Would you read a story about a new advance in in vitro fertilization, whereby an inherited mitochondrial disease is averted through transplantation of a fertilized nucleus?
How about a story about scientists creating the first embryo with three parents?
That’s what I thought. Never mind the scientists, who in one well-reported story, said “it would be incorrect to say that the embryos have three parents.”
What really happened was a neat but unfrightening transplant of a fertilized egg nucleus (with the standard set of DNA from two parents) into a donor egg containing a third woman’s mitochondria. As you may remember, mitochondria are those little steam engines that live in our cells by the thousands. They have their own set of DNA that governs how their machinery converts glucose into energy the rest of the cell can use.
Interestingly, mitochondria are the descendants of bacteria that our cells enveloped way back in the mists of evolutionary time back when “we” were some version of multicellular sludge in a tidepool somewhere. Mitochondrial DNA has had very little to do with the rest of our genes ever since – it’s one reason why they’re so useful to biologists tracing evolutionary lineages. So given the origin of mitochondria, you might just as well argue that we all have three parents.
But what good is explaining all that to a headline writer who has only 10 words with which to catch the eyes of thousands of readers? That’s how we get “Brit scientists brew up three-parent embryo” and similar rickety headlines appearing all over the world.
Fortunately, the world has someone who calls out headline abuses such as these: the Knight Science Journalism Tracker. It’s his job to scan news stories each day and point out what’s been done right and wrong. It’s much-needed peer review for journalists, conducted by one of their own with four decades (correct me if I’m wrong) of experience. Worth checking regularly.
And how did the Tracker resist the too-easy headline for his own post? He bypassed “parents” and went straight for the oldest attention grabber of them all: Sex triangle – though the headline continues, honorably: “An embryo with one woman’s mitochondria, and another’s nuclear DNA (a man’s involved too) “
(Image via the X-men)