Rethinking Cell Differentiation and Development: A Unicellular Perspective

One of the central questions in developmental biology is how different cell fates are generated from a single founding cell. Although great strides have been made in our understanding of this problem in animals, the evolutionary origins of this process are not understood. It is known that many unicellular organisms progress through different cell stages during their life cycle, known as temporal cell differentiation, and it has been hypothesized that spatial cell differentiation (as seen in animals) evolved from this more ancient differentiation-mode. A full understanding of how this occurred has been hampered by a lack of information on the basic principles underlying temporal cell differentiation in the closest relatives of animals, the unicellular holozoans.

In recent years, several studies have revealed that many of the genes and pathways directly related to development and cell fate in animals were already present in their unicellular ancestors. Moreover, many examples have shown the formation of specialized cell types in response to specific environmental ques and transient multicellular structures have been reported in many unicellular holozoan lineages. Therefore, recent discoveries strongly point towards an earlier origin of several developmental processes, including cell differentiation, than was previously thought and make a strong case that understanding the mechanisms underpinning “development” in these unicellular lineages will be key to understand the emergence of definitive animal cell differentiation and development.

The workshop will consist of sessions of talks and discussions centred around various aspects of development to unicellular holozoans. Each session will contain a mixture of researchers working on unicellular holozoans and those working on other eukaryotic systems who will provide alternative insights. Through these sessions the workshop will build knowledge aiming to produce a white-paper document outlining the emerging conceptual framework in the field, the major outstanding questions as well as seeding collaborative efforts to address these questions.