Experimental Evidence of 2,3,7,8-Tetrachlordibenzo-p-Dioxin (TCDD) Transgenerational Effects on Reproductive Health.

Previous studies have demonstrated that endocrine disruptors (EDs) can promote the transgenerational inheritance of disease susceptibility. Among the many existing EDs, 2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD) affects reproductive health, including in humans, following direct occupational exposure or environmental disasters, for instance the Agent Orange sprayed during the Vietnam War. Conversely, few studies have focused on TCDD multigenerational and transgenerational effects on human reproductive health, despite the high amount of evidence in animal models of such effects on male and female reproductive health that mimic human reproductive system disorders.

Protistology and Cell Biology at the Marine Arago Laboratory of Banyuls-sur-Mer (1961-2000): Personal Recollections.

The history of protistology and the introduction of modern methods of unicell observations is described in a large maritime laboratory over a period of forty years by the initiator of this new team. The development of this team and the doctoral theses developed there are described as well as the major discoveries made. The Arago Laboratory, which was then in 1960 a field laboratory mainly devoted to the collection of biological material, becomes a research laboratory specializing in the study of the major fundamental problems which govern life: the organization and expression of the genome, mitotic processes and their nuclear and cytoplasmic components, cell cycle and its regulation as well as molecular phylogeny.

The Arago Laboratory of Banyuls and some of its Academicians.

Since its founding in 1881 by Henri de Lacaze-Duthiers (1821-1901), the Arago Laboratory of Banyuls has been one of the three marine stations of the University Pierre and Marie Curie-Paris 6. It is located in Banyuls (Banyuls-sur-Mer) in Northern Catalonia. The center hosts researchers and students from all over the world.

Chromosomes of Protists: The crucible of evolution.

As early as 1925, the great protozoologist Edouard Chatton classified microorganisms into two categories, the prokaryotic and the eukaryotic microbes, based on light microscopical observation of their nuclear organization. Now, by means of transmission electron microscopy, we know that prokaryotic microbes are characterized by the absence of nuclear envelope surrounding the bacterial chromosome, which is more or less condensed and whose chromatin is deprived of histone proteins but presents specific basic proteins. Eukaryotic microbes, the protists, have nuclei surrounded by a nuclear envelope and have chromosomes more or less condensed, with chromatin-containing histone proteins organized into nucleosomes.

Association between fetal DES-exposure and psychiatric disorders in adolescence/adulthood: evidence from a French cohort of 1002 prenatally exposed children.

In utero diethylstilbestrol (DES) exposure has been demonstrated to be associated with somatic abnormalities in adult men and women. Conversely, the data are contradictory regarding the association with psychological or psychiatric disorders during adolescence and adulthood. This work was designed to determine whether prenatal exposure to DES affects brain development and whether it is associated with psychiatric disorders in male and female adolescents and young adults.

Prevalence of hypospadias in grandsons of women exposed to diethylstilbestrol during pregnancy: a multigenerational national cohort study.

Prenatal diethylstilbestrol (DES)-exposed mice have raised the suspicion of a transgenerational effect in the occurrence of genital malformation in males. This nationwide cohort study in collaboration with a French association of DES-exposed women studied 529 families and showed that a significant proportion of boys born to DES daughters exhibited hypospadias with no other molecular defects identified.

Methods for studying the nuclei and chromosomes of dinoflagellates.

Dinoflagellates are unicellular eukaryotic organisms whose nuclear structure, chromosome architecture, chromatin organization, DNA composition, and mitosis show original features. It has been necessary to adapt techniques and to create innovative methods for growing cells, isolating nuclei, and studies of their chromosomes by transmission electron microscope (TEM). Among these are innovative squash and whole-mount preparations for light and TEM observations of chromosome architecture and the spatial organization of nucleofilaments.

Molecular characterization of iron-containing superoxide dismutases in the heterotrophic dinoflagellate Crypthecodinium cohnii.

Superoxide dismutases (SODs) are a family of antioxidant enzymes that catalyse the degradation of toxic superoxide radicals in obligate and facultative aerobic organisms. Here, we report the presence of a multi-copy gene family encoding SODs in the heterotrophic dinoflagellate Crypthecodinium cohnii. All the genes identified (sod1 to sod17) have been cloned and sequenced, and shown to encode potentially functional dimeric iron-containing SOD isozymes.

Edouard Chatton (1883-1947) and the dinoflagellate protists: concepts and models.

Edouard Chatton contributed to our knowledge of single-celled protoctists, especially ciliates and dinoflagellates, free-living and/or symbiotic, in relation to the marine invertebrate animals in which they reside. More than the description of many new families, genera and species, and of their life cycles, he anticipated several major concepts of cell biology, including the fundamental difference between prokaryote and eukaryote protists, long time before the advent of electron microscopy. These concepts included: the reproductive ability of the kinetosome-centriole system; the homology of the kinetosome with the mitotic centriole of animal cells; and the different kinds of mitotic systems.

Evolution of plant-like crystalline storage polysaccharide in the protozoan parasite Toxoplasma gondii argues for a red alga ancestry.

Single-celled apicomplexan parasites are known to cause major diseases in humans and animals including malaria, toxoplasmosis, and coccidiosis. The presence of apicoplasts with the remnant of a plastid-like DNA argues that these parasites evolved from photosynthetic ancestors possibly related to the dinoflagellates. Toxoplasma gondii displays amylopectin-like polymers within the cytoplasm of the dormant brain cysts.

Permanent expression of a cyclin B homologue in the cell cycle of the dinoflagellate Karenia brevis.

The eukaryotic cell cycle is driven by a set of cyclin-dependent kinases associated with their regulatory partners, the cyclins, which confer activity, substrate specificities and proper localization of the kinase activity. We describe the cell cycle of Karenia brevis and provide evidence for the presence of a cyclin B homologue in this dinoflagellate using two antibodies with different specificities. This cyclin B homologue has an unusual behavior, since its expression is permanent and it has a cytoplasmic location throughout the cell cycle.

Scientific research at the Laboratoire Arago (Banyuls, France) in the twentieth century: Edouard Chatton, the "master", and André Lwoff, the "pupil".

Edouard Chatton (1883-1947) began his scientific career in the Pasteur Institute, where he made several important discoveries regarding pathogenic protists (trypanosomids, Plasmodium, toxoplasms, Leishmania). In 1908 he married a "Banyulencque", Marie Herre; from 1920, he focused his research on marine protists. He finished his career as Professor at the Sorbonne (Paris) and director of the Laboratoire Arago in Banyuls-sur-mer, where he died in 1947.