Boris Ephrussi (Russian: Борис Самойлович Эфрусси; 9 May 1901 – 2 May 1979), Professor of Genetics at the University of Paris, was a Russo-French geneticist.

Boris Ephrussi
Born(1901-05-09)May 9, 1901
DiedMay 2, 1979(1979-05-02) (aged 77)
EducationSorbonne University
California Institute of Technology
AwardsRosenstiel Award (1972)
Scientific career
InstitutionsJohns Hopkins University
Institut de Biologie Physicochimique
Academic advisorsT.H. Morgan
Doctoral studentsPiotr Słonimski

Boris was born on 9 May 1901 into a Jewish family. His father, Samuel Osipovich Ephrussi, was a chemical engineer; his grandfather, Joseph Ephrusi (Efrusi), was the founder of a banking dynasty in Kishinev. He published two papers in November 1966 which represented a key step in a decade of research in his laboratory. This research helped transform mammalian, and especially human, genetics.[1][2]

Boris started his scientific training as a Russian émigré in 1920. He studied the initiation and regulation of embryological processes by intracellular and extracellular factors. A major strand of his early research concerned the effect of temperature on the development of fertilized sea urchin eggs. In this work he used a micromanipulator, which was developed by Robert Chambers, an American biologist.

During Ephrussi's time, writing a second dissertation was standard practice in France. Ephrussi's involved culturing tissues.[1] Ephrussi ran into difficulties typically associated with early tissue culture techniques, but despite these obstacles Ephrussi managed to conclude from studies of brachyury in mice that intrinsic factors (i.e. genes) play a key role in development.

As the next phase of his career, Ephrussi coupled his embryological concerns with a firm conviction that one must understand the role of genes in order to decipher embryological processes. He moved to Caltech in 1934 and stayed until 1935 to learn genetics within the intellectual empire of T.H. Morgan. This move was supported by the Rockefeller Foundation. During this period he conducted important work with George Beadle, who joined him in Paris in the autumn of 1935. There they produced results from experiments with Drosophila eye transplants.[3] This became integral to the work of Beadle and Tatum, who were working with Neurospora, and from this research developed the 'one gene, one enzyme' hypothesis. During World War II, Ephrussi spent most of his time as a refugee at Johns Hopkins University. Following this he began work in France on yeast and cytoplasmic genetics. He began working at the Institut de Biologie Physicochimique (the Rothschild Institute) in Paris, and later worked at the CNRS at Gif-sur-Yvette, where he studied the contribution of cytoplasm to the cell phenotype and pursued the interactions between nuclear and cytoplasmic genetic endowments necessary to the yielding of an intact, functioning (albeit single-celled) organism.[4] Boris Ephrussi was a pioneer in questioning the consensus at the time that heredity could be accounted for exclusively by nuclear genes.[5][6] Ephrussi famously said, "we cannot determine the truth of a hypothesis by counting the number of people who believe it."[7]

Ephrussi was elected to the American Academy of Arts and Sciences (1958),[8] the United States National Academy of Sciences (1961),[9] and the American Philosophical Society in 1970.[10]

Ephrussi continued to work on the topics he was primarily interested until the late 1970s. Topics covered included

  • using hybrids with teratomas to explore determination and differentiation (e.g. Finch and Ephrussi 1967; Kahan and Ephrussi 1970).
  • negative regulation of differentiated function (e.g. Davidson, Ephrussi and Yamamoto 1966; Fougbre, Ruiz and Ephrussi 1972).
    Harriet Taylor, Audre Luoff, Jacques Monod, Boris Ephrussi, MS-001 7 1 58 3 P 0033, Archives at NCBS
    From left to right- Harriet Taylor, Audre Luoff, Jacques Monod, Boris Ephrussi with an issue of the New Yorker at the Cold Spring Harbor Symposium.
  • cellular and genetic biological approaches over a direct attack at the molecular level (Ephrussi 1970, p. 12).

In 1974 Ephrussi won a Louisa Gross Horwitz Prize from Columbia University. Ephrussi lived to see that transplantation was transforming into a genetic tool that would take on a new and more powerful aspect in the molecular era. However he died before seeing the genetic advances made by DNA recombination studies which had been set in motion by the studies he had undertaken. It can be said that Ephrussi was a pioneer of embryology and a main contributor to the reconciliation of modern genetics and Embryology.

He was married to Harriett Ephrussi-Taylor (1918–1968), a geneticist. His daughter, Anne Ephrussi, is a geneticist at the European Molecular Biology Laboratory.

References

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  1. ^ Burian R. 1990. Boris Ephrussi and the Foundations of Developmental Genetics. In Gilbert S. (ed) Developmental Biology, New York, Plenum.
  2. ^ Sapp J. 1987. Beyond the gene: cytoplasmic inheritance and the struggle for authority in genetics. New York, Oxford University Press.
  3. ^ Ephrussi B. 1939. Génétique physiologique. Paris, Hermann.
  4. ^ Ephrussi B. 1953. Nucleo-cytoplasmic relations in micro-organisms: their bearing on cell heredity and differentiation. Oxford.
  5. ^ Lindegren, Carl C. (1967). The Cold War in Biology. Planarian Press.
  6. ^ Livingston, Laura R. (1968). "Review: The Cold War in Biology". Yale Journal of Biology and Medicine. 41 (3): 290. PMC 2591340.
  7. ^ Ephrussi B. 1953. Nucleo-cytoplasmic relations in micro-organisms: their bearing on cell heredity and differentiation. Oxford. page vi. Ephrussi took the words from Joseph Henry Woodger (Symp. Soc. Expl. Biol 2: 354 (1948)) who wrote, "Admittedly, some hypotheses have become so well established that no one doubts them. But this does not mean that they are known to be true. We cannot determine the truth of a hypothesis by counting the number of people who believe it, and a hypothesis does not cease to be a hypothesis when a lot of people believe it."
  8. ^ "Boris Ephrussi". American Academy of Arts & Sciences. Retrieved 9 September 2022.
  9. ^ "Boris Ephrussi". www.nasonline.org. Retrieved 9 September 2022.
  10. ^ "Boris Ephrussi". www.nasonline.org. Retrieved 9 September 2022.

^ see Ephrussi 1935a

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