Bataillon, Jean Eugène
Bataillon, Jean Eugène
(b. Annoire, Jura, France, 22 October 1864; d. Montpellier, France, 1 November 1953)
Bataillon was the son of a stone mason. Although he had a scholarship to the petit séminaire of Vaux-sur-Poligny, he refused to prepare for an ecclesiastic career. After he had passed the first part of his baccalauréat ès lettres in 1882, he became a surveillant at the Collège d’Arbois; after passing the second, he was made assistant master at the Belfort lycée and started work on his licence in philosophy. Bataillon next went to Lyons as master at the lycée and, when he had passed his baccalauréat ès sciences, he became a student under the physiologist Fernand Arloing. As a licencié ès sciences naturelles, he became an assistant in zoology at the University of Lyons in 1887 and learned the elementary techniques of experimental embryology under Laurent Chabry.
On 17 April 1891, Bataillon presented a thesis for the doctorate in science, La métamorphose des amphibiens anoures. Seconded by Pasteur, he was made acting lecturer at the Faculté des Sciences at Lyons and deputy lecturer in zoology and physiology at Dijon in 1892. There he became professor of general biology (the first chair so named in France) in 1903, and dean in 1907. It was in Dijon that he discovered the traumatic parthenogenesis of the batrachians. Appointed professor at the University of Strasbourg, which was being reorganized in 1919, he first set up a new laboratory and then temporarily served as rector. He became rector of the University of Clermont-Ferrand in 1921 but left this administrative position in 1924 to accept a professorship of zoology and comparative anatomy at Montpellier, There he met his principal collaborator, Chou Su, who thereafter helped him in his research. In 1932 Chou Su had to return to China to teach, and Bataillon decided to retire ahead of time. He went to live with one of his sons at Castelnau-le-Lez and later on the outskirts of Montpellier, where he died. He had become a corresponding member of the Académie des Sciences in 1916 and a full member in 1946. He was awarded the Osiris Prize of the Academy in 1951.
The experimental attempts to produce parthenogenesis with sodium chloride and sugar hypertonic solutions or butyric acid had failed, resulting only in an abortive segmentation of the egg (simple activation). During an experimental attempt to fertilize Bufo calamita with sperm of Triturus alpestris, Bataillon, struck by the resemblance of the spermatozoa to fine needles, thought of substituting glass or platinum stylets for them. On a Sunday in March 1910 the experiment performed on Rana temporaria was successful and resulted in 90 percent of the eggs being segmented, of which about 10 percent evolved into normal larvae able to survive.
The analysis of these results demonstrated that besides the simple pricking (first activating factor) there is a second regulating factor, which can be identified as a cell or an inoculated cellular fragment. Operating upon eggs freed of their gelatin coating by potassium cyanide, Bataillon demonstrated, in an elegant experiment, using horse blood that had been defibrinated and sedimented, that the element inoculated was a leukocyte. Later, J. Shaver revealed that the active element is a cytoplasmic fragment rich in ribonucleoproteins.
By this interpretation Bataillon corrected Guyer’s error. Guyer had attributed to the nucleus of the leukocyte, released inside the egg by the pricking, the power to divide itself and to direct the embryogenesis. The activator thus provoked the “proper reaction” of the egg membrane, making any further fertilization impossible; there followed a special monocentric rhythm, a succession of monopolar mitoses that were, of course, abortive. The second regulating factor was necessary to determine the sequence of the bipolar mitoses (dicentric or amphiastral rhythm), the only ones capable of bringing about segmentation and, consequently, normal development. An intermediate type of mitosis, bipolar but anastral, appeared when the regulation was insufficient.
Electric shocks, pricking by galvanocautery, and the action of fat solvents could all be the activating factor, but only a biological factor could be the regulator. The latter, however, was not a specific: blood of other anurans, urodeles, fish, or mammals could replace the blood of Rana. The action of potassium cyanide as a chemical unsheathing agent was a fortuitous discovery which confirmed that unfertilized eggs pricked, but not smeared with blood, never undergo morphogenesis; it also made possible the experiment with defibrinated and sedimented horse’s blood, which could be performed only on naked eggs. Eggs sheathed in serum before pricking showed no regular cleavage; those sheathed in red corpuscles showed only 1 percent; and those sheathed in leukocytes showed 75 percent. The extract of hepatopancreas from the Astacus was useful in distinguishing the nonactivated eggs, which were cytolyzed, from the activated ones; the latter, through strengthening of the activating membrane, were able to resist cytolysis. This membrane had to be “modified in thickness,” a concept confirmed by modern electronic microscopic research (the bursting of the cortical granules liberated their contents, which then reinforced the vitelline membrane).
Bataillon emphasized this paradox: the spermatozoa of Rana, when penetrating the eggs of Bufo, caused fewer normal developments than did the Rana blood inoculated in Bufo eggs. He gave the explanation that the inoculated leukocyte acts only as regulator and does not cause any intervention due to chromosome incompatibilities. G. Hertwig, causing irradiated spermatozoa of Rana to act upon eggs of Bufo, obtained the same results and came to absolutely the same conclusion. Traumatic parthenogenesis generally leads to haploid larvae, but occasionally diploids may result either from an ovule whose polar mitosis aborted or from a secondary regulation through the fusion of divided nuclei. In such cases a few diploid larvae undergo metamorphosis. The regulation factor therefore can substitute dicentric mitosis for monocentric mitosis but cannot double the number of chromosomes that remain haploid. The role of this factor was confirmed by research done with Chou Su on immature and overmature eggs, and subsequently on “false hybrids,” where incompatible nuclei act only as regulation factors.
Bataillon’s work, although extremely original, is little known, and his role as a precursor is underestimated. His own modesty and deliberate reticence have lessened his reputation. His unchallenged discovery of traumatic parthenogenesis is important, but even more important is his remarkable analysis of the process, which clarified the complex phenomena of fertilization.
I. Original Works. Among Bataillon’s writings are “L’embryogenèse complète provoquée chez les amphibiens par piqûre de l’oeuf vierge, larves parthénogénésiques de Rana fusca,” in Comptes rendus de l’Académie des sciences, 150 (1910), 996–998; “Les deux facteurs de la parthénogenèse traumatique chez les amphibiens,” ibid., 152 (1911), 920–922; and Une enquête de trente cinq ans sur la génération, J. Rostand, S.E.D.E.S., ed, (Paris, 1955), which sums up his work.
II. Secondary Literature. Writings on Bataillon include R. Courrier,” Notice sur la vie et les travaux d’Eugène Bataillon,” in Notices et discours de l’Académie des sciences, 3 (1954), 1–26, which sums up his work; M. F. Guyer, “The Development of Unfertilized Frog Eggs Injected With Blood,” in Science25 (1907), 910–911; G. Hertwig,” Parthenogenesis bei Wirbeltieren hervorgerufen durch artfremden radiumbestrahlten Samen,” in Archiv für mikroskopische Anatomie, 81 (1913), 87; and J. Shaver, “The Role of Cytoplasmic Granules in Artificial Parthenogenesis,” in Journal de cyto-embryologie belgonéerlandaise (1949), 61–66.