Craniofacial developmental biology in the single-cell era.
Publication Year:
2023
PubMed ID:
37812056
Funding Grants:
Public Summary:
The way vertebrates' heads and faces have evolved has allowed for new ways of breathing, eating, communicating, and sensing their environment. The development of the head and face involves interactions between different layers of cells, including the endoderm, ectoderm, mesoderm, and a special layer called the cranial neural crest. This complex process has been the subject of study for over a century, uncovering various cell types, signaling pathways, and genes that control craniofacial development. Understanding these processes is critical for addressing human diseases and understanding vertebrate evolution. However, for many diseases and birth defects related to the head and face, we don't yet fully understand the genetic changes responsible, especially how changes in the non-coding part of the genome impact the expression of craniofacial genes. Recently, advances in genomics and single-cell technologies have offered new opportunities to gain a more comprehensive understanding of the genes and regulatory elements that shape craniofacial development in various vertebrates. These single-cell studies lead to fresh ideas that can be tested in real-life experiments.
In this review, the authors discuss the latest progress in single-cell studies of diverse craniofacial structures. They also mention the importance of validating these findings through in vivo experiments. These studies shed light on the sources and regulation of head structures during development, offering insights into the causes of structural birth defects in the vertebrate head.
Scientific Abstract:
The evolution of a unique craniofacial complex in vertebrates made possible new ways of breathing, eating, communicating and sensing the environment. The head and face develop through interactions of all three germ layers, the endoderm, ectoderm and mesoderm, as well as the so-called fourth germ layer, the cranial neural crest. Over a century of experimental embryology and genetics have revealed an incredible diversity of cell types derived from each germ layer, signaling pathways and genes that coordinate craniofacial development, and how changes to these underlie human disease and vertebrate evolution. Yet for many diseases and congenital anomalies, we have an incomplete picture of the causative genomic changes, in particular how alterations to the non-coding genome might affect craniofacial gene expression. Emerging genomics and single-cell technologies provide an opportunity to obtain a more holistic view of the genes and gene regulatory elements orchestrating craniofacial development across vertebrates. These single-cell studies generate novel hypotheses that can be experimentally validated in vivo. In this Review, we highlight recent advances in single-cell studies of diverse craniofacial structures, as well as potential pitfalls and the need for extensive in vivo validation. We discuss how these studies inform the developmental sources and regulation of head structures, bringing new insights into the etiology of structural birth anomalies that affect the vertebrate head.