New genes in the evolution of the neural crest differentiation program

Area of Science:

• Evolutionary developmental biology
• Comparative genomics

Background:

• Neural crest cells are vital for vertebrate head development.
• Their evolutionary origin is debated, with recent findings challenging the notion of them being a vertebrate-specific innovation.
• The genetic basis of neural crest formation in early chordates is under investigation.

Purpose of the Study:

• To investigate the evolutionary origin of genes controlling neural crest development.
• To determine the proportion of neural crest genes that are vertebrate innovations.
• To understand the role of newly emerged genes in neural crest lineage diversification.

Main Methods:

• Analysis of Phenotype Ontology annotations to identify neural crest development genes.
• Phylogenetic classification of genes using a sequential blast pipeline.
• Comparative analysis of gene emergence across different tissues.

Main Results:

• Approximately 9% of neural crest genes are unique to vertebrates.
• The neural crest shows a high rate of gene emergence during vertebrate evolution compared to other tissues.
• A significant portion of novel neural crest genes encode soluble ligands involved in precursor cell specification.

Conclusions:

• Neural crest evolution is characterized by the recruitment of ancestral genes and the emergence of new signaling peptides.
• These novel signaling peptides are crucial for the complex diversification of neural crest cell lineages.
• The plasticity of the neural crest is supported by both ancient regulatory networks and newly evolved genetic components.