What: A deep dive from the Atlantic looking at “cell microchimerism”, where embryos deposit bits of genetic material wherever they implant. One example? A woman with Y chromosomes in her thyroid, likely from a male embryo the patient had once carried.
Why it matters: Scientists are split. Some argue that the cells are “so sparse and inconsistent [they] couldn’t possibly have meaningful effects.” Others “contend that microchimeric cells aren’t just passive passengers, adrift in someone else’s genomic sea.”
Source: The Atlantic