Madeleine Simonne Charnier
(15 June 1919—9 July 2002)
was a French
zoologist
Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the Animal, animal kingdom, including the anatomy, structure, embryology, evolution, Biological clas ...
. She is known for having first described
temperature-dependent sex determination Temperature-dependent sex determination (TSD) is a type of environmental sex determination in which the temperatures experienced during embryonic/larval development determine the sex of the offspring. It is only observed in reptiles and teleost fish ...
in 1966.
Biography
Charnier's mother was a mathematics professor.
Charnier received her license in science around 1935 at the Faculty of Sciences in Paris.
She moved to Africa around 1945
to join her brother: first to
Kaolack, Senegal, then to
Cotonou, Dahomey (now
Benin
Benin ( , ; french: Bénin , ff, Benen), officially the Republic of Benin (french: République du Bénin), and formerly Dahomey, is a country in West Africa. It is bordered by Togo to the west, Nigeria to the east, Burkina Faso to the north ...
), then to
Dakar, Senegal
Dakar ( ; ; wo, Ndakaaru) (from :wo:daqaar, daqaar ''tamarind''), is the capital city, capital and List of cities in Senegal, largest city of Senegal. The city of Dakar proper has a population of 1,030,594, whereas the population of the Dakar ...
at the end of the 1940s.
In 1953, she divorced her husband, Marcel Robert.
That year, she was hired at the university library of
University of Dakar
Cheikh Anta Diop University (french: Université Cheikh Anta Diop or UCAD), also known as the Cheikh Anta Diop University of Dakar, is a university in Dakar, Senegal. It is named after the Senegalese physicist, historian and anthropologist Cheikh ...
.
From 1955, Charnier worked at the faculty of medicine in
parasitology
Parasitology is the study of parasites, their hosts, and the relationship between them. As a biological discipline, the scope of parasitology is not determined by the organism or environment in question but by their way of life. This means it fo ...
, and received certificates in
coprology and
hematology
Hematology ( always spelled haematology in British English) is the branch of medicine concerned with the study of the cause, prognosis, treatment, and prevention of diseases related to blood. It involves treating diseases that affect the produc ...
.
There, she published her first scientific article on the
common agama
The common agama, red-headed rock agama or rainbow agama (''Agama agama'') is a species of lizard from the family Agamidae found in most of sub-Saharan Africa. To clear up historical confusion based on Linnaeus and other authors, Wagner, et al. ( ...
, which would become her preferred species to research for the next ten years (Charnier and Dutarte 1956).
In 1958, she left the faculty of medicine for the Faculty of Sciences at the University of Dakar. She completed her training in science to join the zoology department of Professor C. Boisson, a specialist in ciliated and opaline
protozoa
Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histo ...
. Charnier also met Claudine and Xavier Mattéi, who were researching the
morphology
Morphology, from the Greek and meaning "study of shape", may refer to:
Disciplines
* Morphology (archaeology), study of the shapes or forms of artifacts
* Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies ...
of
spermatozoa
A spermatozoon (; also spelled spermatozoön; ; ) is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote. (A zygote is a single cell, with a complete set of chromosomes, ...
. She was appointed
assistant professor
Assistant Professor is an academic rank just below the rank of an associate professor used in universities or colleges, mainly in the United States and Canada.
Overview
This position is generally taken after earning a doctoral degree and general ...
.
It was during this period that she published five articles on the
embryonic development
An embryo is an initial stage of development of 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 sperm ...
of the common agama (Charnier 1963;1965;1966b;a;1967), including her article temperature-dependent sex determination on this species in 1966.
Charnier observed that eggs incubated at a cool temperature produced female hatchlings, while those incubated at a warm temperature produced males, and posited that the sex of the hatchlings was influenced by the temperature.
This discovery was not widely recognized internationally for several years as it was published in French. It has now been referenced more than 230 times, making it one of the most cited zoology articles from the 1960s.
Charnier left Senegal in 1968
and abandoned her work on the agama, which was the subject of her
thesis
A thesis ( : theses), or dissertation (abbreviated diss.), is a document submitted in support of candidature for an academic degree or professional qualification presenting the author's research and findings.International Standard ISO 7144: ...
which she did not
defend. Once in France, she worked with Professor Jean Cachon in
Villefranche-sur-Mer
Villefranche-sur-Mer (, ; oc, Vilafranca de Mar ; it, Villafranca Marittima ) is a resort town in the Alpes-Maritimes department in the Provence-Alpes-Côte d'Azur region on the French Riviera and is located south-west of the Principality of ...
. Charnier published another scientific article on the
ultrastructural
Ultrastructure (or ultra-structure) is the architecture of cells and biomaterials that is visible at higher magnifications than found on a standard optical light microscope. This traditionally meant the resolution and magnification range of a co ...
morphology of a
siphonophorean parasite (Cachon et al. 1972).
Charnier retired in 1984 in
Nice
Nice ( , ; Niçard: , classical norm, or , nonstandard, ; it, Nizza ; lij, Nissa; grc, Νίκαια; la, Nicaea) is the prefecture of the Alpes-Maritimes department in France. The Nice agglomeration extends far beyond the administrative c ...
and died in 2002 at the age of 83.
Legacy
Charnier's work on temperature-dependent sex determination opened the door investigating the role of
estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal acti ...
in determining sex and the implications of
global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
on reptiles,
as well as to a large number of works on this subject which have implications in the fields of
developmental biology
Developmental biology is the study of the process by which animals and plants grow and develop. Developmental biology also encompasses the biology of Regeneration (biology), regeneration, asexual reproduction, metamorphosis, and the growth and di ...
,
evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...
, and
ecology
Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...
.
Bibliography
*Cachon, J., M. Cachon, and M. Charnier. 1972. Ultrastructure du bodonidé ''Trypanophis grobbeni'' Poche, parasite des siphonophores. Protistologica 8:223-236.
*Charnier, M. 1963. Action de l'hormone mâle (hexahydrobenzoate de testostérone) sur les femelles dAgama agama'', Saurien. Agamidae. Comptes Rendus des Séances de la Société de Biologie, Paris 157:1470-1472.
*Charnier, M. 1965. Le cycle sexuel chez le lézard male ''Agama agama'' (Reptilia, Lacertilien) dans la région de Dakar. Annales de la Faculté des Sciences de Dakar 18:33-59.
*Charnier, M. 1966a. Action d'une hormone femelle sur le tractus genital des mâles adultes du lézard ''Agama agama'' (Lacertilian, Agamidae). Comptes Rendus des Séances de la Société de Biologie 159:1822-1825.
*Charnier, M. 1966b. Action de la température sur la sex-ratio chez l'embryon dAgama agama'' (Agamidae, Lacertilien). Comptes Rendus des Séances de la Société de Biologie, Paris 160:620-622
scanned version of the article*Charnier, M. 1967. Le développement embryonnaire de l'appareil genital du lézard ''Agama agama''. Annales de la Faculté des Sciences, Université de Dakar 20:23-32.
*Charnier, M., and J. P. Dutarte. 1956. Changement histophysiologique de la thyroïde des lézards de la région de Dakar durant la période préhibernatoire. Comptes Rendus des Séances de la Société de Biologie, Paris 150:1387-1388.
References
Madeleine Charnier's daughter Annie Brun provided some of the information here.
{{DEFAULTSORT:Charnier, Madeleine
1919 births
2002 deaths
Scientists from Lille
20th-century French women scientists