Developmental homology in deep time - revealed by the complex adaptive system of vertebrate odontode skeleton

It is surprisingly common to find phenotypic characters being lost independently and then regained many times.

When the developmental process underlying such characters are examined, it becomes clear that apparently homologous features can be produced by different developmental pathways, whereas structures that occur patchily may have a conserved developmental basis.

In order to investigate how novelties can emerge via modifying the pre-existing developmental programs or borrowing the toolkits from other cell lineages, the odontode skeleton will be used as the model system.

Odontodes, including teeth and tooth-like units covering the body, occur almost throughout the vertebrate evolutionary history. The rich fossil record of odontodes provides a unique window to explore the role of development in deep-time evolution.

I will use 3D synchrotron microtomography to reverse-engineer the dental ontogeny in both fossil and living animals at single-cell resolution.

In collaboration with Jan Stundl (CalTech), I will locate the gene expression signals to individual cells that are visualized in 3D through the dental development in living animals, to study the potential molecular basis.

With Miguel Brun-Usan (U. of Southampton) I will perform computer simulations to test the acquisition of new dental patterns by manipulating certain parameters.

The project will provide unprecedented insights into the odontode patterning mechanisms, which may be appliable in other morphogenetic systems.