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Lucien Claude Marie Julien Cuénot (; 21 October 1866 – 7 January 1951) was a French biologist. In the first half of the 20th century, Mendelism was not a popular subject among French biologists. Cuénot defied popular opinion and shirked the “pseudo-sciences” as he called them. Upon the rediscovery of Mendel's work by Correns, De Vries, and Tschermak, Cuénot proved that Mendelism applied to animals as well as plants.


Cuénot's experiments

Cuénot spent two years working on mice and came to the conclusion that three “mnemons” (genes) are responsible for the production of one “chromogen” or
pigment A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...
and two “distases”
enzymes An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as pro ...
. The pigment (if present) is acted upon by the enzymes to produce black or yellow colour. If no pigment is present the result is an
albino Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and reddish pink or blue eyes. Individuals with the condition are referred to as albinos. Varied use and interpretation of ...
mouse. Cuénot studied the offspring of various crosses between mice and concluded that these “mnemons” or
genes 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 ...
were inherited in a Mendelian fashion. Subsequently, Cuénot was the first person to describe multiple allelism at a genetic locus. He also described a lethal
mutation In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, ...
in the mouse agouti locus at a time when such a mutation was unheard of.


Recognition

There is some argument over the degree of recognition of Cuénot's pioneering work in his own day, and up until the present. Some scientists who were famous in Cuénot's day such as
William Bateson William Bateson (8 August 1861 – 8 February 1926) was an English biologist who was the first person to use the term genetics to describe the study of heredity, and the chief populariser of the ideas of Gregor Mendel following their rediscover ...
, the man credited the "one gene one enzyme" hypothesis never recognized Cuénot's discovery that certain traits arose due to the presence or absence of an enzyme. Bateson did receive a letter from Charles Chamberlain Hurst in which he was urged to "read and digest the new Cuénot", work which explained some results in the field of mouse genetics, results which had been confusing for Bateson. Other scientists who were well known in Cuénot's own day and still into the present day, such as Clarence Little and
Sewall Wright Sewall Green Wright ForMemRS HonFRSE (December 21, 1889March 3, 1988) was an American geneticist known for his influential work on evolutionary theory and also for his work on path analysis. He was a founder of population genetics alongside ...
, and William E. Castle did credit Cuénot with pioneering work in genetics. For example, Clarence Little and William E. Castle did credit Cuénot with the discovery of the first lethal mutation. The mouse geneticist Clarence Little credited Cuénot with the idea and first evidence for multiple allelism, and recognizing that the inheritance of white spotting in the mouse did not breed true. The mouse and population geneticist
Sewall Wright Sewall Green Wright ForMemRS HonFRSE (December 21, 1889March 3, 1988) was an American geneticist known for his influential work on evolutionary theory and also for his work on path analysis. He was a founder of population genetics alongside ...
credited Cuénot with the discovery of multiple alleles and the one-gene one-enzyme hypothesis. When writing Cuénot's obituary in 1951, Richard Goldschmidt credits Cuénot with the gene controlling enzyme hypothesis: John Cairns as recently as 2003 credited Lucien Cuénot with the one-gene one-enzyme hypothesis. The entry on "
Albino Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and reddish pink or blue eyes. Individuals with the condition are referred to as albinos. Varied use and interpretation of ...
" in the ''Encyclopædia Britannica'' (11th, 1911) does fully appreciate Cuénot's work on the relationship between determinants (genes) and ferments (enzymes): Cuénot's studies on mice were cut short when German troops invaded the town of Nancy, where he kept his mouse colony. After the
First World War World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...
he never returned to his studies on mice and moved on to designing a theory of evolution, halfway between ''en vogue'' French
Lamarckism Lamarckism, also known as Lamarckian inheritance or neo-Lamarckism, is the notion that an organism can pass on to its offspring physical characteristics that the parent organism acquired through use or disuse during its lifetime. It is also calle ...
and Darwinism.


Selected publications

*''L'Adaptation'' (1925) *''Le Transformisme'' ith Élie Gagnebin, Louis Marius Vialleton">Louis_Marius_Vialleton.html" ;"title="ith Élie Gagnebin, Louis Marius Vialleton">ith Élie Gagnebin, Louis Marius Vialleton(1927) *''La Genèse des espèces animals'' (1932) *''Variation et mutation en bactériologie'' (1932)


References


Further reading

*Denis Buican, "Mendelism in France and the Work of Lucien Cuénot", ''Scientia'', 1982, LXXVI, 117, 1-4, 129-137. * {{DEFAULTSORT:Cuenot, Lucien 1866 births 1951 deaths French geneticists Scientists from Paris