Monday, November 21, 2011
Not a one-way street!
Now this is interesting!
Note the emphasized sentence in last paragraph, showing that this is not just a research-mouse phenomenon.
Note also the automatic Richard Dawkins selfish-gene assumption in "the fetus promotes its own survival". That's not even a proper Darwinian assumption; Darwin would use the hypothesis that each species does what it can to keep its own line going.
Or you could interpret it without any assumptions: Lord, what a marvelous arrangement. Pregnancy can be hard on the mother, so let's compensate. Allow the baby to rebuild his mother while the baby is at his most "creative" stage.
And some kids continue the job later on! ¶ 4:49 AM
Why wait to be born to develop a healing hand? Mouse fetuses will give up stem cells to repair their mother's heart. The discovery could explain why half the women who develop heart weakness during or just after pregnancy recover spontaneously.
Hina Chaudhry of the Mount Sinai School of Medicine in New York City mated normal female mice with males genetically engineered to produce a green-fluorescing protein in all their body cells. Half the resulting fetuses also produced the protein, making it easy to spot any fetal tissue in the mother.
Chaudhry's team inflicted a heart attack on the pregnant mice and killed them two weeks later to take a look at their hearts. They found some fluorescent cells in the mothers' damaged heart tissue, where they had accelerated repair by changing into new heart cells, including beating cardiomyocytes and blood vessel cells.
Chaudhry says that the phenomenon is an evolutionary mechanism: the fetus promotes its own survival by protecting its mother's heart. Because the cells are easy to obtain from the placenta and unlikely to cause immunological reactions, they could provide a new and potentially limitless source of stem cells for repairing damaged hearts.
Previous research has identified fetal stem cells in other damaged organs of pregnant women, including the brain, liver, kidney and lung. Fetuses also produce cells that are known to protect the mother against breast cancer.
Note the emphasized sentence in last paragraph, showing that this is not just a research-mouse phenomenon.
Note also the automatic Richard Dawkins selfish-gene assumption in "the fetus promotes its own survival". That's not even a proper Darwinian assumption; Darwin would use the hypothesis that each species does what it can to keep its own line going.
Or you could interpret it without any assumptions: Lord, what a marvelous arrangement. Pregnancy can be hard on the mother, so let's compensate. Allow the baby to rebuild his mother while the baby is at his most "creative" stage.
And some kids continue the job later on! ¶ 4:49 AM
