Headline July 24, 2018/ " ' ANCIENT -DNA- VIRUSES ' "


IN JULY - SCIENTISTS REPORTED that a strange protein courses through the veins of pregnant women. No one is sure what it's there for.

What makes this protein, called Hemo, so unusual is that it's not made by the mother. Instead, it is made in her fetus and in the placenta, by a gene that- originally came from virus that infected our mammalian ancestors more than 800 million years ago.

Hemo is not the only protein with such an alien origin : Our DNA contains roughly 100,000 pieces of viral DNA .

Altogether they make up about 8 percent of the human genome. And scientists are only starting to figure out what this viral DNA is doing to us.

Aris Katzourakis, a virologist at the University of Oxford, and his colleagues recently published a commentary in the journal Trends in Microbiology in which they explored the produce proteins like  Hemo are affecting our health in a variety of unexpected ways.

Some of our ancient viruses may be protecting us from disease, others may be raising our risks for cancer, among other conditions.

"It's a lot more complicated than that," Dr. Katzourakis said in an interview. "We are barely at the beginning of this research."

Most of our viral DNA comes from group in particular : retroviruses, a group that includes H.I.V. A retrovirus invades a host cell and inserts its genes into that cell's DNA. These viral genes co-opt the cells machinery, using it to make new viruses that escape to infect more cells.

If a retrovirus  happens to infect an egg or sperm, its DNA can potentially be passed to the next generation and the generation after that. Once retroviruses become inherited stowaways, scientists refer to them as endogenous retroviruses.

At first, endogenous retroviruses coax cells to make more retroviruses that can infect other cells. But over the generations, the viral DNA mutates, and endogenous retroviruses eventually lose the ability to infect new cells.

Even after being hobbled, these endogenous retroviruses can still sometimes make their proteins. And they can also reproduce, after a fashion. They can force cells to make copies of their DNA, which are inserted back into the cell's own genome.

After a single infection, an endogenous retrovirus may build up hundreds of copies of itself in its host's DNA.

Some endogenous retroviruses are unique to humans, but others are found in a variety of species.

In January, Dr. Katzourakis was a co-author on a study showing that one retrovirus common in mammals also is present in fish like cod and tuna. Retroviruses, that study indicated were invading our marine ancestors 450 million years ago - or even earlier.

Just as we have defenses against free-living viruses, we have also developed defenses against endogenous retroviruses. Our cells can coat their DNA, with molecules that suppress viral genes, fir example.

But sometimes these viral genes manage to switch on anyway. In many kinds of tumour cells, for instance, scientist find proteins produced by endogenous retroviruses.

That discovery has fueled a long-running debate : Do endogenous retroviruses help cause cancer?

Recent studies suggest they can. A team of French researchers engineered healthy human cells to make a viral protein found in many tumors and watched the cells grow in a petri dish.

The Honor and Serving of the latest Global Operational Research Ancient and Newborn Viruses continues. The World Students Society - for every subject in the world - thanks author and researcher Carl Zimmer.

With respectful dedication to the Research Scientists, Medical Students, Dr. Najeeb Khan, and then the Students, Professors and Teachers of the world. See Ya all "register" on ..... wssciw. blogspot. com and Twitter !E-WOW! - the Ecosystem 2011:

"' Students Of  Research "'

Good Night and God Bless

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