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Mastermind or freeloader? Viral proteins in early human embryos leave researchers puzzled

and_virus_makes_four_fullI'm filing this finding firmly under the category of "Things I'm glad I didn't know when I was pregnant." (Other items include the abject terror of letting your teen get behind the steering wheel of a car for the first time, and the jaw-dropping number of zeros that can appear in a college financial aid package.) Recently, Stanford researchers found that the earliest stages of human development - those that occur within days of fertilization - may take place in a stew of viral proteins that lie in wait tucked inside the human genome. What do the viral proteins do? Who knows! Why are they popping up when we're (arguably) at our most vulnerable? No idea!

Ugh. Like there's not enough to worry about while growing another human inside your body.

I'm not being entirely fair here. Developmental biologist Joanna Wysocka, PhD, and graduate student Edward Grow, were some of the first researchers to show that ancient viral DNA sequences abandoned in our genome after long-ago infections can and do make viral proteins early in human development. I wrote about their finding on this blog earlier this year.

My article in the most recent issue of Stanford Medicine magazine expands on this story, describing how they made their finding and their future plans to learn more about our viral co-pilots. As I explain:

The finding raises questions as to who, or what, is really pulling the strings during human embryogenesis. Grow and Wysocka have found that these viral proteins are well-placed to manipulate some of the earliest steps in our development by affecting gene expression and even possibly protecting the embryo’s cells from further viral infection.

I'm often struck by how much parenting is like research. It's a (seemingly) never-ending, but very rewarding, job. And for both, there's clearly always lots to learn. As I write:

So, who’s in charge here? Us or the viruses? Or is there no longer any distinction? There’s certainly been plenty of evidence showing that humans are far from free operators when it comes to, well, pretty much anything. Our bodies are teeming masses of bacteria, viruses and even fungi that are collectively known as the microbiome. Many of these microorganisms, which are 10 times more numerous than our own cells, are essential to a healthy life, such as the gut bacteria that help us digest our food.

“What we’re learning now is that our ‘junk DNA,’ including some viral genes, is recycled for development in the first few days and weeks of life,” says [study co-author and former Stanford stem cell researcher Renee Reijo-Pera], who is now on the faculty of Montana State University. “The question is, what is it doing there?”

Previously: Stanford Medicine magazine tells why a healthy childhood mattersMy baby, my...virus? Stanford researchers find viral proteins in human embryonic cells and Species-specific differences among placentas due to long-ago viral infection, say Stanford researchers
Photo of Joanna Wysocka by Misha Gravenor

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