Nicole King
Encyclopedia
Nicole King is an American biologist and faculty member at the University of California, Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...

 in molecular and cell biology and integrative biology. She was awarded a MacArthur Fellowship in 2005.

King studies the evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...

 of multicellularity, and her work on choanoflagellates has significantly advanced our understanding of how multicellular animals evolved from single-celled organisms.

Professional contributions

King has been a pioneer in identifying 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
Comparative genomics
Comparative genomics is the study of the relationship of genome structure and function across different biological species or strains. Comparative genomics is an attempt to take advantage of the information provided by the signatures of selection to understand the function and evolutionary...

 work in collaboration with Sean Carroll
Sean B. Carroll
Sean B. Carroll is a Professor of Molecular Biology, Genetics, and Medical Genetics at the University of Wisconsin–Madison. He studies the evolution of cis-regulation in the context of biological development, using Drosophila as a model system...

 has also significantly advanced the understanding of the evolutionary "tree of life
Tree of Life
The tree of life in the Book of Genesis is a tree planted by God in midst of the Garden of Eden , whose fruit gives everlasting life, i.e. immortality. Together with the tree of life, God planted the tree of the knowledge of good and evil . According to some scholars, however, these are in fact...

," and charts the evolutionary relationship of all organisms to each other. Additionally, work by King and colleagues shows that choanoflagellates possess several protein-coding genes that are highly related to protein-coding genes
Gênes
Gênes is the name of a département of the First French Empire in present Italy, named after the city of Genoa. It was formed in 1805, when Napoleon Bonaparte occupied the Republic of Genoa. Its capital was Genoa, and it was divided in the arrondissements of Genoa, Bobbio, Novi Ligure, Tortona and...

 in animals at the base of the metazoan tree, such as sponges, cnidarians, and ctenophore
Ctenophore
The Ctenophora are a phylum of animals that live in marine waters worldwide. Their most distinctive feature is the "combs", groups of cilia that they use for swimming, and they are the largest animals that swim by means of cilia – adults of various species range from a few millimeters to in size...

s.

More recent work by King demonstrates that molecules thought to underpin the transition to multicellarity actually existed in the single-celled choanoflagellates, long before the evolution of multicellular animals. For example, one of the most abundant and important cell adhesion
Cell adhesion
Cellular adhesion is the binding of a cell to a surface, extracellular matrix or another cell using cell adhesion molecules such as selectins, integrins, and cadherins. Correct cellular adhesion is essential in maintaining multicellular structure...

 molecules in the animal kingdom, cadherin
Cadherin
Cadherins are a class of type-1 transmembrane proteins. They play important roles in cell adhesion, ensuring that cells within tissues are bound together. They are dependent on calcium ions to function, hence their name.The cadherin superfamily includes cadherins, protocadherins, desmogleins, and...

, 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 the choanoflagellates possess genes
Gênes
Gênes is the name of a département of the First French Empire in present Italy, named after the city of Genoa. It was formed in 1805, when Napoleon Bonaparte occupied the Republic of Genoa. Its capital was Genoa, and it was divided in the arrondissements of Genoa, Bobbio, Novi Ligure, Tortona and...

 that animal cells use to "talk" or signal to one another, such as Receptor tyrosine kinase
Receptor tyrosine kinase
Receptor tyrosine kinases s are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase proteins....

. These findings represent a paradigm shift in the understanding about what events led to the origin of animals.

King continues her studies on choanoflagellates and multicellularity as an assistant professor at the University of California, Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...

. King received her B.S. from Indiana University
Indiana University
Indiana University is a multi-campus public university system in the state of Indiana, United States. Indiana University has a combined student body of more than 100,000 students, including approximately 42,000 students enrolled at the Indiana University Bloomington campus and approximately 37,000...

 in 1992, in the lab of Thom Kaufman, working on the genetic workhorse, the fruitfly, also known as Drosophila melanogaster
Drosophila melanogaster
Drosophila melanogaster is a species of Diptera, or the order of flies, in the family Drosophilidae. The species is known generally as the common fruit fly or vinegar fly. Starting from Charles W...

. 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
University of Wisconsin–Madison
The University of Wisconsin–Madison is a public research university located in Madison, Wisconsin, United States. Founded in 1848, UW–Madison is the flagship campus of the University of Wisconsin System. It became a land-grant institution in 1866...

 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.

King has been recognized as a leading thinker in evolutionary biology, both by the MacArthur Foundation's "genius" award (2005) and the Pew Scholars Program in the Biomedical Sciences (2004).

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK