Molecular biology goes back to the discovery in 1953 by Watson and Crick of the double helix DNA molecule. Since that time, numerous achievements have been accomplished. Molecular biology offers tremendous opportunities through genetic engineering. Applications include plants, animals and potentially human beings. These developments are highly controversial, especially in Europe, but commercial applications are already widespread and presently 77% of soybean produced in the world is genetically modified. Applications include also genetically modified micro-organisms (algae, bacteria, mushrooms) for producing pharmaceuticals and fine chemicals. More disturbing is the capacity of producing "synthetic" viruses. In 2002, the biologist Eckard Wimmer and his team were able to synthetize the poliomyelitis virus. According to Eckard Wimmer, it is now possible to synthetize dreadful virus such as the polyovirus or the hepatisis virus for a few cents and the Ebola virus for a few dollars. It is even possible to reproduce a virus, which has completely disappeared, just by knowong the genetic sequence. Thus, publishing the formula of such a sequence is a way to ensure the survival of the virus. It has been possible to reproduce the virus of Spanish influenza eight decades after it apparently disappeared, by deciphering the genome sequence of the virus from specimens of tissues which were held at low temperature. The danger of such manipulations is quite obvious as the dreadful viruses might be released by accident or intentionnally as weapons. It is even possible to imagine the potential synthesis of genetically modified viruses with new properties, which would make impossible their prevention.
La biologie a franchi une étape décisive avec l’élucidation des mécanismes moléculaires de synthèse des protéines. La découverte de la molécule en double hélice de l’ADN par Watson et Crick est déjà ancienne, puisqu’elle remonte à 1953. On a pu alors montrer que les molécules d’ADN portent toute l’information génétique, sous forme d’une séquence de gènes. Chaque gène est une unité d’information génétique représentée par une certaine configuration de bases chimiques. Depuis la découverte de la structure de la molécule d’ADN, la biologie moléculaire a réalisé des progrès spectaculaires, avec notamment la mise au point de méthodes de séquençage permettant d’identifier l’ensemble des gènes. En l’an 2000, était annoncé le décryptage complet du génome humain, réalisé simultanément par un consortium international et par la compagnie Celera, créée par le biologiste et homme d’affaires Craig Venter.
