title: The unicellular ancestry of animal development.
abstract: The transition to multicellularity that launched the evolution of animals from protozoa marks one of the most pivotal, and poorly understood, events in life's history. Advances in phylogenetics and comparative genomics, and particularly the study of choanoflagellates, are yielding new insights into the biology of the unicellular progenitors of animals. Signaling and adhesion gene families critical for animal development (including receptor tyrosine kinases and cadherins) evolved in protozoa before the origin of animals. Innovations in transcriptional regulation and expansions of certain gene families may have allowed the integration of cell behavior during the earliest experiments with multicellularity. The protozoan perspective on animal origins promises to provide a valuable window into the distant past and into the cellular bases of animal development.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, 142 Life Sciences Addition, #3200, 94720, USA. nking@uclink.berkeley.edu
authors.forename: Nicole
authors.initials: N
authors.lastname: King
mesh_terms: D000818:Animals; D005075:Biological Evolution; D004272:DNA, Mitochondrial / Q000378:metabolism; D004777:Environment; D056890:Eukaryota; D019143:Evolution, Molecular; D005786:Gene Expression Regulation; D016678:Genome; D008954:Models, Biological; D010802:Phylogeny; D011161:Porifera / Q000378:metabolism; D015398:Signal Transduction; D000267:Tissue Adhesions; D014158:Transcription, Genetic
chemical_list: D004272:DNA, Mitochondrial