Male DNA --> Female Brain

     A recent discovery suggests that fetal cells can slip through the blood-brain barrier and into the female brain. Scientists have traced segments of male DNA, considered to be from ‘boy fetuses’, embedded in brain tissue of women who have died in their 70’s. Male DNA is also very common throughout the female brain. An online report (PLOS ONE), electronically published on September 26, clarifies the discovery. Researcher, J. Lee Nelson of the Fred Hutchinson Cancer Research Center in Seattle, studied 26 female brains and 18 out of the 26 male-only genes (69%) died without neurological disease. With that said, male DNA was profusely present throughout their brains. In relation to this particular study, the technique used couldn’t determine whether the DNA originated from ‘intact, functional brain cells’. Nelson and the cancer center researchers conducted a similar test, a different sample of female brain tissue and sited nuclei from male cells in the brain. Geneticist Kirby Johnson of Tufts University in Medford, Mass conservatively noted that, “from everything we knew, it’s not really that surprising. What’s interesting is how the DNA could have gotten there. Male cells from a fetus could have broken through the blood-brain barrier — a wall that protects the fragile brain from pathogens in the blood. But that shouldn’t be possible” (Johnson). Mothers can also carry a daughter’s genetic material in their brain tissue and with the presence of a Y chromosome it makes male DNA easier to locate.  

* Information obtained at www.sciencenews.org

* Pictures obtained at www.frenchtribune.com & news.yahoo.com 

 Figure 9.1 

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