Marc Wallace Kirschner (born February 28, 1945) is an American cell biologist and biochemist and the founding chair of the Department of Systems Biology at

Harvard Medical School Harvard Medical School (HMS) is the medical school of Harvard University and is located in the Longwood Medical and Academic Area, Longwood Medical Area in Boston, Massachusetts. Founded in 1782, HMS is the third oldest medical school in the Un ...

. He is known for major discoveries in cell and developmental biology related to the dynamics and function of the

cytoskeleton The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell nucleus to the cell membrane and is compos ...

, the regulation of the

cell cycle The cell cycle, or cell-division cycle, is the sequential series of events that take place in a cell (biology), cell that causes it to divide into two daughter cells. These events include the growth of the cell, duplication of its DNA (DNA re ...

, and the process of signaling in embryos, as well as the evolution of the vertebrate body plan. He is a leader in applying mathematical approaches to biology. He is the John Franklin Enders University Professor at

Harvard University Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyma ...

. In 1989 he was elected to the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, NGO, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the ...

. In 2021 he was elected to the

American Philosophical Society The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...

Early life and education

Kirschner was born in

Chicago Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...

, Illinois, on February 28, 1945. He graduated from

Northwestern University Northwestern University (NU) is a Private university, private research university in Evanston, Illinois, United States. Established in 1851 to serve the historic Northwest Territory, it is the oldest University charter, chartered university in ...

with a B.A. in chemistry in 1966. He participated in the NSF Graduate Research Fellowship Program at the

National Science Foundation The U.S. National Science Foundation (NSF) is an Independent agencies of the United States government#Examples of independent agencies, independent agency of the Federal government of the United States, United States federal government that su ...

in 1966, and earned a doctorate in biochemistry from the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

in 1971.

Career

He held

postdoctoral A postdoctoral fellow, postdoctoral researcher, or simply postdoc, is a person professionally conducting research after the completion of their doctoral studies (typically a PhD). Postdocs most commonly, but not always, have a temporary acade ...

positions at

and at the

University of Oxford The University of Oxford is a collegiate university, collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the List of oldest un ...

in England. He became assistant professor at

Princeton University Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...

in 1972. In 1978 he was made professor at the

University of California, San Francisco The University of California, San Francisco (UCSF) is a Public university, public Land-grant university, land-grant research university in San Francisco, California, United States. It is part of the University of California system and is dedic ...

. In 1993, he moved to

, where he served as the chair of the new Department of Cell Biology for a decade. He became the founding chair of the HMS Department of Systems Biology in 2003. He was named the John Franklin Enders University Professor in 2009.Ireland
"Kirschner and King named University Professors"
''Harvard Gazette'', 23 July 2009 (retrieved 16 May 2012) In 2018, he was succeeded as Chair of the Department of Systems Biology by Galit Lahav. Kirschner studies how cells divide, how they generate their shape, how they control their size, and how embryos develop. In his eclectic lab, developmental work on the frog coexists with biochemical work on mechanism of

ubiquitination Ubiquitin is a small (8.6 kDa) regulatory protein found in most tissues of eukaryotic organisms, i.e., it is found ''ubiquitously''. It was discovered in 1975 by Gideon Goldstein and further characterized throughout the late 1970s and 19 ...

assembly or

signal transduction Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a biochemical cascade, series of molecular events. Proteins responsible for detecting stimuli are generally termed receptor (biology), rece ...

. At Princeton, his early work on

microtubules Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nm and have an inner diameter between 11 an ...

established their unusual molecular assembly from tubulin proteins and identified the first microtubule-stabilizing protein

tau Tau (; uppercase Τ, lowercase τ or \boldsymbol\tau; ) is the nineteenth letter of the Greek alphabet, representing the voiceless alveolar plosive, voiceless dental or alveolar plosive . In the system of Greek numerals, it has a value of 300 ...

, later shown to be a major component of the neurofibrillary tangles in Alzheimer's disease. In studies at UC San Francisco of the frog embryo as a model system of cell development, Kirschner identified the first inducer of embryonic differentiation, fibroblast growth factor (FGF), an early finding in the field of signal transduction. Kirschner's lab is also known for uncovering basic mechanisms of the cell cycle in

eukaryotic The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fungi, seaweeds, and many unicellular organisms ...

cells. Working in

Xenopus ''Xenopus'' () (Gk., ξενος, ''xenos'' = strange, πους, ''pous'' = foot, commonly known as the clawed frog) is a genus of highly aquatic frogs native to sub-Saharan Africa. Twenty species are currently described with ...

(frog) egg extracts, Kirschner and Andrew Murray showed that

cyclin Cyclins are proteins that control the progression of a cell through the cell cycle by activating cyclin-dependent kinases (CDK). Etymology Cyclins were originally discovered by R. Timothy Hunt in 1982 while studying the cell cycle of sea urch ...

synthesis drives the cell cycle and, later, that

ubiquitin Ubiquitin is a small (8.6 kDa) regulatory protein found in most tissues of eukaryotic organisms, i.e., it is found ''ubiquitously''. It was discovered in 1975 by Gideon Goldstein and further characterized throughout the late 1970s and 19 ...

regulates levels of cyclin by marking the cell-cycle molecule for destruction. His lab discovered and purified many of the components involved in cell cycle progression, including anaphase promoting complex (APC), the complex that ubiquitinates

cyclin B Cyclin B is a member of the cyclin family. Cyclin B is a mitotic cyclin. The amount of cyclin B (which binds to Cdk1) and the activity of the cyclin B-Cdk complex rise through the cell cycle until mitosis, where they fall abruptly due to degr ...

. A second noted finding was his discovery, with Tim Mitchison, of the dynamic instability of microtubules, In mitosis, for example, microtubules form the spindle that separates the chromosomes. The first step in spindle formation is the nucleation of microtubules by microtubule-organizing centers, which then grow in all directions. Microtubules that attach to a chromosome are stabilized and are therefore retained to form part of the spindle. Because of dynamic instability, some individual microtubules that are not stabilized are at risk of collapse (or “catastrophe” as Kirschner named it), allowing re-use of the tubulin

monomers A monomer ( ; ''wikt:mono-, mono-'', "one" + ''wikt:-mer, -mer'', "part") is a molecule that can chemical reaction, react together with other monomer molecules to form a larger polymer chain or two- or three-dimensional network in a process called ...

. This recognition of self-organization in biological systems has been highly influential, and helped shape the view of the cytoplasm as a collection of dynamic molecular machines. Kirschner is also interested in the evolutionary origins of the vertebrate body plan. Together with John Gerhart, he was instrumental in developing the acorn worm Saccoglossus kowalevskii into a model system that could be used to study the divergence between

hemichordate Hemichordata ( ) is a phylum which consists of triploblastic, eucoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms. They appear in the Lower or Middle Cambrian and incl ...

s and

chordate A chordate ( ) is a bilaterian animal belonging to the phylum Chordata ( ). All chordates possess, at some point during their larval or adult stages, five distinctive physical characteristics ( synapomorphies) that distinguish them from ot ...

s, and the evolution of the

nervous system. Kirschner is a pioneer in using mathematical approaches to learn about central biological questions. For example, a model of the

Wnt pathway In cellular biology, the Wnt signaling pathways are a group of signal transduction pathways which begin with proteins that Cell signaling, pass signals into a cell through cell surface receptors. The name Wnt, pronounced "wint", is a portmanteau cr ...

he developed in collaboration with the late Reinhart Heinrich showed that new properties and constraints emerge when the individual biochemical steps are combined into a complete pathway. A talk he gave on mathematics and the future of medicine at a retreat for Department Chairs at

in 2003 inspired the Dean, Joseph B. Martin, to found a new Department, the Department of

Systems Biology Systems biology is the computational modeling, computational and mathematical analysis and modeling of complex biological systems. It is a biology-based interdisciplinary field of study that focuses on complex interactions within biological system ...

, with Kirschner as founding chair. Since then, Kirschner's lab has attracted many students and post-docs from theoretical backgrounds who wish to make the transition into biology. His lab is now a leader in using mathematical tools to analyze signaling pathways, cell size control, and the selectivity of drugs. In two books co-authored with John Gerhart, Kirschner has described the cellular and developmental underpinnings of the evolution of organisms, and the concept of "

evolvability Evolvability is defined as the capacity of a system for adaptive evolution. Evolvability is the ability of a population of organisms to not merely generate genetic diversity, but to generate '' adaptive'' genetic diversity, and thereby evolve thr ...

". In the most recent book, Kirschner and Gerhart proposed a new theory of "facilitated variation" that aims to answer the question: How can small, random genetic changes be converted into useful changes in complex body parts?

Public service

Kirschner has been an advocate for federal biomedical research funding and served as first chair of the Joint Steering Committee for Public Policy, a coalition of scientific societies he helped create in 1993 to educate the U.S. Congress on biomedical research and lobby for public funding of it. In 2014, Kirschner (together with

Bruce Alberts Bruce Michael Alberts (born April 14, 1938, in Chicago, Illinois) is an American biochemist and the Emeritus Chancellor’s Leadership Chair in Biochemistry and Biophysics for Science and Education at the University of California, San Francisco ...

, Shirley Tilghman and

Harold Varmus Harold Eliot Varmus (born December 18, 1939) is an American Nobel Prize-winning scientist. He is currently the Lewis Thomas University Professor of Medicine at Weill Cornell Medicine and a senior associate at the New York Genome Center. He was ...

) called for a number of changes to the system of US biomedical science, with the intention of reducing "hypercompetition" This publication led to the formation of an organization, Rescuing Biomedical Research, that aims to collect community input and propose changes to the structure of academic science in the USA. Kirschner helped launch the monthly, peer-reviewed journal ''

PLoS Biology ''PLOS Biology'' is a monthly peer-reviewed scientific journal covering all aspects of biology. Publication began on October 13, 2003. It is the first journal published by the Public Library of Science. The editor-in-chief is Nonia Pariente. In ...

'' in October 2003 as a member of the editorial board and senior author of a paper in the inaugural issue. The journal was the first publishing venture from the San Francisco-based Public Library of Science (PLoS), which had begun three years previously as a grassroots organization of scientists advocating free and unrestricted access to the scientific literature

Books

* wit
John Gerhart
''Cells, Embryos, and Evolution: Toward a Cellular and Developmental Understanding of Phenotypic Variation and Evolutionary Adaptability'' (

Blackwell's Blackwell UK, also known as Blackwell's and Blackwell Group, is a British academic book retailer and library supply service owned by Waterstones. It was founded in 1879 by Benjamin Henry Blackwell, after whom the chain is named, on Broad Stree ...

, 1997) * wit
John Gerhart
''The Plausibility of Life: Resolving Darwin's Dilemma''

ale University Press 2005)

Awards, Honorary Degrees and Associations

* 1989–present - Member,

American Academy of Arts and Sciences The American Academy of Arts and Sciences (The Academy) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and other ...

* 1990-1991 - President, American Society for Cell Biology * 1991 - Richard Lounsbery Award * 1996 - Public Service Award, American Society for Cell Biology * 1999–present - Foreign Member,

Royal Society of London The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, r ...

* 1999–present - Foreign Member,

Academia Europaea The Academia Europaea is a pan-European Academy of humanities, letters, law, and sciences. The Academia was founded in 1988 as a functioning Europe-wide Academy that encompasses all fields of scholarly inquiry. It acts as co-ordinator of Europe ...

* 2000 - Honorary Degree, Doctor of Sciences, University of Chicago * 2001 -

William C. Rose Award The William C. Rose Award given by the American Society for Biochemistry and Molecular Biology recognizes outstanding contributions to biochemical and molecular biological research and a demonstrated commitment to the training of younger scientists ...

American Society for Biochemistry and Molecular Biology The American Society for Biochemistry and Molecular Biology (ASBMB) is a learned society that was founded on December 26, 1906, at a meeting organized by John Jacob Abel (Johns Hopkins University). The roots of the society were in the American Ph ...

* 2001 - Gairdner Foundation International Award (Canada) * 2003 - Rabbi Shai Shacknai Memorial Prize in Immunology and Cancer Research, Hebrew University-Hadassah Medical School, Jerusalem * 2003 - E.B. Wilson Medal, American Society for Cell Biology (the ASCB's highest honor) * 2004 - Dickson Prize for Science, Carnegie Mellon University * 2015 -

Harvey Prize The Harvey Prize is an annual Israeli award for breakthroughs in science and technology, as well as contributions to peace in the Middle East granted by the Technion – Israel Institute of Technology, Technion in Haifa. The prize has become a ...

, Technion Institute, Israel. * 2023 - Honorary PhD, Rockefeller University. * 2025 - Honorary Degree, Doctor of Sciences, Northwestern University.

References

External links

Marc W. Kirschner, Ph.D., (Faculty page)
Harvard Department of Systems Biology.
Marc Kirschner
scientific publications list on Pubget. *.
Marc W. Kirschner's Seminar: "The Origin of Vertebrates"Video: "Systems questions in cell biology"
NIH Director's Wednesday Afternoon Lecture Series, 17 October 2007. (Audio podcast also available.)
Video: Lecture on evolution
in Cambridge, Mass., 30 November 2005 taped by WGBH Forum Network. (Includes explanation of "facilitated variation.")
Marc Kirschner and John Gerhart: An email interview
by Gregg Ross on ''American Scientist Online'', November 2005.
Audio: Marc Kirschner interview in "Resolving Darwin's dilemma,"
''On Point'' radio show at WBUR Boston, 18 October 2005.
Plausibility of Life discussed in "Evolving Evolution,"
by Israel Rosenfield and Edward Ziff, ''New York Review of Books,'' 11 May 2006
Rescuing Biomedical Research website
{{DEFAULTSORT:Kirschner, Marc 21st-century American biologists Jewish American scientists Foreign members of the Royal Society Living people Members of Academia Europaea Members of the United States National Academy of Sciences Northwestern University alumni American systems biologists University of California, San Francisco faculty 1945 births Extended evolutionary synthesis Harvard Medical School faculty Richard-Lounsbery Award laureates Members of the American Philosophical Society 21st-century American Jews