Janet E. Mertz (born 1949) is an American biochemist, molecular biologist, and

cancer Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...

researcher.''American Men and Women of Science'' – Gale. She is currently the Elizabeth McCoy Professor of

Oncology Oncology is a branch of medicine that deals with the study, treatment, diagnosis, and prevention of cancer. A medical professional who practices oncology is an ''oncologist''. The name's Etymology, etymological origin is the Greek word ὄγ ...

in the McArdle Laboratory for Cancer Research at the

University of Wisconsin–Madison The University of Wisconsin–Madison (University of Wisconsin, Wisconsin, UW, UW–Madison, or simply Madison) is a public land-grant research university in Madison, Wisconsin, United States. It was founded in 1848 when Wisconsin achieved st ...

.Janet Mertz's homepage at UW-Madison
/ref> Mertz is best known for disputing

Lawrence Summers Lawrence Henry Summers (born November 30, 1954) is an American economist who served as United States Secretary of the Treasury from 1999 to 2001 and as the director of the National Economic Council from 2009 to 2010. He also served as presiden ...

' 2005 suggestion that women lack the intrinsic aptitude to excel in mathematics at the highest level and for discovering an easy method for joining

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

s from different

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

.Paul Berg, interview by Sally Smith Hughes, 1997, (2000) ''A Stanford Professor's Career in Biochemistry, Science Politics, and the Biotechnology Industry.'' Program in the History of the Biosciences and Biotechnology, Regional Oral History Office, Bancroft Library, University of California, Berkeley
/ref>Doogab Yi (2008) Cancer, Viruses, and Mass Migration: Paul Berg's Venture into Eukaryotic Biology and the Advent of Recombinant DNA Research and Technology, 1967–1980, ''J. History of Biology'' 41:589–636.Errol C. Friedberg (2014) ''A Biography of Paul Berg: The Recombinant DNA Controversy Revisited,'' World Scientific.Doogab Yi (2015) ''The Recombinant University: Genetic Engineering and the Emergence of Stanford Biotechnology,'' University of Chicago Press. This latter finding initiated the era of

genetic engineering Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of Genetic engineering techniques, technologies used to change the genet ...

whose ramifications form the basis of modern

genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian ...

and the

biotechnology Biotechnology is a multidisciplinary field that involves the integration of natural sciences and Engineering Science, engineering sciences in order to achieve the application of organisms and parts thereof for products and services. Specialists ...

industry. After completing bachelor's degrees in biology and electrical engineering at the Massachusetts Institute of Technology, Mertz attended graduate school at

Stanford University Leland Stanford Junior University, commonly referred to as Stanford University, is a Private university, private research university in Stanford, California, United States. It was founded in 1885 by railroad magnate Leland Stanford (the eighth ...

from 1970 to 1975, earning a

Ph.D. A Doctor of Philosophy (PhD, DPhil; or ) is a terminal degree that usually denotes the highest level of academic achievement in a given discipline and is awarded following a course of graduate study and original research. The name of the deg ...

Biochemistry Biochemistry, or biological chemistry, is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, a ...

. Also in the year 1970, Mertz joined

Paul Berg Paul Berg (June 30, 1926 – February 15, 2023) was an American biochemist and professor at Stanford University. He was the recipient of the Nobel Prize in Chemistry in 1980, along with Walter Gilbert and Frederick Sanger. The award recogniz ...

's lab which was located in the biochemistry department at Stanford. Berg said that Mertz was "as smart as all hell." While taking a course held at the

Cold Spring Harbor Laboratory Cold Spring Harbor Laboratory (CSHL) is a private, non-profit institution with research programs focusing on cancer, neuroscience, botany, genomics, and quantitative biology. It is located in Laurel Hollow, New York, in Nassau County, on ...

in summer 1971, she mentioned her plan to grow

mutant In biology, and especially in genetics, a mutant is an organism or a new genetic character arising or resulting from an instance of mutation, which is generally an alteration of the DNA sequence of the genome or chromosome of an organism. It i ...

s of the

oncovirus An oncovirus or oncogenic virus is a virus that can cause cancer. This term originated from studies of acutely transforming retroviruses in the 1950–60s, when the term ''oncornaviruses'' was used to denote their RNA virus origin. With the let ...

SV40 SV40 is an abbreviation for simian vacuolating virus 40 or simian virus 40, a polyomavirus that is found in both monkeys and humans. Like other polyomaviruses, SV40 is a DNA virus that is found to cause tumors in humans and animals, but most ofte ...

, by

molecular cloning Molecular cloning is a set of experimental methods in molecular biology that are used to assemble recombinant DNA molecules and to direct their DNA replication, replication within Host (biology), host organisms. The use of the word ''cloning'' re ...

of them in the human gut

bacterium Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the ...

, ''

E. coli ''Escherichia coli'' ( )Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escherichia'' that is commonly foun ...

''. This event led, initially, to a voluntary moratorium on cloning of viral

oncogene An oncogene is a gene that has the potential to cause cancer. In tumor cells, these genes are often mutated, or expressed at high levels.

s and, later on, the cloning of any DNA that might contain potentially biohazardous materials until theoretical safety concerns could be addressed and guidelines for their safe use could be developed and implemented. In the interim, in collaboration with Ronald W. Davis, Mertz discovered that DNA ends generated by cutting with the EcoRI

restriction enzyme A restriction enzyme, restriction endonuclease, REase, ENase or'' restrictase '' is an enzyme that cleaves DNA into fragments at or near specific recognition sites within molecules known as restriction sites. Restriction enzymes are one class o ...

are "sticky", permitting any two such DNAs to be readily "recombined". Using this discovery, in June 1972 she created the first

recombinant DNA Recombinant DNA (rDNA) molecules are DNA molecules formed by laboratory methods of genetic recombination (such as molecular cloning) that bring together genetic material from multiple sources, creating sequences that would not otherwise be fo ...

that could have been cloned in bacteria.Janet E. Mertz & Ronald W. Davis (1972) Cleavage of DNA by R1 restriction endonuclease generates cohesive ends. ''Proc Natl Acad Sci USA'' 69:3370–3374.Janet E. Mertz's laboratory notebooks, 1971–1973
available as part of the Paul Berg Papers collection, 1953-1986, housed in the Department of Special Collections and University Archives at Stanford University Libraries.Janet E. Mertz, Ronald W. Davis, and Paul Berg (1972) Characterization of the cleavage site of the RI restriction enzyme, abstract presented on August 16, 1972 at the ''4th Annual Tumor Virus Meeting'', Cold Spring Harbor Laboratory, NY. Her success with this project contributed to her thesis adviser,

, receiving the 1980

Nobel Prize in Chemistry The Nobel Prize in Chemistry () is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outst ...

. The Nobel Prize in Chemistry 1980
/ref> However, Mertz did not proceed with this cloning because of the moratorium in place at that time, leaving it for

Herbert Boyer Herbert Wayne "Herb" Boyer (born July 10, 1936) is an American biotechnologist, researcher and entrepreneur in biotechnology. Along with Stanley N. Cohen and Paul Berg, he discovered recombinant DNA, a method to coax bacteria into producing for ...

, Stanley N. Cohen and their colleagues to prove in 1973 that recombinant DNAs made by this method can actually self-replicate in bacteria.Stanley Cohen et al. (1973) Construction of biologically functional bacterial plasmids in vitro. ''Proc Natl Acad Sci USA'' 70:3240–3244. Thus, most of Mertz's Ph.D. thesis centered, instead, around developing other ways to create, select, and grow mutants of SV40 for studying this virus' functions and so it could be used as the first eukaryotic

cloning vector A cloning vector is a small piece of DNA that can be stably maintained in an organism, and into which a foreign DNA fragment can be inserted for cloning purposes. The cloning vector may be DNA taken from a virus, the cell of a higher organism, o ...

. Paul Berg (1980) Nobel lecture 1980: Dissections and reconstructions of genes and chromosomes. ''Nobel Lectures: Chemistry 1971-1980'', World Scientific
/ref> The US

Patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling discl ...

4,237,224, "Process for Producing Biologically Functional Molecular Chimeras", which generated over $250 million in licensing and royalty income, listed only Boyer and Cohen as co-inventors.Sally S. Hughes (2001) Making dollars out of DNA: the first major patent in biotechnology and the commercialization of molecular biology 1974–1980. ''Isis'' 92:541–575. Some have questioned whether these patents were valid given the earlier publications by Peter Lobban and A. Dale KaiserPeter E. Lobban (1972) ''An Enzymatic Method for End-to-end Joining of DNA Molecules.'' Ph.D. dissertation, Stanford University.Peter E. Lobban & A. Dale Kaiser (1973) Enzymatic end-to-end joining of DNA molecules. ''J Mol Biol'' 78: 453-471. and the Berg laboratoryDavid A. Jackson, Robert H. Symons, and Paul Berg (1972) Biochemical method for inserting new genetic information into DNA of simian virus 40. ''Proc Natl Acad Sci USA'' 69:2904–2909. that were already in the

public domain The public domain (PD) consists of all the creative work to which no Exclusive exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly Waiver, waived, or may be inapplicable. Because no one holds ...

at the time this application was filed in November 1974. Stephanie Chen (2014) ''Authorship and inventorship: An analysis of publishing and patenting norms and their consequences at American universities.'' Senior Thesis, Duke University
/ref>

Later research and academic career

Mertz spent 15 months as a

postdoctoral researcher 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 ...

at the Medical Research Council. In collaboration with

John B. Gurdon Sir John Bertrand Gurdon (born 2 October 1933) is a British developmental biologist, best known for his pioneering research in nuclear transplantation and cloning. Awarded the Lasker Award in 2009, in 2012, he and Shinya Yamanaka were join ...

and

Edward M. De Robertis Edward Michael De Robertis (born June 6, 1947) is an American embryologist and Professor at the University of California, Los Angeles. His work has contributed to the finding of conserved molecular processes of embryonic inductions that result in ...

, she showed that biological

macromolecule A macromolecule is a "molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass." Polymers are physi ...

s injected into frog

oocyte An oocyte (, oöcyte, or ovocyte) is a female gametocyte or germ cell involved in reproduction. In other words, it is an immature ovum, or egg cell. An oocyte is produced in a female fetus in the ovary during female gametogenesis. The female ger ...

s are properly used, providing the first way to study many aspects of

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

expression in a higher

eukaryote 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 ...

.Janet E. Mertz & John B. Gurdon (1977) Purified DNAs are transcribed after microinjection into Xenopus oocytes. ''Proc Natl Acad Sci USA'' 74:1502-1506.Edward M. De Robertis & Janet E. Mertz (1977) Coupled transcription-translation of DNA injected into Xenopus oocytes. ''Cell'' 12:175-182. Mertz has been a member of the University of Wisconsin - Madison faculty since 1976. Her laboratory studies regulation of expression of the genes of the DNA oncoviruses SV40,

hepatitis B virus Hepatitis B virus (HBV) is a partially double-stranded DNA virus, a species of the genus '' Orthohepadnavirus'' and a member of the '' Hepadnaviridae'' family of viruses. This virus causes the disease hepatitis B. Classification Hepatitis B ...

, and

Epstein–Barr virus The Epstein–Barr virus (EBV), also known as human herpesvirus 4 (HHV-4), is one of the nine known Herpesviridae#Human herpesvirus types, human herpesvirus types in the Herpesviridae, herpes family, and is one of the most common viruses in ...

and the roles the

nuclear receptor In the field of molecular biology, nuclear receptors are a class of proteins responsible for sensing steroids, thyroid hormones, vitamins, and certain other molecules. These intracellular receptors work with other proteins to regulate the ex ...

estrogen-related receptor α plays in

breast cancer Breast cancer is a cancer that develops from breast tissue. Signs of breast cancer may include a Breast lump, lump in the breast, a change in breast shape, dimpling of the skin, Milk-rejection sign, milk rejection, fluid coming from the nipp ...

and regulating the activities of

estrogen receptor Estrogen receptors (ERs) are proteins found in cell (biology), cells that function as receptor (biochemistry), receptors for the hormone estrogen (17β-estradiol). There are two main classes of ERs. The first includes the intracellular estrogen ...

α.

References

External links

* {{DEFAULTSORT:Mertz, Janet E. 1949 births American women biochemists American cancer researchers Fellows of the American Association for the Advancement of Science History of biotechnology Living people Massachusetts Institute of Technology School of Science alumni Stanford University alumni American molecular biologists Scientists from the Bronx MIT School of Engineering alumni 21st-century American women