionary origin of vertebrate neural crest and cranial placodes.

Placodes and neural crests represent defining features of vertebrates, yet their relationship remains unclear despite extensive investigation. Here we use a combination of lineage tracing, gene disruption and single-cell RNA-sequencing assays to explore the properties of the lateral plate ectoderm of the proto-vertebrate, Ciona intestinalis. There are notable parallels between the patterning of the lateral plate in Ciona and the compartmentalization of the neural plate ectoderm in vertebrates.

Conserved gene regulatory module specifies lateral neural borders across bilaterians.

The lateral neural plate border (NPB), the neural part of the vertebrate neural border, is composed of central nervous system (CNS) progenitors and peripheral nervous system (PNS) progenitors. In invertebrates, PNS progenitors are also juxtaposed to the lateral boundary of the CNS. Whether there are conserved molecular mechanisms determining vertebrate and invertebrate lateral neural borders remains unclear.