Cell Migration, Cell Fate and Pattern Formation During Head Development in Lungfishes and Amphibians

Abstract

Research trying to connect developmental and evolutionary biology has experienced a renaissance in the last 20 years. Developmental biology is relevant to evolution because changes in developmental processes and, ultimately, in the mechanisms that regulate development underlie the morphological changes in adult organisms that are such a prominent feature of evolution. The increasing interest in comparative approaches to animal development is largely due to the accelerating use of molecular genetics in elucidating the mechanisms of development, new methods for mapping out the fate of cells, and the incorporation of the methods for reconstructing phylogenies which have been developed by systematists. In this chapter, I will give an overview of recent and current work on the development and evolution of the head in vertebrates, using our own work on lungfishes and amphibians as an example. After a general introduction to the research field, I describe the migration, pattern formation and fate of neural crest cells as well as some general issues in evolutionary developmental morphology. Cranial neural crest development in vertebrates is evolutionarily very conserved and is beginning to be relatively well characterised biologically. It has, however received little interest from modellers. I present preliminary ideas about how the behaviour of these cells could be modelled, drawing inspiration from some recent work on Dietyostelium development as well as from own previous work on pigment cells, which are also neural crest-derived, and their pattern formation during salamander embryogenesis.