Why Do Cells From Your Extended Family
Settle Inside Your Organs
In
the 1990s, Diana Bianchi at Harvard University and her colleagues made a
peculiar discovery. They found that women who had given birth to boys up to 27
years earlier still had their sons’ cells circulating in their blood. “We were
very surprised - it really changed our thinking about pregnancy,” says Bianchi,
who is now director of the US National Institute of Child Health and Human Development
in Maryland.
Other
groups later found mothers’ cells in their children’s blood, even when the
children had become young adults. Together, these findings suggest that while
we are in utero, a small proportion of our cells cross into our mothers and
vice versa, then stick around for decades.
Put
this goes even further because it is thought that we also harbor cells from
older siblings, uncles, aunts and grandmothers. One study of 154 Danish girls,
aged 10 to 15, found that 14 percent of them had male cells circulating in
their blood. This was more likely to be the case if they had an older brother.
This could occur if a mother absorbed cells from her son while he was in utero,
then passed those cells on to her daughter during a subsequent pregnancy. In theory,
if the daughter later passed her brother’s cells onto child of her own, that
child would cany their uncle’s cells.
New
Scientist Weekly, January 24 – February 7, 2024; Mysterious You p. 33.
