Viruses
Viruses are important pathogens of humans and animals. Their genomes are relatively small. For these reasons they were among the first organisms to be fully sequenced. The complete DNA sequence of the Epstein-Barr virus was completed in 1984. Bluetongue virus (BTV) has been in the forefront of molecular studies for last three decades and now represents one of the best understood viruses at the molecular and structural levels. Other viruses such as Papillomavirus, Coronavirus, Caliciviruses, Paramyxoviruses and Influenza virus have also been extensively studied at the molecular level.
Bacterial viruses, or bacteriophages, are estimated to be the most widely distributed and diverse entities in the biosphere. Bacteriophages, or "phage", have been fundamental in the development of the science of molecular biology and became "model organisms" for probing the basic chemistry of life. The first DNA-genome project to be completed was the phage Φ-X174 in 1977. Φ29 phage, a phage of Bacillus, is a paradigm for the study of several molecular mechanisms of general biological processes, including DNA replication and regulation of transcription.
Read more about this topic: Molecular Microbiology