Barbara McClintock (June 16, 1902 – September 2, 1992) was an American scientist andcytogeneticist who was awarded the 1983Nobel Prize in Physiology or Medicine. McClintock received her PhD inbotany fromCornell University in 1927. There she started her career as the leader of the development ofmaize cytogenetics, the focus of her research for the rest of her life. From the late 1920s, McClintock studiedchromosomes and how they change during reproduction in maize. She developed the technique for visualizing maize chromosomes and used microscopic analysis to demonstrate many fundamental genetic ideas. One of those ideas was the notion ofgenetic recombination bycrossing-over duringmeiosis—a mechanism by which chromosomes exchange information. She is often erroneously credited with producing the firstgenetic map for maize, linking regions of the chromosome to physical traits. She demonstrated the role of thetelomere andcentromere, regions of the chromosome that are important in the conservation ofgenetic information. She was recognized as among the best in the field, awarded prestigious fellowships, and elected a member of theNational Academy of Sciences in 1944.
During the 1940s and 1950s, McClintock discoveredtransposons and used it to demonstrate thatgenes are responsible for turning physical characteristics on and off. She developed theories to explain the suppression and expression of genetic information from one generation of maize plants to the next. Due to skepticism of her research and its implications, she stopped publishing her data in 1953.
Later, she made an extensive study of the cytogenetics andethnobotany of maizeraces from South America. McClintock's research became well understood in the 1960s and 1970s, as other scientists confirmed the mechanisms of genetic change andprotein expression that she had demonstrated in her maize research in the 1940s and 1950s. Awards and recognition for her contributions to the field followed, including the Nobel Prize in Physiology or Medicine, awarded to her in 1983 for the discovery ofgenetic transposition; as of 2025, she remains the only woman who has received an unshared Nobel Prize in that category.[2]
McClintock children, from left to right: Mignon, Malcolm Rider "Tom", Barbara and MarjorieMcClintock family, from left to right: Mignon, Tom, Barbara, Marjorie and Sara (at the piano)
Barbara McClintock was bornEleanor McClintock on June 16, 1902, inHartford, Connecticut,[3][4] the third of four children born to homeopathic physician Thomas Henry McClintock and Sara Handy McClintock.[5] Thomas McClintock was the child of British immigrants. Marjorie, the oldest child, was born in October 1898; Mignon, the second daughter, was born in November 1900. The youngest, Malcolm Rider (called Tom), was born 18 months after Barbara. When she was a young girl, her parents determined thatEleanor, a "feminine" and "delicate" name, was not appropriate for her, and choseBarbara instead.[4][6] McClintock was an independent child beginning at a very young age, a trait she later identified as her "capacity to be alone". From the age of three until she began school, McClintock lived with an aunt and uncle in Brooklyn, New York, in order to reduce the financial burden on her parents while her father established his medical practice. She was described as a solitary and independent child. She was close to her father, but had a difficult relationship with her mother, tension that began when she was young.[4][6]
The McClintock family moved to Brooklyn in 1908 and McClintock completed her secondary education there atErasmus Hall High School;[6][7] she graduated in 1919.[8] She discovered her love of science and reaffirmed her solitary personality during high school.[4] She wanted to continue her studies atCornell University's College of Agriculture. Her mother resisted sending McClintock to college for fear that she would be unmarriageable, a common attitude at the time.[6] McClintock was almost prevented from starting college, but her father allowed her to just before registration began, and she matriculated at Cornell in 1919.[9][10]
McClintock began her studies at Cornell'sCollege of Agriculture in 1919. There, she participated instudent government and was invited to join asorority, but later broke her sorority pledge.[11] Instead, McClintock took up music, specificallyjazz. She studiedbotany, receiving aBSc in 1923.[9] Her interest in genetics began when she took her first course in that field in 1921. The course was based on a similar one offered at Harvard University, and was taught byC. B. Hutchison, a plant breeder and geneticist.[12][13][14] Hutchison was impressed by McClintock's interest, and telephoned to invite her to participate in the graduate genetics course at Cornell in 1922. McClintock pointed to Hutchison's invitation as a catalyst for her interest in genetics: "Obviously, this telephone call cast the die for my future. I remained with genetics thereafter."[15] Although it has been reported that women could not major in genetics at Cornell, and therefore her MS and PhD—earned in 1925 and 1927, respectively—were officially awarded in botany, recent research has revealed that women were permitted to earn graduate degrees in Cornell's Plant Breeding Department during the time that McClintock was a student at Cornell.[16][17]
During her graduate studies and postgraduate appointment as a botany instructor, McClintock was instrumental in assembling a group that studied the new field ofcytogenetics in maize. This group brought together plant breeders and cytologists, and includedMarcus Rhoades, futureNobel laureateGeorge Beadle, andHarriet Creighton.[18][19][20]Rollins A. Emerson, head of the Plant Breeding Department, supported these efforts, although he was not a cytologist himself.[21][22][23]
McClintock's cytogenetic research focused on developing ways to visualize and characterize maize chromosomes. This particular part of her work influenced a generation of students, as it was included in most textbooks. She also developed a technique usingcarmine staining to visualize maize chromosomes, and showed for the first time the morphology of the 10 maize chromosomes. This discovery was made because she observed cells from themicrospore as opposed to theroot tip.[21][26][23] By studying the morphology of the chromosomes, McClintock was able tolink specific chromosome groups of traits that were inherited together.[27] Marcus Rhoades noted that McClintock's 1929Genetics paper on the characterization oftriploid maize chromosomes triggered scientific interest in maize cytogenetics, and attributed to her 10 of the 17 significant advances in the field that were made by Cornell scientists between 1929 and 1935.[28]
In 1930, McClintock was the first person to describe the cross-shaped interaction of homologous chromosomes duringmeiosis. The following year, McClintock and Creighton proved the link betweenchromosomal crossover during meiosis and the recombination of genetic traits.[27][29][30] They observed how the recombination of chromosomes seen under a microscope correlated with new traits.[20][31] Until this point, it had only been hypothesized thatgenetic recombination could occur during meiosis, although it had not been shown genetically.[20] It is often reported that McClintock published the first genetic map for maize in 1931, showing the order of three genes on maize chromosome 9;[32] however, it was her genetics professor C. B. Hutchison who has published the first genetic linkage maps for Chromosome 9 in 1921 and 1922.[33] Her chromosome map showed that the arrangement of genes was consistent with the linkage map published by Hutchison in 1921.[34] This information provided necessary data for the crossing-over study she published with Creighton;[29] they also showed that crossing-over occurs insister chromatids as well ashomologous chromosomes.[35] In 1938, she produced a cytogenetic analysis of thecentromere, describing the organization and function of the centromere, as well as the fact that it can divide.[27]
McClintock's breakthrough publications, and support from her colleagues, led to her being awarded several postdoctoral fellowships from theNational Research Council. This funding allowed her to continue to study genetics at Cornell, theUniversity of Missouri, and theCalifornia Institute of Technology, where she worked with E. G. Anderson.[16][35] During the summers of 1931 and 1932, she worked at the University of Missouri with geneticistLewis Stadler, who introduced her to the use ofX-rays as amutagen. Exposure to X-rays can increase the rate of mutation above the natural background level, making it a powerful research tool for genetics. Through her work with X-ray-mutagenized maize, she identifiedring chromosomes, which form when the ends of a single chromosome fuse together after radiation damage.[36] McClintock found the first ring chromosome in maize in 1931, but the first ring chromosome was first reported by Michael Navashin, who she cited in her first study with Stadler.[37] From this evidence, McClintock hypothesized that there must be a structure on the chromosome tip that would normally ensure stability. She showed that the loss of ring-chromosomes at meiosis causedvariegation in maize foliage in generations subsequent to irradiation resulting from chromosomal deletion.[27] During this period, she demonstrated the presence of thenucleolus organizer region on a region on maize chromosome 6, which is required for the assembly of thenucleolus.[27][35][38] In 1933, she established that cells can be damaged whennonhomologous recombination occurs.[27][39] During this same period, McClintock hypothesized that the tips of chromosomes are protected bytelomeres.[40]
McClintock received a fellowship from theGuggenheim Foundation that made possible six months of training in Germany during 1933 and 1934.[36] She had planned to work withCurt Stern, who had demonstrated crossing-over inDrosophila just weeks after McClintock and Creighton had done so; however, Stern emigrated to the United States. Instead, she worked with geneticistRichard B. Goldschmidt, who was a director of the Kaiser Wilhelm Institute for Biology in Berlin.[6][41] She left Germany early amidst mounting political tension in Europe, returned to Cornell, but found that the university would not hire a woman professor.[42] Legends such as the one cited here are based on undocumented evidence. Kass 2024 has evidence that McClintock worked at Cornell on her return to Cornell after spending only 5 months in Germany. Emerson hired her as his assistant in the Department of Plant Breeding where McClintock conducted independent research which led to a job offer as an assistant professor at the University of Missouri.[43] In 1936, she accepted an Assistant Professorship offered to her by Lewis Stadler in the Department of Botany at the University of Missouri inColumbia.[44][45] While still at Cornell, she was supported by a two-yearRockefeller Foundation grant obtained for her through Emerson's efforts.[36]
During her time at Missouri, McClintock expanded her research on the effect of X-rays on maize cytogenetics. McClintock observed the breakage and fusion of chromosomes in irradiated maize cells. She was also able to show that, in some plants, spontaneous chromosome breakage occurred in the cells of the endosperm. Over the course ofmitosis, she observed that the ends of broken chromatids were rejoined after the chromosomereplication.[46] In theanaphase of mitosis, the broken chromosomes formed a chromatid bridge, which was broken when the chromatids moved towards the cell poles. The broken ends were rejoined in theinterphase of the next mitosis, and the cycle was repeated, causing massive mutation, which she could detect as variegation in the endosperm.[47] Thisbreakage–rejoining–bridge cycle was a key cytogenetic discovery for several reasons.[46] First, it showed that the rejoining of chromosomes was not a random event, and second, it demonstrated a source of large-scale mutation. For this reason, it remains an area of interest in cancer research today.[48]
Although her research was progressing at Missouri, McClintock was not satisfied with her position at the university. She recalled being excluded from faculty meetings, and was not made aware of positions available at other institutions.[6] In 1940, she wrote to Charles Burnham, "I have decided that I must look for another job. As far as I can make out, there is nothing more for me here. I am an assistant professor at $3,000 and I feel sure that that is the limit for me."[49][46] Initially, McClintock's position was created especially for her by Stadler, and might have depended on his presence at the university.[16][44] McClintock believed she would not gaintenure at Missouri, even though according to some accounts, she knew she would be offered a promotion from Missouri in the spring of 1942.[50] Recent evidence reveals that McClintock more likely decided to leave Missouri because she had lost trust in her employer and in the university administration, after discovering that her job would be in jeopardy if Stadler were to leave forCaltech, as he had considered doing. The university's retaliation against Stadler amplified her sentiments.[16][51]
In early 1941, she took a leave of absence from Missouri in hopes of finding a position elsewhere. She accepted a visiting professorship atColumbia University, where her former Cornell colleague Marcus Rhoades was a professor. Rhoades also offered to share his research field at Cold Spring Harbor on Long Island. In December 1941, she was offered a temporary research position byMilislav Demerec, the newly appointed acting director of theCarnegie Institution of Washington's Department of Genetics atCold Spring Harbor Laboratory. Although hesitant to make a long-term commitment, McClintock accepted the invitation and became a permanent member of the staff in 1943.[52][53]
After her year-long temporary appointment, McClintock accepted a full-time research position atCold Spring Harbor Laboratory. There, she was highly productive and continued her work with the breakage-fusion-bridge cycle, using it to substitute for X-rays as a tool for mapping new genes. In 1944, in recognition of her prominence in the field of genetics during this period, McClintock was elected to theNational Academy of Sciences—only the third woman to be elected. The following year she became the first female president of theGenetics Society of America;[3] she had been elected its vice-president in 1939.[45] In 1944 she undertook a cytogenetic analysis ofNeurospora crassa at the suggestion of George Beadle, who used the fungus to demonstrate the one gene–one enzyme relationship. He invited her toStanford to undertake the study. She successfully described the number of chromosomes, orkaryotype, ofN. crassa and described the entire life cycle of the species. Beadle said, "Barbara, in two months at Stanford, did more to clean up the cytology ofNeurospora than all other cytological geneticists had done in all previous time on all forms of mold."[54]N. crassa has since become amodel species for classical genetic analysis.[55][56]
The relationship ofAc/Ds in the control of the elements and mosaic color of maize. The seed in 10 is colorless; there is noAc element present, andDs inhibits the synthesis of colored pigments calledanthocyanins. In 11 to 13, one copy ofAc is present;Ds can move, and some anthocyanin is produced, creating a mosaic pattern. In the kernel in panel 14 there are twoAc elements, and in panel 15 there are three.
In the summer of 1944 at Cold Spring Harbor Laboratory, McClintock began systematic studies on the mechanisms of themosaic color patterns of maize seed and the unstableinheritance of this mosaicism.[57] She identified two newdominant and interacting genetic loci that she namedDissociation (Ds) andActivator (Ac). She found that theDissociation did not just dissociate or cause the chromosome to break, it also had a variety of effects on neighboring genes when theActivator was also present, which included making certain stable mutations unstable. In early 1948, she made the surprising discovery that bothDissociation andActivator could transpose, or change position, on the chromosome.[58][59][60][61]
She observed the effects of the transposition ofAc andDs by the changing patterns of coloration in maize kernels over generations of controlled crosses, and described the relationship between the twoloci through intricate microscopic analysis.[62][63] She concluded thatAc controls the transposition of theDs from chromosome 9, and that the movement ofDs is accompanied by the breakage of the chromosome.[61] WhenDs moves, thealeurone-color gene is released from the suppressing effect of theDs and transformed into the active form, which initiates the pigment synthesis in cells.[64] The transposition ofDs in different cells is random, it may move in some but not others, which causes color mosaicism. The size of the colored spot on the seed is determined by stage of the seed development during dissociation. McClintock also found that the transposition ofDs is determined by the number ofAc copies in the cell.[65]
Between 1948 and 1950, she developed a theory by which these mobile elements regulated the genes by inhibiting or modulating their action. She referred toDissociation andActivator as "controlling units"—later, as "controlling elements"—to distinguish them from genes. She hypothesized thatgene regulation could explain how complex multicellular organisms made of cells with identicalgenomes have cells of different function.[65] McClintock's discovery challenged the concept of the genome as a static set of instructions passed between generations.[3] In 1950, she reported her work onAc/Ds and her ideas about gene regulation in a paper entitled "The origin and behavior of mutable loci in maize" published in the journalProceedings of the National Academy of Sciences. In summer 1951, she reported her work on the origin and behavior of mutable loci in maize at the annual symposium at Cold Spring Harbor Laboratory, presenting a paper of the same name. The paper delved into the instability caused byDs andAc or justAc in four genes, along with the tendency of those genes to unpredictably revert to the wild phenotype. She also identified "families" of transposons, which did not interact with one another.[3][66][61]
McClintock with one of her results
Her work on controlling elements and gene regulation was conceptually difficult and was not immediately understood or accepted by her contemporaries; she described the reception of her research as "puzzlement, even hostility".[67][61] Nevertheless, McClintock continued to develop her ideas on controlling elements. She published a paper inGenetics in 1953, where she presented all her statistical data, and undertook lecture tours to universities throughout the 1950s to speak about her work.[68] She continued to investigate the problem and identified a new element that she calledSuppressor-mutator (Spm), which, although similar toAc/Ds, acts in a more complex manner. LikeAc/Ds, some versions could transpose on their own and some could not; unlikeAc/Ds, when present, it fully suppressed the expression of mutant genes when they normally would not be entirely suppressed.[69] Based on the reactions of other scientists to her work, McClintock felt she risked alienating the scientific mainstream, and from 1953 was forced to stop publishing accounts of her research on controlling elements.[3][59]
In 1957, McClintock received funding from theNational Academy of Sciences to start research on indigenous strains of maize in Central America and South America. She was interested in studying theevolution of maize through chromosomal changes,[70] and being in South America would allow her to work on a larger scale. McClintock explored the chromosomal, morphological, and evolutionary characteristics of variousraces of maize.[71][40] After extensive work in the 1960s and 1970s, McClintock and her collaborators published the seminal studyThe Chromosomal Constitution of Races of Maize, leaving their mark onpaleobotany,ethnobotany, andevolutionary biology.[72] See Kass (2024, Chapter 9), for extensive details of McClintock's research and influence on the cytogenetics of the Races of Maize in Mexico and South America.
McClintock officially retired from her position at the Carnegie Institution in 1967,[3] and was made a Distinguished Service Member of the Carnegie Institution of Washington.[52] This honor allowed her to continue working with graduate students and colleagues in the Cold Spring Harbor Laboratory asscientist emerita; she lived in the town.[73] In reference to her decision 20 years earlier to stop publishing detailed accounts of her work on controlling elements, she wrote in 1973:
Over the years I have found that it is difficult if not impossible to bring to consciousness of another person the nature of his tacit assumptions when, by some special experiences, I have been made aware of them. This became painfully evident to me in my attempts during the 1950s to convince geneticists that the action of genes had to be and was controlled. It is now equally painful to recognize the fixity of assumptions that many persons hold on the nature of controlling elements in maize and the manners of their operation. One must await the right time for conceptual change.[74]
The importance of McClintock's contributions was revealed in the 1960s, when the work of French geneticistsFrançois Jacob andJacques Monod described the genetic regulation of thelac operon, a concept she had demonstrated withAc/Ds in 1951. Following Jacob and Monod's 1961Journal of Molecular Biology paper "Genetic regulatory mechanisms in the synthesis of proteins", McClintock wrote an article forAmerican Naturalist comparing thelac operon and her work on controlling elements in maize.[75][69] Even late in the twentieth century, McClintock's contribution to biology was still not widely acknowledged as amounting to the discovery of genetic regulation.[59] See Kass (2024, pp. 189–191) for clarification of this legend.
McClintock was widely credited with discovering transposition after other researchers finally discovered the process in bacteria, yeast, andbacteriophages in the late 1960s and early 1970s.[76] During this period, molecular biology had developed significant new technology, and scientists were able to show the molecular basis for transposition.[77] In the 1970s,Ac andDs werecloned by other scientists and were shown to beclass II transposons.Ac is a complete transposon that can produce a functionaltransposase, which is required for the element to move within the genome.Ds has a mutation in its transposase gene, which means that it cannot move without another source of transposase. Thus, as McClintock observed,Ds cannot move in the absence ofAc.[78]Spm has also been characterized as a transposon. Subsequent research has shown that transposons typically do not move unless the cell is placed under stress, such as by irradiation or the breakage-fusion-bridge cycle, and thus their activation during stress can serve as a source of genetic variation for evolution.[79] McClintock understood the role of transposons in evolution and genome change well before other researchers grasped the concept. Nowadays,Ac/Ds is used as a tool in plant biology to generate mutant plants used for the characterization of gene function.[80]
Most notably, she received theNobel Prize for Physiology or Medicine in 1983, the first woman to win that prize unshared,[73] and the first American woman to win any unshared Nobel Prize in the sciences.[87] It was given to her by theNobel Foundation for discovering "mobile genetic elements";[88] this was more than 30 years after she initially described the phenomenon of controlling elements. She was compared toGregor Mendel in terms of her scientific career by theSwedish Academy of Sciences when she was awarded the Prize.[89] Nobel Prize awards and their limitations, and the rationale for delayed awards are detailed in Kass (2024, pp. 236–247).
McClintock giving her Nobel Lecture
She was elected aForeign Member of the Royal Society (ForMemRS) in 1989.[90] McClintock received theBenjamin Franklin Medal for Distinguished Achievement in the Sciences of theAmerican Philosophical Society in 1993.[91] She had been previously elected to the APS in 1946.[92] She was awarded 14 Honorary Doctor of Science degrees and an Honorary Doctor of Humane Letters.[40] In 1986 she was inducted into theNational Women's Hall of Fame. During her final years, McClintock led a more public life, especially afterEvelyn Fox Keller's 1983 biography of her,A Feeling for the Organism, brought McClintock's story to the public. She remained a regular presence in the Cold Spring Harbor community, and gave talks on mobile genetic elements and the history of genetics research for the benefit of junior scientists. An anthology of her 43 publicationsThe Discovery and Characterization of Transposable Elements: The Collected Papers of Barbara McClintock was published in 1987.[85]
McClintock spent her later years, post Nobel Prize, as a key leader and researcher in the field at Cold Spring Harbor Laboratory on Long Island, New York. McClintock died of natural causes inHuntington, New York, on September 2, 1992, at the age of 90; she never married or had children.[73][85][96]
McClintock was the subject of a 1983 biography by physicistEvelyn Fox Keller, titledA Feeling for the Organism. Keller argued that because McClintock felt like an outsider within her field, (in part, because of her sex) she was able to look at her scientific subjects from a perspective different from the dominant one, leading to several important insights.[97] Keller shows how this led many of her colleagues to reject her ideas and undermine her abilities for many years. For example, when McClintock presented her findings that the genetics of maize did not conform to Mendelian distributions, geneticistSewall Wright expressed the belief that she did not understand the underlying mathematics of her work, a belief he had also expressed towards other women at the time.[98] In addition, geneticistLotte Auerbach recounted thatJoshua Lederberg returned from a visit to McClintock's lab with the remark: 'By God, that woman is either crazy or a genius.' " As Auerbach recounts, McClintock had thrown Lederberg and his colleagues out after half an hour 'because of their arrogance. She was intolerant of arrogance ... She felt she had crossed a desert alone and no one had followed her.'"[99][100]
In 2001, a second biography, science historianNathaniel C. Comfort'sThe Tangled Field: Barbara McClintock's Search for the Patterns of Genetic Control challenged this narrative. Comfort's biography contests the claim that McClintock was marginalized by other scientists, which he calls the "McClintock Myth" and argues was perpetuated both by McClintock herself as well as in the earlier biography by Keller. Comfort, however, asserts that McClintock was not discriminated against because of her gender, citing that she was well regarded by her professional peers, even in the early years of her career.[101]
In 2024,From Chromosomes to Mobile Genetic Elements: The Life and Work of Nobel Laureate Barbara McClintock, a biography by Lee B. Kass, was released.[102]
Many recent biographical works on women in science feature accounts of McClintock's work and experience. She is held up as a role model for girls in such works of children's literature as Edith Hope Fine'sBarbara McClintock, Nobel Prize Geneticist, Deborah Heiligman'sBarbara McClintock: Alone in Her Field and Mary Kittredge'sBarbara McClintock. A recent biography for young adults by Naomi Pasachoff,Barbara McClintock, Genius of Genetics, provides a new perspective, based on the current literature.[103]
On May 4, 2005, theUnited States Postal Service issued the "American Scientists" commemorative postage stamp series, a set of four 37-cent self-adhesive stamps in several configurations. The scientists depicted were Barbara McClintock,John von Neumann,Josiah Willard Gibbs, andRichard Feynman. McClintock was also featured in a 1989 four-stamp issue from Sweden which illustrated the work of eight Nobel Prize-winning geneticists. A laboratory building at Cold Spring Harbor Laboratory was named for her. A street has been named after her in the new "Adlershof Development Society" science park inBerlin.[104]
Some of McClintock's personality and scientific achievements were referred to inJeffrey Eugenides's 2011 novelThe Marriage Plot, which tells the story of ayeast geneticist named Leonard who hasbipolar disorder. He works at a laboratory loosely based on Cold Spring Harbor. The character reminiscent of McClintock is a reclusive geneticist at the fictional laboratory, who makes the same discoveries as her factual counterpart.[107]
Judith Pratt wrote a play about McClintock, called MAIZE, which was read at Artemesia Theatre in Chicago in 2015, and was produced in Ithaca NY, the home of Cornell University, in February–March 2018.[108]
McClintock’s life continue to inspire novels and essays that reinterpret her life through imaginative storytelling, reflecting her enduring influence on both science and culture.[109] That includesRachel Pastan’s novel,In the Field (2021), which the author describes as an imaginative re-creation of the scientist’s solitude, dedication, and unconventional career.[110]
McClintock, B. (1945). "Neurospora. I. Preliminary Observations of the Chromosomes of Neurospora crassa".American Journal of Botany.32 (10):671–678.doi:10.2307/2437624.JSTOR2437624.
McClintock, B.; Kato Yamakake, T.A.; Blumenschein, A. (1981).Chromosome constitution of races of maize: Its significance in the interpretation of relationships between races and varieties in the Americas. Chapingo, Mexico: Escuela de Nacional de Agricultura, Colegio de Postgraduados.OCLC9181898.
^Keller, Evelyn Fox (1993) [1983].A feeling for the organism: the life and work of Barbara McClintock (10th anniversary ed.). New York: W.H. Freeman.ISBN0-8050-7458-9.OCLC29715247.
Kass, Lee B.; Bonneuil, Christophe (2004), "Mapping and seeing: Barbara McClintock and the linking of genetics and cytology in maize genetics, 1928–1935", inRheinberger, Hans-Jörg; Gaudilliere, Jean-Paul (eds.),Classical Genetic Research and its Legacy: The Mapping Cultures of 20th Century Genetics, London: Routledge, pp. 91–118
Kass, Lee B. (2024).From Chromosomes to Mobile Genetic Elements: The Life and Work of Nobel Laureate Barbara McClintock (1 ed.). CRC Press.ISBN9781032365350.
Comfort, Nathaniel C. (1999), ""The real point is control": The reception of Barbara McClintock's controlling elements",Journal of the History of Biology,32 (1):133–162,doi:10.1023/A:1004468625863,PMID11623812,S2CID2918489
Jin, W.Z.; Duan, R.J.; Zhang, F.; Chen, S.Y.; Wu, Y.R.; Wu, P. (November 2003), "Application of Ac/Ds transposon system to generate marker gene free transgenic plants in rice",Chinese Journal of Biotechnology,19 (6):668–673,PMID15971577
Kass, Lee B.; Provine, William Ball (1997), "Genetics in the roaring 20s: The influence of Cornell's professors and curriculum on Barbara McClintock's development as a cytogeneticist",American Journal of Botany,84 (6, Supplement): 123
Kass, Lee B. (2000), "Barbara McClintock: Botanist, cytologist, geneticist. Symposium Botany in the Age of Mendel, Abstract #193",American Journal of Botany,87 (6): 64,JSTOR2656784
Kass, Lee B. (2005b), "Missouri compromise: tenure or freedom. New evidence clarifies why Barbara McClintock left Academe",Maize Genetics Cooperation Newsletter (79):52–71
Keirns, Carla (Spring 1999), "Seeing Patterns: Models, Visual Evidence and Pictorial Communication in the Work of Barbara McClintock",Journal of the History of Biology,32 (1), Springer:163–196,doi:10.1023/A:1004420726771,JSTOR4331512,S2CID83266829
Klug, William S.; Cummings, Michael R.; Spencer, Charlotte A.; Palladino, Michael A. (2012),Concepts of Genetics (10th ed.), Boston: Pearson,ISBN978-0-321-72412-0
McClintock, Barbara (1934), "The relation of a particular chromosomal element to the development of the nucleoli in Zea mays",Zeitschrift für Zellforschung und Mikroskopische Anatomie,21 (2):294–328,doi:10.1007/BF00374060,S2CID24921807
McClintock, Barbara (1945), "Neurospora: preliminary observations of the chromosomes ofNeurospora crassa",American Journal of Botany,32 (10):671–78,doi:10.2307/2437624,JSTOR2437624
McClintock, Barbara (1987), Moore, John A. (ed.),The discovery and characterization of transposable elements: the collected papers of Barbara McClintock, New York: Garland Pub.,ISBN978-0-8240-1391-2
"1970 National Medal of Science",The Laureates, National Science and Technology Medals Foundation, 2009, archived fromthe original on September 11, 2012, retrievedDecember 28, 2012
Selvarajah S, Yoshimoto M, Park PC, Maire G, Paderova J, Bayani J, Lim G, Al-Romaih K, Squire JA, Zielenska M (December 2006), "The breakage-fusion-bridge (BFB) cycle as a mechanism for generating genetic heterogeneity in osteosarcoma",Chromosoma, 6,115 (6):459–467,doi:10.1007/s00412-006-0074-4,PMID16897100,S2CID12403557
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