By Bernie Bell
I was reading this article, which I found to be of great interest, and thought that maybe Neil Shubin’s information about viruses – how we, as a species, deal with them, and have dealt with them in the past – even the very distant past – might be of interest to Orkney News readers.
I hope that copyright allows me to quote extensively from this article, as I am just about to do so!
“The legacy of ancient viruses
Shubin described another example of repurposing, one that involves an evolutionary surprise revealed by recent work in genetics: Ancient viruses, after invading the bodies of our distant ancestors, got incorporated into the human genome. “Almost 10 percent of our genome is a graveyard for ancient viral infections,” he said.
One early virus appears to have been repurposed by the human genome and harnessed for different ends, Shubin explained, describing the discovery of neurobiologist Jason Shepherd, who studies the genetic and physiological basis of memory.
Shepherd’s work focused on a gene called Arc, which is involved in memory. Mice who have a mutation in Arc can solve a maze but can’t remember their solution the next day. Humans who have a mutation in the gene experience a range of cognitive deficits.
As he examined the proteins made by Arc with a microscope, Shepherd realized their appearance was identical to an image he’d seen before: human immunodeficiency virus (HIV), the virus that causes AIDS. As it turns out, the sequence and structure of Arc and its proteins contain the classic signature of a virus similar to HIV, said Shubin. Just as the protein clumps on HIV help move genetic material from cell to cell, Arc acts in a similar way, but for a different function.
Shepherd and his colleagues hypothesize that sometime in the distant past — several hundred million years ago — a virus invaded the DNA of one of our distant ancestors. “Instead of causing an infection, it was domesticated, and it was repurposed for a new use,” said Shubin.”
We are a complex species – with a biology which appears to be endlessly adaptable, and adapting.
And, as Mr Shubin says – we are all part of one whole