Over ten years ago I read an article about fetal cells crossing the placenta into the mother’s body proper and remaining there for decades. Male DNA in a mother may be how this was discovered. I told a friend who suffered a loss that a part of her daughter is still with her.
Previously, I imagined a womb to be like a hammock with a feeding tube. The article made me envision some fetal cells shedding and Mommy’s body putting them in a keepsake box.
A few days ago an NY Times article describing a strange protein coursing through the veins of pregnant women, changed my perception. This protein called Hemo is not made by the mother but by her fetus and placenta, via a gene that originated from a virus infecting our mammalian ancestors over a 100 million years ago. Scientists don’t know its purpose if any. I’m reminded of the Sci-Fi series, Extant with Halle Berry, but I exaggerate. Nevertheless, a poorly understood exchange is going on between mother and fetus.
I did not expect a virus to be involved. A virus is defined as a microorganism that can only replicate by usurping a living cell. According to that definition it doesn’t necessarily cause disease. Part of the communication from fetus to mother may be to prevent her immune system from harming the fetus, to keep that food coming, and to prep the mammary glands. Maybe it’s related to those strange pregnancy cravings?
Fetal cells are like stem cells. They can transform into a variety of different cells (heart, lung, whatever), depending on what they are told to be by molecular signals, another process that is not well understood. When they drift into the mother’s body, they may be assimilated into the surrounding tissue. If not, they are sluffed off after birth.
8% of the human genome consists of viruses. Aris Katzourakis, a virologist at the University of Oxford, conjectures these ancient viruses may play a positive or negative role, but feel they have an effect on human health. Virologists also conjecture that studying them may help in understanding cancer. A retrovirus takes over a cell and replicates much as a cancer cell does.
I met a woman over the weekend who became allergic to chocolate after her second pregnancy. Hmm?
I hope we’ll find the purpose of what’s going on some day. I find all of this most bizarre.