M. Laurance Morse
Encyclopedia
Melvin Laurance Morse (February 23, 1921 - November 7, 2003) was an American microbiologist
and immunologist. He is notable for his co-discovery (with Esther Lederberg
and Joshua Lederberg
) of Specialized Transduction.
After obtaining his PhD from the University of Wisconsin in 1955, Morse went on to study galactosemia
as a Research Associate in Esther Lederberg and Joshua Lederberg's laboratory, and, after 1956, at the University of Colorado School of Medicine.
, the son of Clinton D. Morse and V. Louise Morse. He obtained a B.S. in Microbiology from the University of New Hampshire
in 1944, and an MS in Microbiology from the University of Kentucky
in 1947.
He married Helvise Glessner in 1948.
For four years after completing his Master's program, Morse worked at the Biology Division of Oak Ridge National Laboratory, performing radiation research with Alexander Hollaender
. Morse also investigated the synthesis of nucleic acids in cultures of Escherichia coli with C. E. Carter and, with R. H. Weaver, a technique for identifying cultures by their production of hydrogen sulfide.
In 1951 Morse, his wife and their infant daughter moved to Wisconsin, where he began his doctoral studies in genetics.
Esther Lederberg and Larry Morse discovered that Lambda phage
(first isolated by Esther Lederberg in 1950) could be a heterogenote (a prophage that does not contain the entire lambda prophage, for example, a transductant). This type of recombination event, referred to as specialized transduction, occurs as a result of mistakes in the transition from a virus' lysogenic to lytic cycle. If a virus incorrectly removes itself from the bacterial chromosome, bacterial DNA from either end of the phage DNA may be packaged into the viral capsid.
Esther Lederberg, Larry Morse and others (including Herman Kalckar
, Michael Yarmolinsky, and Yukinori Hirota) went on to do detailed studies of Galactosemia. Specialized transduction was used in these studies for gene mapping.
Papers resulting directly from the collaboration with Esther Lederberg and Joshua Lederberg (M. L. Morse as author or co-author):
Microbiologist
A microbiologist is a scientist who works in the field of microbiology. Microbiologists study organisms called microbes. Microbes can take the form of bacteria, viruses, fungi, and protists...
and immunologist. He is notable for his co-discovery (with Esther Lederberg
Esther Lederberg
Esther Miriam Zimmer Lederberg was an American microbiologist and immunologist and pioneer of bacterial genetics...
and Joshua Lederberg
Joshua Lederberg
Joshua Lederberg ForMemRS was an American molecular biologist known for his work in microbial genetics, artificial intelligence, and the United States space program. He was just 33 years old when he won the 1958 Nobel Prize in Physiology or Medicine for discovering that bacteria can mate and...
) of Specialized Transduction.
After obtaining his PhD from the University of Wisconsin in 1955, Morse went on to study galactosemia
Galactosemia
Galactosemia is a rare genetic metabolic disorder that affects an individual's ability to metabolize the sugar galactose properly. Although the sugar lactose can metabolize to galactose, galactosemia is not related to and should not be confused with lactose intolerance...
as a Research Associate in Esther Lederberg and Joshua Lederberg's laboratory, and, after 1956, at the University of Colorado School of Medicine.
Early years
Larry Morse was born on February 23, 1921, in Hopkinton, MassachusettsHopkinton, Massachusetts
Hopkinton is a town in Middlesex County, Massachusetts, just under 30 miles west and south of Boston. The town is best known as the starting point of the Boston Marathon, held annually on Patriots' Day in April, and as the home of computer storage firm EMC Corporation.For geographic and demographic...
, the son of Clinton D. Morse and V. Louise Morse. He obtained a B.S. in Microbiology from the University of New Hampshire
University of New Hampshire
The University of New Hampshire is a public university in the University System of New Hampshire , United States. The main campus is in Durham, New Hampshire. An additional campus is located in Manchester. With over 15,000 students, UNH is the largest university in New Hampshire. The university is...
in 1944, and an MS in Microbiology from the University of Kentucky
University of Kentucky
The University of Kentucky, also known as UK, is a public co-educational university and is one of the state's two land-grant universities, located in Lexington, Kentucky...
in 1947.
He married Helvise Glessner in 1948.
For four years after completing his Master's program, Morse worked at the Biology Division of Oak Ridge National Laboratory, performing radiation research with Alexander Hollaender
Alexander Hollaender
Alexander Hollaender was one of the world's leading researchers in radiation biology and in genetic mutations. In 1983 he was given the Enrico Fermi Award by the United States Department of Energy for his contributions in founding the science of radiation biology, and for his leadership in...
. Morse also investigated the synthesis of nucleic acids in cultures of Escherichia coli with C. E. Carter and, with R. H. Weaver, a technique for identifying cultures by their production of hydrogen sulfide.
In 1951 Morse, his wife and their infant daughter moved to Wisconsin, where he began his doctoral studies in genetics.
Contributions to microbiology and genetics
Larry Morse spent five years working in the University of Wisconsin-Madison laboratory of Joshua Lederberg and Esther Lederberg: four as a graduate student (before receiving his PhD in Genetics in 1955), and one as a Research Associate.Esther Lederberg and Larry Morse discovered that Lambda phage
Lambda phage
Enterobacteria phage λ is a temperate bacteriophage that infects Escherichia coli.Lambda phage is a virus particle consisting of a head, containing double-stranded linear DNA as its genetic material, and a tail that can have tail fibers. The phage particle recognizes and binds to its host, E...
(first isolated by Esther Lederberg in 1950) could be a heterogenote (a prophage that does not contain the entire lambda prophage, for example, a transductant). This type of recombination event, referred to as specialized transduction, occurs as a result of mistakes in the transition from a virus' lysogenic to lytic cycle. If a virus incorrectly removes itself from the bacterial chromosome, bacterial DNA from either end of the phage DNA may be packaged into the viral capsid.
Esther Lederberg, Larry Morse and others (including Herman Kalckar
Herman Kalckar
Herman Moritz Kalckar was a Danish biochemist who pioneered the study of cellular respiration. Trained as a medical doctor at the University of Copenhagen, Kalckar then conducted research for his Ph. D. in Ejnar Lundsgaard's physiology laboratory, work which helped establish a fundamental...
, Michael Yarmolinsky, and Yukinori Hirota) went on to do detailed studies of Galactosemia. Specialized transduction was used in these studies for gene mapping.
Papers resulting directly from the collaboration with Esther Lederberg and Joshua Lederberg (M. L. Morse as author or co-author):
- "Genetic transduction in Escherichia coli, Doctoral dissertation, University of Wisconsin, 1955
- "Cis-Trans position effect in transduction heterogenotes of Escherichia coli", by Morse, M. L., Genetics 40: 586-587, 1955
- "Transduction in Escherichia coli K-12", by Morse, M. L., E. M. Lederberg, and J. Lederberg, Genetics 41(1): 142-156, Jan., 1956
- "Transductional heterogenotes in Escherichia coli", by Morse, M. L., E. M. Lederberg, and J. Lederberg, Genetics 41(5): 758-779, Sept. 1956
- "Transduction and transformation", by Morse, M. L., and M. L. Alire, Annals of the New York Academy of Sciences, 68(2): 324-334, Oct. 21, 1957
- "Recombination and segregation in Gal heterogenotes showing position effect", by Morse, M. L., Genetics, 44: 529, 1959
- "TRANSDUCTION BY STAPHYLOCOCCAL BACTERIOPHAGE", by Morse, M. L., Proceedings of the National Academy of Sciences USA", 45(5): 722-727, May, 1959
- "FURTHER STUDIES OF SOME GALACTOSE MUTANTS OF e. COLI k-12", by Morse, M. L., Biophysical Society Fifth Annual Meeting (abstract), 1961
- "CHARACTERISTICS OF A STAPHYLOCOCCAL PHAGE CAPABLE OF TRANSDUCTION", by Morse, M. L., Journal of Bacteriology, 83(4): 775-780, April, 1962
- "Mapping studies of galactose mutants of Escherichia coli K-12", by Morse, M. L., Genetics, 45, 1001, 1960 and PNAS, Aug., 1962
- "SPONTANEOUS PRODUCTION OF LAMBDA PARTICLES WITH TRANSDUCING ACTIVITY", by Morse, M. L., Genetics, 47(2): 255-260, February, 1962
- "Galactose Mutants of E. coli not Serving as Recipients in Lambda Transduction", by Morse, M. L., Biophysical Society Sixth Annual Meeting, 1962
- "Reverse Mutation Among Galactose Mutations of E. coli K-12", by Morse, M. L., Bacteria Proceedings (abstract), p. 42, 1962
- "Galactose Mutations of Escherichia Coli K-12 Not Amenable to Lambda Transduction", by Morse, M. L. and J. W. Labelle, Genetics 48(6): 835-840, June, 1963
Professional associations
- American Society for Microbiology
- American Association for the Advancement of Science
External links
- To view the thirty-year correspondence between M. Laurance Morse and Esther M. Lederberg, see http://www.estherlederberg.com/EImages/Archive/ArchiveIndex.html; click the entry for "Morse, M. Laurance".
- Morse Society website: http://www.morsesociety.org
- University of Colorado School of Medicine obituary for M. Laurance Morse: https://www.cu.edu/sg/messages/2708.html