By Melissa Healy, Los Angeles Times For the Booster Shots Blog
9:00 AM EDT, September 27, 2012 For decades after a woman has
carried a male child in her womb or shared her mother's womb
with a brother, she carries a faint but unmistakable echo of
that intimate bond: male fetal DNA that lodges itself in the far
recesses of her brain. That astonishing finding, published
Wednesday in the journal Public Library of Science One (PLoS
One), suggests that the act of having a child is no mere one-way
transmission of genetic material and all that goes with it:
There is an exchange of DNA that passes into the part of us that
makes us who we are. That, in turn, may alter a woman's health
prospects in ways her own DNA never intended. In the study,
researchers from the Fred Hutchinson Cancer Research Center and
the University of Washington examined, post-mortem, the brains
of 59 women. In 63% of the brains, they found fetal DNA that
could only have come from a male. While scattered throughout the
brain, the genetic traces