The Origin of Metazoan Multicellularity: A Genomics and Cell Biology Perpective

Abstract

How animals or metazoans emerged from their single-celled ancestors remains a major question in biology. Recent genome data from close unicellular relatives of Metazoa has shown that the unicellular ancestor that gave rise to Metazoa was genetically much more complex than previously thought. Thus, the unicellular ancestor of animals already had a good repertoire of genes involved in cell adhesion, cell signaling, and transcriptional regulation. This suggests that co- option and an increase in gene regulation may have played an important role in the origin of animals. All this data provides insights both into the origin of animal multicellularity and the emergence of the different animal cell types.