Mariana Federica Wolfner is the Goldwin Smith Professor of

molecular biology Molecular biology is a branch of biology that seeks to understand the molecule, molecular basis of biological activity in and between Cell (biology), cells, including biomolecule, biomolecular synthesis, modification, mechanisms, and interactio ...

and

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 ...

Cornell University Cornell University is a Private university, private Ivy League research university based in Ithaca, New York, United States. The university was co-founded by American philanthropist Ezra Cornell and historian and educator Andrew Dickson W ...

. Her research investigates

sexual conflict Sexual conflict or sexual antagonism occurs when the two sexes have conflicting optimal fitness (biology), fitness strategies concerning reproduction, particularly over the mode and frequency of mating, potentially leading to an evolutionary arms ...

in the fruit fly ''

Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (an insect of the Order (biology), order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly" ...

''. She was elected a member of the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, NGO, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the ...

(NAS) in 2019 in recognition of her distinguished and continuing achievements in original research.

Early life and education

Wolfner became interested in biology as a child. She decided to study at Cornell University because it was well known for genetics. During her undergraduate degree she worked in

Gerald Fink Gerald Ralph Fink (born July 1, 1940) is an American biologist, who was Director of the Whitehead Institute at MIT from 1990 to 2001. He graduated from Amherst College in 1962 and received a Ph.D. from Yale University in 1965, having elucidate ...

's laboratory, studying the control of

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...

s in

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

, and graduated in 1974. She moved to

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 ...

for her graduate degree, where she was a doctoral student in the lab of

David Hogness David Swenson Hogness (November 17, 1925 – December 24, 2019) was an American biochemist, geneticist, and developmental biologist and emeritus professor at the Stanford University School of Medicine in Stanford, California. Life Hogness spent ...

. She was one of the first to use

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 ...

to isolate the genes in ''

Drosophila ''Drosophila'' (), from Ancient Greek δρόσος (''drósos''), meaning "dew", and φίλος (''phílos''), meaning "loving", is a genus of fly, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or p ...

''. Wolfner pioneered the use of

cDNA In genetics, complementary DNA (cDNA) is DNA that was reverse transcribed (via reverse transcriptase) from an RNA (e.g., messenger RNA or microRNA). cDNA exists in both single-stranded and double-stranded forms and in both natural and engin ...

hybridisation to isolate the genes which respond to

ecdysone Ecdysone is a prohormone of the major insect molting hormone 20-hydroxyecdysone, secreted from the prothoracic glands. It is of steroidal structure. Insect molting hormones (ecdysone and its homologues) are generally called ecdysteroids. Ecdy ...

during

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth transformation or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and different ...

Research and career

Wolfner joined

University of California, San Diego The University of California, San Diego (UC San Diego in communications material, formerly and colloquially UCSD) is a public university, public Land-grant university, land-grant research university in San Diego, California, United States. Es ...

for a

postdoctoral 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 ...

fellow A fellow is a title and form of address for distinguished, learned, or skilled individuals in academia, medicine, research, and industry. The exact meaning of the term differs in each field. In learned society, learned or professional society, p ...

ship under the supervision of Bruce Baker. Here she started to study the genes that are involved in sex determination of ''Drosophila''. With Baker, Wolfner cloned the

doublesex ''Doublesex'' (''dsx'') is a gene that is involved in the sex determination system of many insects including the fruit fly ''Drosophila melanogaster''. Sex determination The gene is expressed in both male and female flies and is subject to al ...

gene. Wolfner joined the faculty at Cornell University in 1983. She has explored the mechanisms that are responsible for sex determination and development in ''Drosophila''. Wolfner has identified over two hundred of the drosophila

seminal fluid protein Seminal fluid proteins (SFPs) or accessory gland proteins (Acps) are one of the non-sperm components of semen. In many animals with internal fertilization, males transfer a complex cocktail of proteins in their semen to females during copulation. T ...

s and their influence on physiology and behaviour. She performed genetic ablation to identify the genes that encoded seminal fluid proteins. She found that female drosophila store semen for a while before fertilisation, and become less interested in males after mating. Wolfner found that during mating the seminal fluid proteins that were created in

male accessory gland Male accessory glands (MAG) are the seminal vesicles, prostate gland, and the bulbourethral glands. These glands are found only in mammals. In insects, male accessory glands produce products that mix with the sperm to protect and preserve them, ...

s were transferred to females, and caused postmating changes. She spent two years at the

working on mutant phenotypes in seminal fluid proteins. In her extensive studies of the seminal fluid proteins of ''Drosophila'', Wolfner has uncovered new information about

. She showed that seminal fluid proteins that increase the egg-laying rate of females are beneficial for males, but can reduce the lifespan of the female drosophila. Apc26Aa is one of the seminal fluid proteins that can cause these postmating changes in female drosophila. She found that seminal fluid proteins can act as switches that activate

physiology Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ syst ...

in the mated females. * Wolfner works with Laura Harrington on the identification of seminal fluid proteins in mosquitoes that are responsible for the transmission of the

Zika Zika fever, also known as Zika virus disease or simply Zika, is an infectious disease caused by the Zika virus. Most cases have no symptoms, but when present they are usually mild and can resemble dengue fever. Symptoms may include fever, conju ...

and

dengue virus Dengue virus (DENV) is the cause of dengue fever. It is a mosquito-borne, single positive-stranded RNA virus of the family ''Flaviviridae''; genus '' Flavivirus''. Four serotypes of the virus have been found, and a reported fifth has yet to be ...

es. She also works on the

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...

-to-

embryo An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sp ...

transition, after the

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 ...

is released and before it is activated to begin

embryogenesis An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male ...

. Wolfner demonstrated that the egg-to-embryo transition is not the same in drosophila and mammals. In drosophila, the oocyte is squeezed into the

oviduct The oviduct in vertebrates is the passageway from an ovary. In human females, this is more usually known as the fallopian tube. The eggs travel along the oviduct. These eggs will either be fertilized by spermatozoa to become a zygote, or will dege ...

, whereas in mammals the

sperm Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...

triggers the transition. She showed that the activation process in drosophila involves a spike of

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

, which triggers downstream pathways. She was appointed the Goldwin Smith Professor of Molecular Biology & Genetics in Cornell University in 2013.

Awards and honours

* 2006 Elected a

Fellow of the American Association for the Advancement of Science Fellowship of the American Association for the Advancement of Science (FAAAS) is an honor accorded by the American Association for the Advancement of Science (AAAS) to distinguished persons who are members of the Association. Fellows are elected ...

(FAAAS) * 2012

Kendall S. Carpenter Memorial Award for Distinguished Advising * 2016 Queen's University Al Downe Lecturer * 2017

Entomological Society of America The Entomological Society of America (ESA) was founded in 1889 and today has more than 7,000 members, including educators, extension personnel, consultants, students, researchers, and scientists from agricultural departments, health agencies, ...

Recognition Award in Physiology, Biochemistry and Toxicology * 2018 Genetics Society of America Medal * 2019 Elected a member of the

(NAS)

References

{{DEFAULTSORT:Wolfner, Mariana American women geneticists Cornell University faculty Cornell University alumni American geneticists Members of the United States National Academy of Sciences Fellows of the American Association for the Advancement of Science Stanford University alumni 20th-century American biologists 20th-century American women scientists 21st-century American biologists 21st-century American women scientists Year of birth missing (living people) Living people American women academics