Nicole King (born 1970) is an American biologist and faculty member at the University of California, Berkeley in molecular and cell biology and integrative biology. She was awarded a MacArthur Fellowship in 2005.
King identified choanoflagellates as key organisms to answer questions about the origin of multicellularity. Prior to her work, it was unclear whether choanoflagellates or fungi were the closest outgroup to multicellular animals (also called "metazoans"). King's comparative genomics work in collaboration with Sean Carroll helped to elucidate the evolutionary "tree of life." In addition, work by King and colleagues showed that choanoflagellates possess several protein-coding genes that are highly related to protein-coding genes in animals at the base of the metazoan tree, such as sponges, cnidarians, and ctenophores.
More recent work by King demonstrates that molecules thought to underpin the transition to multicellarity also exist in choanoflagellates and therefore were present in the single-celled and colonial ancestors of animals. For example, one of the most abundant and important cell adhesion molecules in the animal kingdom, cadherin, exists in choanoflagellates. In animals, cadherins are required to keep cells attached to their neighbors, so it was a surprising to discover that cadherins predate the evolution of animals. In addition, King found that choanoflagellates possess genes that animal cells use to "talk" or signal to one another, such as Receptor tyrosine kinase.
King continues her studies on choanoflagellates and multicellularity as an associate professor at the University of California, Berkeley. King received her B.S. from Indiana University in 1992, in the lab of Thom Kaufman, working on the genetic workhorse, the fruitfly, also known as Drosophila melanogaster. She did her graduate work at Harvard (A.M., 1996, and Ph.D., 1999), studying spore formation in Bacillus subtilis. After completing a postdoctoral fellowship at the University of Wisconsin–Madison in 2003, she accepted the position of assistant professor of genetics and development at the University of California, Berkeley.
King's lab has developed and maintained ChoanoBase, a genetic library about choanaflagellates.
- Gill, Aman Singh. "United we stand: The origins of multicellular animals," Berkeley Science Review #10 (2005).
- King, N. "The unicellular ancestry of animal development." Developmental Cell volume 7, pp. 313–325 (2004).
- King, N., Hittinger, C.T., and Carroll, S.B. "Evolution of key cell signaling and adhesion protein families predates the origin of animals." Science v. 301 (5631), pp. 361–363 (2003).
- Whitehouse, D. "Ancient ancestor's legacy of life." BBC News 22 July 2003.