Until now, scientists believed that only retroviruses could plant their genetic code in the hosts, but normal viruses do not have this ability * The assessment - evolution preserved the genes because they protected the hosts from infection
In a study published on July 29 in the journal PLoS Pathogen, researchers discovered that the genome of vertebrates, including humans, contains ancient sequences of a virus from the Ebola/Marburgviruses family and of Bornaviruses - two families of deadly viruses.
Because no other virus family injects its genetic material into the host's genome the way retroviruses do, the discovery was unexpected.
"It was a surprise for us," says Anna-Maria Skalka, retired director of the Cancer Research Institute at the Fox-Chase Center. "This means that the origin of our genetic material is much more diverse than we thought. It includes our own genes as well as the unexpected genes of viruses.
The team, led by Prof. Vladimir Bailey and partnered by Dr. Arnold Levin, both from the Institute for Advanced Study in Princeton, compared 5,666 viral genes from all known families of non-retroviruses, single-stranded RNA viruses, with the genomes of 48 vertebrates, including humans.
In doing so, they uncovered 80 distinct genome sequences, and interestingly, almost all of the virus sequences came from ancient relatives of two virus families. Ebola - Marburgviruses and Bornaviruses, both cause hemorrhagic fever and neurological diseases.
"These viruses are based on RNA," says Skalka. According to her, they replicate their own RNA and do not know how to produce DNA at all. "They have no known mechanism that can insert their genetic material into the host's DNA. Some of them don't even know how to enter the nucleus when they replicate."
These sequences, some of which may have been integrated into the genome for more than 40 million years, have been largely conserved during evolution, indicating that they give their host a selective advantage. Perhaps by preventing future infection by viruses from these families. The study showed that the integration of the ancient virus sequences was apparently mediated by moving elements LINEs, which are common in the genome of mammals. "In a way you can even think of it as a combination of a genetic vaccine" said Skalka.
Further work will be required to understand whether these viral sequences have biological significance. However, the team notes that expression of some of the viral reading frames has been detected in human tissues, supporting the possibility that these sequences are biologically active in the host organisms.
to the notice of the researchers
http://www.sciencedaily.com/releases/2010/07/100729172330.htm
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Very interesting. It is likely that this is the result of a double infection with both a normal RNA virus and a retrovirus.
Hey, are you a troll again?
This really does not undermine Darwin's theory. To remind you, Darwin did not know what genes were and what genetics was, although Mendel discovered these laws around the same time, but his writings were not published in a normal and accessible place for the scientific community until the beginning of the twentieth century.
As a matter of fact, Darwin referred to the fact that each generation is slightly different from the previous one but still contains most of the characteristics, and that is also the case in this case. Note that even the researcher talks in terms of evolution about a survival advantage,
What's more, it undermines the scarecrow of evolution of Amnon Yitzchak and his friends who think that evolution mixes in every generation and is therefore random to Halvetin, but as mentioned, it's just a scarecrow that makes him fall and he falls, not the real evolution.
Itzik,
The accepted statistical measure of genetic similarity is E-value.
You can read about it and the accepted methods of determining genetic similarity (Blast fasta and others) here:
http://www.ncbi.nlm.nih.gov/BLAST/tutorial/Altschul-1.html
Basically the index determines what is the chance, assuming everything is random, that two sequences will show the similarity found between them. The lower the value, the higher the likelihood that they are indeed similar. The similarity is not random and they have a common origin.
In DNA, values smaller than 0.001 are considered good similarity.
In proteins, since we are talking about 20 amino acids, even much higher values will be considered similarity.
What length of gene sequence is considered a transplant? Maybe such sequences were created by chance here and here? What statistically cannot be the same by chance?
As far as I know in music only over 7 notes is considered plagiarism.
I once thought about the subject and really came to the conclusion that only retroviruses have "motivation" and the ability to insert themselves into the genome.
I explained the reasons I came to in this response:
https://www.hayadan.org.il/the-resurrection-of-a-disease-linked-gene-1103096/#comment-187927
At the time - when I read about the subject, I saw that there are exceptions to the matter and there is another family of viruses called adeno associated that also know how to integrate into the genome.
http://en.wikipedia.org/wiki/Adeno-associated_virus
Regarding the current story - I can assume that the introduction of the DNA segments of the viruses happened due to a parallel infection of the person - both with the retro virus and with the virus in question.
The retro virus created a reverse transcriptase that also served the RNA virus that happened to be there at the time.
Radioactive radiation (cellular and/or cosmic and/or fission).
Does it cause a change in the genome coils and the release / creation of viruses in addition
Refresh, the answer to your question is here: http://he.wikipedia.org/wiki/%D7%9E%D7%97%D7%A1%D7%95%D7%9D_%D7%95%D7%99%D7%99%D7%A1%D7%9E%D7%9F
In the last section: recent findings on the principle
How did these viruses manage to pass the Weismann barrier?
How did these viruses manage to pass the Weissman barrier?
Avi Vigael they can even be harmful and it is not certain that you can get rid of them. As far as I know, cells do not know how to selectively remove DNA fragments of retroviruses from their genomes, and neither can scientists (at least at the moment, I know of an Israeli freelance scientist who is developing a molecule that is supposed to remove copies of retroviruses from the genome in cooperation with the pharmaceutical company soup).
Father, they do not have to be beneficial, it is enough that they are not harmful to the point of destroying their host, and even that only to the extent that allows it to produce offspring. That is, it is enough that the host (which is no longer a host because these genes are part of its genome) reaches sexual maturity without them harming it to the extent that it prevents the birth of offspring, for them to be passed on to future generations. There is no need for utility for their survival. The genome is full of "junk genes" some of which may or may not be useful.
And it can also explain where these viruses come from, and disappear without leaving a trace of their hosts.
It is enough that the segment of the virus in the vertebrates is broken for some reason, and the virus is free to infect.
Viruses in a genetic coma that can act even after tens of millions of years.
Very interesting, thanks
The article shows that evolution has many methods of passing genes, apart from the well-known approach and the vertical transfer of genes, i.e. from generation to generation.
Lateral transfer of genes is a familiar thing, especially in the world of bacteria and archaea. The fact is that they randomly arrived in the sand dunes but stayed there (and this is a non-random element of evolution) because they gave some advantage to a creature infected by them.