The Mosaic of DNA, and the Woman who Can Rearrange It

March 6, 2019 8:07 AM

You may have your mom's smile, but do you also have your older brother's DNA? Tim Flannery reviews Carl Zimmer's She Has Her Mother's Laugh, with fascinating insights into heredity, chimerism, and mosaicism. In January, the NYR also interviewed Jennifer Doudna, who discovered CRISPR and grapples with its implications.
posted by Hypatia (9 comments total)

To anyone who thinks we have heritability figured out...
posted by Mental Wimp at 8:49 AM on March 6, 2019 [1 favorite]

"Imagine if gene editing can be used to treat wasting muscles, or Alzheimer’s, or to prevent HIV infection (as was allegedly done to a pair of unborn twins recently in China)—how long would it be before those same techniques are used to create super-muscles or super-cognition?"

I know these speculations are always tempered by warnings of doom and horror, but I can't help but be excited about this. Seems like a good next step in technology, if the survival of humanity beyond the next centuries or even the planet is a goal, seems like genetic engineering will be a must. Realistically climate change is going to create an environmental inhospitable to the average person, and we obviously aren't going to do anything about it now or the foreseeable future. However, when it gets to that point, perhaps we will be able to just modify humans to the new environmental conditions.
posted by GoblinHoney at 9:22 AM on March 6, 2019 [1 favorite]

There are a bunch of amazing things in that article. For example:

Chimeras can also result from pregnancy. Cells from embryos regularly cross via the placenta into the mother during gestation, while her cells can end up in the embryo. It is astonishing how long such cells can survive. One woman who had given birth to a son still had cells with Y-chromosomes in her body twenty-seven years later. In another case, an entire lobe of a woman’s liver that had been damaged by disease was repaired by fetal cells that remained in her body after an abortion. A mother’s brain cells, too, can be derived from offspring.

If you are a pregnant woman with some kind of physiological problem, your developing fetus may try to fix it for you.
posted by jamjam at 10:37 AM on March 6, 2019 [7 favorites]

One of my friends had heart failure from pregnancy, and she recovered entirely, which apparently is partly because fetal cells in the bloodstream will end up in the heart and repair it.
posted by tavella at 10:42 AM on March 6, 2019 [6 favorites]

The implications of this for our current concept of identity are pretty amazing!
posted by heatherlogan at 10:51 AM on March 6, 2019 [3 favorites]

The book is great. I bought it after seeing good twitter buzz and seeing the endorsement by Ed Yong, (who also has the best TED talk I've ever seen about parasites). I put off starting it because it's a bit of a tome at over 500 pages, but it's a shockingly quick and engaging read. Really really worth cracking open.
posted by pykrete jungle at 5:56 PM on March 6, 2019

Well, I won't be alive at the point the ruling families who own the gene-editing labs turn their own kind into superhumans who will kill or enslave the rest of the population forever. So maybe that's something. (Sorry for the doom and horror.)
posted by Glinn at 6:41 PM on March 6, 2019

analysis of the sample revealed that the cells of Fairchild’s body were derived from two genetically distinct female eggs that had fused to form one individual. Her sex cells came from one egg, while the parts of her body used in the DNA test came from the other.

Mind blown.

Great article thanks for posting.
posted by St. Peepsburg at 8:57 PM on March 6, 2019 [1 favorite]

I've been trying to figure out how to get tested for chimerism for AGES. Ever since I was very little I have been absolutely certain that I was meant to be a twin, even though my family all swear that there was only ever one of me. When I first found out about this in 2004 I was all "OMG WHAT YES" but I've never really shown any reason to get tested. I don't have any obvious chimeric symptoms (like different patches of hair colour or different eye colours, though that's not really going to be super variable if you're brown) and no real reason to check (asides from this feeling deep down in my bones that would explain a lot about my life), so I don't know how to even begin to get this tested. Wragh.
posted by divabat at 2:03 AM on March 7, 2019