A new study suggests that male DNA in female brains is generated during pregnancies and may affect the autoimmune system.
The male DNA is commonly exchanged between mother and fetus during pregnancies, according to Science Daily.
The study of a process called “microchimerism” involving male DNA in women’s’ brains is the first of its kind to identify male fetuses as the source of male DNA that is commonly found in the female brain, according to the current article from Science Daily.
The findings suggest the likelihood that fetal cells “frequently cross the human blood-brain barrier and that process, called microchimerism in the brain, is relatively common.”
The human stage of research included scientific examination of brain autopsy specimens taken from 59 women who had died between the ages of 32 and 101. Male microchimerism was “detected in 63 percent of subjects, was distributed in multiple brain regions and was potentially persistent throughout the human lifespan; the oldest female in whom male fetal DNA was detected in the brain was 94.”
The Science Daily report said 26 of the women were free of neurological disease while 33 had Alzheimer's. The brains of women that that had Alzheimer's evidenced less male microchimerism in lower concentrations in regions of the brain more severely affected by Alzheimer's.
It is important to note that the authors report that the small number of subjects and sketchy pregnancy history of the female subjects does not establish a link between the level of male DNA derived from fetuses and less occurrence of Alzheimer's disease, but instead suggests there may be such a link but more studies are required to confirm.
PLOS ONE first published the study Sept. 26.
F. N. Chan, Ph.D., from the Department of Biochemistry at the University of Alberta, was the lead author. The research was conducted in the Hutchinson Center laboratory of J. Lee Nelson, M.D., a member of the Center's Clinical Research Division and a leading international authority on microchimerism and senior author on the paper.
The study also does not provide an association between male microchimerism in the female brain and relative health versus disease. "Currently, the biological significance of harboring male DNA and male cells in the human brain requires further investigation," Chan said.