Ernst Freese | |
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Born | September 27, 1925 |
Died | March 30, 1990 64) | (aged
Alma mater | University of Göttingen |
Known for | Molecular biology research |
Spouse(s) | Elisabeth Bautz |
Children |
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Dr. Ernst Freese (September 27, 1925 - March 30, 1990) was a molecular biologist who worked on the mechanism of mutations in DNA. From 1962 until his death he was Chief of the National Institute of Neurological Disorders and Stroke (NINDS) Laboratory of Molecular Biology at the National Institutes of Health (NIH). Ernst Freese's scientific career started in theoretical particle physics and later moved to molecular biology where he contributed to early genetics research.
Ernst Freese began his career as a student of physics with Werner Heisenberg at the University of Göttingen, Göttingen, Germany, where Freese received his PhD in 1953 in work in theoretical particle physics. He came to the United States in 1954 to work as a postdoctoral fellow with Enrico Fermi at the University of Chicago. He started his career in biology at Max Delbrück's laboratory at the California Institute of Technology in 1955. He held research positions at the University of Cologne (1956-1957) and Harvard University (1957-1959), where he worked with James Watson. Freese joined the University of Wisconsin as an Associate Professor of genetics in 1959 and established the university's first molecular biology program. In 1962 he moved to the National Institutes of Health (NIH) as Chief of the National Institute of Neurological Disorders and Stroke (NINDS) Laboratory of Molecular Biology. He held this position until his death. [1] The other laboratory chiefs included Marshall Warren Nirenberg and Daniel Carleton Gajdusek. Freese was also the Director of the Basic Neurosciences Program at NINDS from 1987.
Freese was interested in the molecular mechanism of mutations and determined the difference between spontaneous and chemical mutations by using T4 phage. In 1959 he coined the terms "transitions" and "transversions" to categorize different types of point mutations. [2] [3] Point mutations, often caused by chemicals or malfunction of DNA replication, exchange a single nucleotide for another. Most common is the transition that exchanges a purine for a purine (A ↔ G) or a pyrimidine for a pyrimidine, (C ↔ T).
Freese's research also included microbial differentiation and molecular neurobiology. He studied the effect of lipophilic acids on the growth and differentiation of bacteria. Freese's laboratory worked on the metabolic control of sporulation and germination of Bacillus subtilis bacteria. He identified the key metabolite for ignition of sporulation: a decrease of GTP. Freese was cofounder of the Environmental Mutagen Society and served as its president for two years. In 1971, he organized the first comprehensive conference focused on the prospects of gene therapy through the John E. Fogarty International Center. [4] His laboratory identified certain compounds as mutagenic and he was instrumental in banning the use of certain pesticides and food additives. Later in his career, as a NIH administrator, he provided the initial support to J. Craig Venter to initiate his program to sequence the human genome. [5] His laboratory first sequenced GFAP (glial fibrillary acidic protein), and helped to elucidate its role in neural structure and development. [6] Throughout his career, he trained dozens of postdoctoral research fellows. He received the Alexander von Humboldt Prize in 1983.
After meeting her at Caltech, Freese married his fellow postdoctoral fellow, Dr. Elisabeth Bautz, in 1956, and together they had two children, Katherine Freese [7] and Andrew Freese. After the death of Elisabeth, he married Katherine Bick, Ph.D. in 1985, who was the Deputy Director of Extramural Research for the National Institutes of Health.
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA and RNA. Dictated by specific hydrogen bonding patterns, "Watson–Crick" base pairs allow the DNA helix to maintain a regular helical structure that is subtly dependent on its nucleotide sequence. The complementary nature of this based-paired structure provides a redundant copy of the genetic information encoded within each strand of DNA. The regular structure and data redundancy provided by the DNA double helix make DNA well suited to the storage of genetic information, while base-pairing between DNA and incoming nucleotides provides the mechanism through which DNA polymerase replicates DNA and RNA polymerase transcribes DNA into RNA. Many DNA-binding proteins can recognize specific base-pairing patterns that identify particular regulatory regions of genes.
James Dewey Watson is an American molecular biologist, geneticist, and zoologist. In 1953, he co-authored with Francis Crick the academic paper proposing the double helix structure of the DNA molecule. Watson, Crick and Maurice Wilkins were awarded the 1962 Nobel Prize in Physiology or Medicine "for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material". In subsequent years, it has been recognized that Watson and his colleagues did not properly attribute colleague Rosalind Franklin for her contributions to the discovery of the double helix structure.
Molecular biology is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including molecular synthesis, modification, mechanisms, and interactions. The study of chemical and physical structure of biological macromolecules is known as molecular biology.
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosis, or meiosis or other types of damage to DNA, which then may undergo error-prone repair, cause an error during other forms of repair, or cause an error during replication. Mutations may also result from insertion or deletion of segments of DNA due to mobile genetic elements.
Nucleic acids are biopolymers, macromolecules, essential to all known forms of life. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). If the sugar is ribose, the polymer is RNA; if the sugar is the ribose derivative deoxyribose, the polymer is DNA.
Thymidine, also known as deoxythymidine, deoxyribosylthymine, or thymine deoxyriboside, is a pyrimidine deoxynucleoside. Deoxythymidine is the DNA nucleoside T, which pairs with deoxyadenosine (A) in double-stranded DNA. In cell biology it is used to synchronize the cells in G1/early S phase. The prefix deoxy- is often left out since there are no precursors of thymine nucleotides involved in RNA synthesis.
Max Ludwig Henning Delbrück was a German–American biophysicist who participated in launching the molecular biology research program in the late 1930s. He stimulated physical scientists' interest into biology, especially as to basic research to physically explain genes, mysterious at the time. Formed in 1945 and led by Delbrück along with Salvador Luria and Alfred Hershey, the Phage Group made substantial headway unraveling important aspects of genetics. The three shared the 1969 Nobel Prize in Physiology or Medicine "for their discoveries concerning the replication mechanism and the genetic structure of viruses". He was the first physicist to predict what is now called Delbrück scattering.
The coding region of a gene, also known as the coding sequence(CDS), is the portion of a gene's DNA or RNA that codes for protein. Studying the length, composition, regulation, splicing, structures, and functions of coding regions compared to non-coding regions over different species and time periods can provide a significant amount of important information regarding gene organization and evolution of prokaryotes and eukaryotes. This can further assist in mapping the human genome and developing gene therapy.
A DNA polymerase is a member of a family of enzymes that catalyze the synthesis of DNA molecules from nucleoside triphosphates, the molecular precursors of DNA. These enzymes are essential for DNA replication and usually work in groups to create two identical DNA duplexes from a single original DNA duplex. During this process, DNA polymerase "reads" the existing DNA strands to create two new strands that match the existing ones. These enzymes catalyze the chemical reaction
A point mutation is a genetic mutation where a single nucleotide base is changed, inserted or deleted from a DNA or RNA sequence of an organism's genome. Point mutations have a variety of effects on the downstream protein product—consequences that are moderately predictable based upon the specifics of the mutation. These consequences can range from no effect to deleterious effects, with regard to protein production, composition, and function.
The Nirenberg and Matthaei experiment was a scientific experiment performed in May 1961 by Marshall W. Nirenberg and his post-doctoral fellow, J. Heinrich Matthaei, at the National Institutes of Health (NIH). The experiment deciphered the first of the 64 triplet codons in the genetic code by using nucleic acid homopolymers to translate specific amino acids.
Marshall Warren Nirenberg was an American biochemist and geneticist. He shared a Nobel Prize in Physiology or Medicine in 1968 with Har Gobind Khorana and Robert W. Holley for "breaking the genetic code" and describing how it operates in protein synthesis. In the same year, together with Har Gobind Khorana, he was awarded the Louisa Gross Horwitz Prize from Columbia University.
Glial fibrillary acidic protein (GFAP) is a protein that is encoded by the GFAP gene in humans. It is a type III intermediate filament (IF) protein that is expressed by numerous cell types of the central nervous system (CNS), including astrocytes and ependymal cells during development. GFAP has also been found to be expressed in glomeruli and peritubular fibroblasts taken from rat kidneys, Leydig cells of the testis in both hamsters and humans, human keratinocytes, human osteocytes and chondrocytes and stellate cells of the pancreas and liver in rats.
Franklin (Frank) William Stahl is an American molecular biologist and geneticist. With Matthew Meselson, Stahl conducted the famous Meselson-Stahl experiment showing that DNA is replicated by a semiconservative mechanism, meaning that each strand of the DNA serves as a template for production of a new strand.
Sir John Ernest Walker is a British chemist who won the Nobel Prize in Chemistry in 1997. As of 2015 Walker is Emeritus Director and Professor at the MRC Mitochondrial Biology Unit in Cambridge, and a Fellow of Sidney Sussex College, Cambridge.
The phage group was an informal network of biologists centered on Max Delbrück that contributed heavily to bacterial genetics and the origins of molecular biology in the mid-20th century. The phage group takes its name from bacteriophages, the bacteria-infecting viruses that the group used as experimental model organisms. In addition to Delbrück, important scientists associated with the phage group include: Salvador Luria, Alfred Hershey, Seymour Benzer, Charles Steinberg, Gunther Stent, James D. Watson, Frank Stahl, and Renato Dulbecco.
John W. Drake (1932-2020) was an American microbiologist and geneticist, working for over half a century in the field of mutagenesis and DNA repair.
Jean-Jacques Weigle was a Swiss molecular biologist at Caltech and formerly a physicist at the University of Geneva from 1931 to 1948. He is known for his major contributions on field of bacteriophage λ research, focused on the interactions between those viruses and their E. coli hosts.
Valery Nikolayevich Soyfer, born in 1936 in Gorky is a Russian-American biophysicist, molecular geneticist, historian of science, human rights advocate, and humanitarian.
Nat L. Sternberg was an American molecular biologist and bacteriophage researcher, particularly known for his work on DNA recombination and the phage P1.