Curt Stern
Encyclopedia
Curt Stern was a German-born American geneticist
.
Curt Jacob Stern was born in Hamburg, Germany. He studied zoology
at the University of Berlin and received his PhD
in 1923 at the age of 21. He was awarded a post-graduate fellowship at Columbia University
, then the site of Thomas Hunt Morgan
's famous Fly Room (so-named for the fruit fly Drosophila
, the subject of genetic research for Morgan).
Although Stern accepted an appointment at the University of Berlin after his fellowship ended, he returned to the United States in 1932 and became an American citizen in 1939. From 1933 to 1947, he taught at the University of Rochester
. From 1947 until his retirement in 1970, he was a professor at the University of California
at Berkeley
, where he had numerous doctoral students.
In 1931, Stern was the first to demonstrate crossover
of homologous chromosomes in Drosophila melanogaster
, only weeks after Barbara McClintock
and Harriet Creighton
had done so in maize
(corn). In 1936, he demonstrated that recombination can also take place in mitosis
resulting in somatic mosaics
, organisms that contain two or more genetically distinct types of tissues. He later demonstrated that there were multiple genes on the Drosophila Y chromosome
, and described the mechanism of dosage compensation
.
During World War II
, he led research for the American government on low-dose radiation safety. His laboratory group concluded that there is no "safe" threshold below which radiation is not harmful.
, a statement by leading scientists in many fields that questioned the validity and scientific foundations of racial theories
and eugenics
.
The Curt Stern Award
, established by the American Society of Human Genetics
in 2001, recognizes a scientist who has made major scientific achievements in human genetics during the past 10 years.
Geneticist
A geneticist is a biologist who studies genetics, the science of genes, heredity, and variation of organisms. A geneticist can be employed as a researcher or lecturer. Some geneticists perform experiments and analyze data to interpret the inheritance of skills. A geneticist is also a Consultant or...
.
Curt Jacob Stern was born in Hamburg, Germany. He studied zoology
Zoology
Zoology |zoölogy]]), is the branch of biology that relates to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct...
at the University of Berlin and received his PhD
PHD
PHD may refer to:*Ph.D., a doctorate of philosophy*Ph.D. , a 1980s British group*PHD finger, a protein sequence*PHD Mountain Software, an outdoor clothing and equipment company*PhD Docbook renderer, an XML renderer...
in 1923 at the age of 21. He was awarded a post-graduate fellowship at Columbia University
Columbia University
Columbia University in the City of New York is a private, Ivy League university in Manhattan, New York City. Columbia is the oldest institution of higher learning in the state of New York, the fifth oldest in the United States, and one of the country's nine Colonial Colleges founded before the...
, then the site of Thomas Hunt Morgan
Thomas Hunt Morgan
Thomas Hunt Morgan was an American evolutionary biologist, geneticist and embryologist and science author who won the Nobel Prize in Physiology or Medicine in 1933 for discoveries relating the role the chromosome plays in heredity.Morgan received his PhD from Johns Hopkins University in zoology...
's famous Fly Room (so-named for the fruit fly Drosophila
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...
, the subject of genetic research for Morgan).
Although Stern accepted an appointment at the University of Berlin after his fellowship ended, he returned to the United States in 1932 and became an American citizen in 1939. From 1933 to 1947, he taught at the University of Rochester
University of Rochester
The University of Rochester is a private, nonsectarian, research university in Rochester, New York, United States. The university grants undergraduate and graduate degrees, including doctoral and professional degrees. The university has six schools and various interdisciplinary programs.The...
. From 1947 until his retirement in 1970, he was a professor at the University of California
University of California
The University of California is a public university system in the U.S. state of California. Under the California Master Plan for Higher Education, the University of California is a part of the state's three-tier public higher education system, which also includes the California State University...
at 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...
, where he had numerous doctoral students.
In 1931, Stern was the first to demonstrate crossover
Chromosomal crossover
Chromosomal crossover is an exchange of genetic material between homologous chromosomes. It is one of the final phases of genetic recombination, which occurs during prophase I of meiosis in a process called synapsis. Synapsis begins before the synaptonemal complex develops, and is not completed...
of homologous chromosomes in 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...
, only weeks after Barbara McClintock
Barbara McClintock
Barbara McClintock , the 1983 Nobel Laureate in Physiology or Medicine, was an American scientist and one of the world's most distinguished cytogeneticists. McClintock received her PhD in botany from Cornell University in 1927, where she was a leader in the development of maize cytogenetics...
and Harriet Creighton
Harriet Creighton
Harriet Baldwin Creighton was an American botanist, geneticist and educator.Born in Delavan, Illinois, Creighton graduated from Wellesley College in 1929, and went on to complete her Ph.D. at Cornell University in 1933...
had done so in maize
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
(corn). In 1936, he demonstrated that recombination can also take place in mitosis
Mitosis
Mitosis is the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets, in two separate nuclei. It is generally followed immediately by cytokinesis, which divides the nuclei, cytoplasm, organelles and cell membrane into two cells containing roughly...
resulting in somatic mosaics
Mosaic (genetics)
In genetic medicine, a mosaic or mosaicism denotes the presence of two populations of cells with different genotypes in one individual who has developed from a single fertilized egg...
, organisms that contain two or more genetically distinct types of tissues. He later demonstrated that there were multiple genes on the Drosophila Y chromosome
Y chromosome
The Y chromosome is one of the two sex-determining chromosomes in most mammals, including humans. In mammals, it contains the gene SRY, which triggers testis development if present. The human Y chromosome is composed of about 60 million base pairs...
, and described the mechanism of dosage compensation
Dosage compensation
Dosage compensation, also known as Ohno's Hypothesis, is a hypothetical genetic regulatory mechanism which operates to equalize the phenotypic expression of characteristics determined by genes on the X chromosome so that they are equally expressed in the human XY male and the XX female. In 2006,...
.
During World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, he led research for the American government on low-dose radiation safety. His laboratory group concluded that there is no "safe" threshold below which radiation is not harmful.
Re-founding human genetics
After the war his research focused on human genetics, pioneering in what is now known as gene regulation. Although not a physician, he engaged in clinical work in human genetics. In 1943 he began teaching a course in human genetics to medical students at the University of Rochester. The first edition of Stern's pioneering textbook The Principles of Human Genetics was published in 1949. Both his teaching and his textbook were instrumental in re-founding human genetics on a non-racist basis, in sharp contrast with pre-war German and American traditions in the subject. Stern was a signatory of the 1950 UNESCO statement The Race QuestionThe Race Question
The Race Question is the first of four UNESCO statements about issues of race. It was issued on 18 July 1950 following World War II and Nazi racism. The statement was an attempt to clarify what was scientifically known about race and a moral condemnation of racism...
, a statement by leading scientists in many fields that questioned the validity and scientific foundations of racial theories
Scientific racism
Scientific racism is the use of scientific techniques and hypotheses to sanction the belief in racial superiority or racism.This is not the same as using scientific findings and the scientific method to investigate differences among the humans and argue that there are races...
and eugenics
Eugenics
Eugenics is the "applied science or the bio-social movement which advocates the use of practices aimed at improving the genetic composition of a population", usually referring to human populations. The origins of the concept of eugenics began with certain interpretations of Mendelian inheritance,...
.
The Curt Stern Award
Curt Stern Award
The Curt Stern Award, also known as the Stern Award, honors the memory of Curt Stern as an outstanding and pioneering human geneticist...
, established by the American Society of Human Genetics
American Society of Human Genetics
The American Society of Human Genetics , founded in 1948, is the primary professional membership organization for specialists in human genetics worldwide. As of 2009, the organization had approximately 8,000 members...
in 2001, recognizes a scientist who has made major scientific achievements in human genetics during the past 10 years.
External links
- Curt Stern, biographical memoir written by James V. NeelJames V. NeelJames Van Gundia Neel was an American geneticist who played a key role in the development of human genetics as a field of research in the United States. He made important contributions to the emergence of genetic epidemiology and pursued an understanding of the influence of environment on genes...
for the National Academy of SciencesUnited States National Academy of SciencesThe National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
(also available in pdf format) - Curt Stern Papers at the American Philosophical Society