Nobody wants to viruses, most of all it is not clear if they are alive or not. My first reaction when I saw (in pictures) at t4 virus is that it was an animal. Has some sort of ducklings, which are folded to that through a tube of proteins injected into the host DNA. So to have some movement. The capsule (head) has a strange diamond-shaped, very geometrical that associate with life, and in fact these viruses can be crystallized, which does not associate with life.
The Tree of Life project are three related domains, the Archaea, which are like bacteria, many of which are found in places where the devil himself would find hard to live, the eubacteria, or common bacteria and eukaryotes, which are the rest . And there in a faraway place, a mark which says only VIRUS (www.tolweb.org). as if it had nothing to do with the rest of the other living beings.
But viruses are a major part of the biomass of the oceans, that's a significant amount, think, more than all the fish, and algae, increiblemete something big, but almost study. If we are not affected, better not think about the virus and its rare and much less in its enormous diversity, much like the rest of the other three domains.
Patrick Forterre, began studying the E. coli and how she used the gut enzymes to replicate, without introducing DNA in them, that naturally led him to study the virus and also was amazed with the T4 is this live? Where did it come from?.
The orthodox theory of the origin of viruses is that they were fragments of DNA or RNA that escaped, for some reason in the genomes of other living beings. This, taken with variations was accepted by all y. or so everyone believed, and so the question mark in the page tree of life project on the word virus.
the late 80's and early 90 techniques in the study of the genome were not accurate enough to begin studies on these creatures. Carl Woese with these techniques showed that some bacteria, and bacteria were not created another domain the of Archean , deeper studies in which I participate Forterre realized using enzymes unique to the replication of DNA, different from bacteria and eukaryotes. Others began to look bacteriophage T4 enzyme that copies DNA differently (I will not go into technicalities, but believe me it is so).
That was not consistent with the theory that genetic material was missed, after all the viruses have no metabolism, if such genes should have escaped the same enzymes replicating their guests. Do not invent something new.
But replicating enzymes of T4 have no connection with the infecting bacteria. Something was
terribly wrong.
more similar examples were found, of enzymes that had no counterpart in the cells. That led to Patrick Forterre for explosive lecture in 1985 which suggested that viruses were part of another domain, before the other three and so were old, very old, and perhaps were the first life on earth.
That has now been established that genes encoding proteins in the shells of the virus, also found in the other three domains, this
suggests that an ancestor of virus infected the members of the other three domains, and it gets more and more new evidence that they are the remnant of another domain, now extinct.
was proposed that DNA replication had developed twice, once in protovirus and again in the rest of living things, such are the differences, things were becoming more confused and more crazy assumptions were taken seriously.
And even to this day the picture is unclear, there are many hypotheses.
But let's give it another turn of the screw.
There is considerable consensus that DNA-based organization from others that were based on RNA, the RNA could not only carry encoded information, if not also serve as an enzyme.
This could be the dominant form of life makes some 3700 million years. These agencies could absorb nutrient medium and also to evolve, whether those agencies could create their own proteins into the virus early.
Even now, there are many viruses that reproduce by HIV RNA chains and the flu are examples.
But DNA is more stable than RNA and less prone to mutate. That is an issue that many theorists have found, but DNA reproduction in the body provides long term benefits, not short-term advantages.
And that's the way evolution works, seeking benefits for the individual, not their progeny.
Forterre offered an alternative to this dilemma.
For DNA viruses could provide a huge immediate advantage, could offer protection against attacks of RNA viruses.
The current cells have a wide range of attacks against viruses based on RNA, can silence, with RNA molecules themselves (as with HIV) or can cut it into smaller pieces.
RNA viruses try to avoid it and therefore alter their genes to thwart the host.
Thus, using this mechanism, the first virus could alter the structure of an effective, twisted chains to form a double helix. (After all only differ in one nucleotide) and thus better able to thwart the attackers and thus found a way to survive within a host for generations as the cells to reproduce too would make them.
are domesticated, they lost some some genes they used to escape and to make layers of protein and become naked DNA.
Over time some RNA viruses attached to them and enjoy the benefits that have previously made. Were more stable. Natural selection favored the body had DNA. And the decreased RNA and DNA grew.
That takes fragments of RNA might happen three times, and thus form the domains. This explains the differences and overlap.
could be that the infected protovirus eukaryotes and Archie and why they are so similar mechanisms. Eukaryotes
For example, DNA remain stuck within the core, to protect it. The poxviruses, can form shells similar to the core within their hosts. Yet
cells of eukaryotes are complex and strange, maybe this is just part of the story.
In this way the virus could make up the DNA and all of us are extremely virus exist and only exist for them.
But still little is known about the virus. Only well known to cause disease or bacteria that attack the economic effects. But now studying the virus are living with the Archaea, which have proven to be very different and strange, some of them only when they are completely out of the guest.
is incredible that the virus research tell us more that we are and what the hell do in this world.
The next years will be very interesting in this field.
science
Venezuela
science virus, virus ,
Comments (4 items)
Author: equinoXio Created: Thursday, March 29, 2007 16:41:00
Hi Luis:
Very interesting this synthesis of the virus. I am one who thinks that they are not living things, however, although this is a decision more or less randomly. However, a cell organnelo such as mitochondria (which also have their own DNA) are not considered organisms, but part of the machinery of an organism. As these organelles as active and essential for life, you might consider a separate organism living in symbiosis within a larger one, then, as the criteria for life are met with far more extensively than in the case of the virus. According
, unmitigated, data on biomass and structural diversity in this huge family of viruses warrants further study and consideration in the theories of the evolution of life, because regardless of whether or not living things, have significantly altered the evolution of species.
Finally, there are interesting applications to achieve some cures to diseases genetic, in which the use of viruses (especially RNA retrovirus) is a must.
A special greeting from Bogota, THILO.
