Berg, Paul (1926-), an American biochemist and molecular biologist, has been at the forefront of genetic engineering, both as an inventor of a pioneering procedure and as an advocate concerned about the risks of genetic research.
Berg developed recombinant DNA techniques, which allow scientists to splice DNA from different organisms and reeombine them. This discovery has proven valuable to scientific research and in a number of commercial applications including medicine, industry, and agriculture. For his studies of recombinant DNA, Berg shared the 1980 Nobel Prize in chemistry with American Walter Gilbert and Frederick Sanger of the United Kingdom.
Berg was one of three sons born to Harry and Sarah (Brodsky) Berg. He grew up in Brooklyn, New York, where he attended public schools. A bright student, he participated in a program that covered two years of junior high school work in one year. He credits the books Arrowsmith by Sinclair Lewis and Microbe Hunters by Paul de Kruif for sparking his interest in science. Another important influence was that of Sophie Wolfe, a woman who oversaw the demonstration lab at the high school and served as adviser to the science club.
After graduating from Abraham Lincoln High School in 1943, Berg enrolled at Pennsylvania State University. His education was put on hold while he served in the U.S. Navy from 1943 to 1946. He resumed his studies at Penn State and received a degree in biochemistry in 1948. He did his graduate work in biochemistry at Western “Reserve University (now Case Western Reserve University) in Cleveland, Ohio, as a National Institutes of Health fellow, earning his Ph.D. in 1952. He then completed a year of postdoctoral training at the Institute of Cytophysiology in Copenhagen, Denmark. Following that, he studied with biochemist Arthur Kornberg at Washington University in St. Louis, Missouri, where he was named assistant professor of microbiology in 1955. Berg left St. Louis in 1959 to join the faculty at the School of Medicine at Stanford University in Palo Alto, California, as a professor of biochemistry. In 1970, he was appointed Willson Professor of Biochemistry, and, from 1969 to 1974, he served as chairman of the department of biochemistry.
During the 1950's, Berg's research focused on the formation of protein in cells. While working at Washington University, he became familiar with the roles of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA contains the genetic coding to direct the formation, growth, and reproduction of organisms and cells. It is composed of small linked units, called nucleotides, which in turn link to other nucleotides to form thin, chain-like molecules called polynucleotides. RNA is similar in structure to DNA. RNA carries the instructions for protein building from the DNA to the amino acids. A specific type of RNA, known as transfer RNA or tRNA, ensures that amino acids are in the correct position for protein assembly. In 1956, Berg isolated a tRNA that is specific to the amino acid methionine. His work helped to clarify the role tRNA plays in protein assembly
Berg next turned his attention to the study of genes. Genes determine the characteristics that are passed down from one generation to the next. Genes consist essentially of DNA. Berg wanted to examine the structure and function of mammalian genes. In the late 1960's, he began studying the genes of a monkey virus, known as SV40. Berg began to realize that combining DNA from different species could be a powerful research tool. This method would allow him to isolate a gene and study its properties without interference from its usual, neighboring genes.
For his recombinant DNA, Berg combined the DNA of SV40 with a type of E. coli virus that was well understood. These two organisms would not interact in nature, and to make them interact in the lab, Berg used restriction enzymes. These enzymes allowed Berg to cut the DNA strands at specific locations and then recombine the DNA portions. This new technique was seminal but not without risk. Berg worried that dangerous viruses or bacteria could be introduced into the human population. He voluntarily stopped his DNA recombinant experiments and worked on developing other techniques for studying SV40.
In 1974, Berg wrote a letter, which was published in Science, expressing his concern and that of other scientists regarding genetic research. At the time, Berg was the chairman of the Committee on Recombinant DNA Molecules Assembly of Life Sciences of the National Academy of Sciences. The letter asked for an international meeting of scientists to discuss how to proceed with this type of research. In February 1975, a meeting of 100 scientists representing 16 countries took place in Pacific Grove, California. Over the course of four days, the group developed guidelines that covered safety measures for laboratory study and professional standards. These guidelines were incorporated into federal regulations, as published by the National Institutes of Health in 1976. Over time, as scientists have become more comfortable with genetic research, many of the regulations have been lessened or eliminated except for those that deal with the most hazardous organisms.
Since winning the Nobel Prize in chemistry in 1980, Berg has continued investigating mammalian genes and is studying the molecular biology of HIV-1. He is a professor ementus of biochemistry at Stanford University and chairman of the public-policy committee of the American Society for Cell Biology. He has also been outspoken on his support of stem cell research, which could hold the key to curing illnesses such as juvenile diabetes and Parkinson's disease. The cells come from human embryos that which were conceived in fertility clinics and slated to be discarded. The research has drawn protests from antiabortion groups. Berg disagrees with opponents who feel such research is immoral and states that the potential to save human lives is highly moral.
Berg has been active with a number of institutions. He served as director of the Beckman Center for Molecular and Genetic Medicine and was a nonresident fellow of the Salk Institute. He sat on the advisory board of the Jane Coffin Childs Foundation for a decade and, from 1984 to 1990, he was the chair of the scientific advisory committee of the Whitehead Institute at Massachusetts Institute of Technology.
In 1991, he agreed to serve on the national advisory committee of the Human Genome Project, and, in February 2001, he signed a petition along with 79 other Nobel laureates asking President George W. Bush to allow federal funding for embryonic stem cell research.
In addition to the Nobel Prize in chemistry. Berg's pioneering work has earned him numerous other honors and awards, including the Eli Lilly Prize of the American Chemical Society (1959), California Scientist of the Year (1963), the V.D. Mattia Award of the Roche Institute of Molecular Biology (1972), the Sarasota medical awards for achievement and excellence (1979), the New York Academy of Sciences Award (1980), and the National Medal of Science (1983). He holds a membership in the National Academy of Sciences, the American Society for Cell Biology, and the American Academy of Arts and Sciences. In addition, he has received honorary degrees from the University of Rochester and Yale University.
In 1947, Berg married Mildred Levy. The couple has a son, John.