Étude historique de la visualisation de l’acide désoxyribonucléique

Abstract

The history of the visualization of deoxyribonucleic acid (DNA): mythical molecule is at the crossroads of the chemical, genetic and cytological sciences. In the 19th century, Miescher discovered an amorphous chemical substance phosphated in cell nuclei, while Mendel described the «invisible factors» of heredity and Flemming identified «chromatin» under the microscope. In 1952 Franklin discovers the X-ray diffraction spectrum of the DNA molecule that inspires Watson and Crick’s antiparallel complementary-strand double-helix model, a molecular support for heredity with its self-replicating potential. Between 1970 and 2 000 the code of DNA is decrypted leading biologists, computer scientists and robots to sequence the human genome in 2 000 and murine in 2002, while affirming the winding of the molecule into nucleosomes. The challenge of the post-genomic era is the visualization of the genome in 3 dimensions, given that 98% of the human genome does not code for proteins. Starting in the 2000s, the «chromosomal conformation capture» approach offers a «topological» view of the genome at an intermediate level between the molecular and the cytological. Multi-scale modeling (atomic, intermediate or «coarse grains», polymers) corroborated by experimental techniques allows the research to be structured in a global network around the project «nucleoma 4D» an «augmented» vision of genomic DNA to better understand the disease base and to design new therapeutic paradigms.