VIROSFERA EMERGING VIRUSES OR ALIENS?
Viruses are the most numerous inhabitants of planet earth. They also assumed a different and far more extensive than once thought (Bernard Dixon, ed. Microb., ASM, 2007)
The hundreds of millions of deaths from smallpox, influenza and yellow fever have been reduced by new acquisition model of how the virus life on Earth and influence the events of
'man. A critical review of the 'ecology of these viruses leads to important conclusions (January Meeting of the Soc for Microbiol. Edinburgh, Scotland, 2007).
Virus animals, humans, plants, bacteriophages are true forms of life and represent the most abundant biological entities on earth.
viruses define the composition and behavior of bacterial populations. They play a very important role in the biochemical cycle in terrestrial and horizontal gene transfer.
(Patrick Forterre, Institute Pasteur, Paris).
viruses known (the tip of the 'iceberg) have a greater diversity of genomic material for cells and mechanisms of genomic replication.
There are no genes identical for all viruses. The majority of metagenomic sequences are not similar to those found in existing databases.
Sea, marine sediment, soil, faeces: metagenomic sequences present in 'environment are the major reservoir of material of unknown sequences (Mya Breitbart' s University of Florida, St. Petersburg).
viral communities are extremely diverse with more than 10,000 viral genotypes contained in 1 kg of marine sediment, and then hundreds of thousands of viral genotypes in the oceans of the world.
L 'bacteriological activity helps define the regular season of' epidemic cholera (Faruque Shah, Int Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh). The peak of
'is preceded by the epidemic prevalence in the' environment of Vibrio cholerae, followed by high ambient levels of phage in which the bacterium is sensitive and then later following the collapse of the 'epidemic. Similarly, prophages
influence virulence, the 'evolution and diversity of bacterial pathogens. The
Citrobacter rodentium has six prophages that contain genes presumably involved in
inserted into the genome of 'destroy host functions such as motility of the bacterium (Nicola Petty et al., University of Cambridge, England).
Marine sediments are one of the largest ecosystems on the planet (Mathias Middelboe, University of Copenhagen, Denmark).
viruses affect marine microbial mortality, diversity and the biochemical cycle of the Earth.
1 cm ³ of surface marine sediment contains from 108 (one hundred million) in 1010 (10 billion) of virus, 10-100 times more than the overlying water column. From 12 hours to 5 days is the time required for the virus by up to 40% the production of bacteria deep. Thus viruses are important components of the biosphere integrated marina.
Cyanobacteria are key members of the population of phytoplankton and the sea of \u200b\u200bspring water. Cyanophages and lateral gene transfer regulates the structure and 'development of cyanobacterial populations. Cianofogi infect as many as 35 different genes in cyanobacteria (Li Deng and Paul Hayes, Bristol University, UK).
Viruses can play a significant role in carbon cycling in systems dominated microbes such as lakes of 'Antarctica (Johanna Laybourn-Parry, University of Keele, UK and University of Lund, Sweden).
Nature and origin of the virus.
Discovery of unusual virus in prokaryotes and eukaryotes variety giants with the recent progress in comparative genomics and structural biology has brought back the current issue of the nature and the 'origin of the virus.
current cellular genomes and mechanisms of DNA replication could be a strain of those originating in the primordial virosfera of DNA viruses infecting the cells with RNA.
If this hypothesis is confirmed, the virus may have played a key role in the transition from the old cell genomes RNA to DNA genomes of modern cells, and then in 'have established the first cellular molecule of life (Forterre Patrick). In conclusion
viruses as agents of death and disease go to the inventors of DNA
