What's the Difference Between Female DNA and Male DNA?
The "female" DNA sequence is incomplete because it lack DNA from the Y chromosome.
We Now Know that female contains XX chromosomes and male contains XY chromosomes which determines their gender. But a shocking news is that some women may harbor a male chromosomes.
The blood of women who have given birth to boys often contains Y-chromosome gene sequences. This is thought to happen during pregnancy. But even women who don't have sons sometimes have the "male" DNA.
Authors of a study on the subject speculate that possible sources of the DNA could be an unrecognized male pregnancy or unknown male twin, or sexual intercourse alone.
The study, is the first description of male microchimerism in the female human brain. Microchimerism is when someone harbors cells that came from a genetically distinct individual.
The serious side of this is that scientists working at the Fred Hutchinson Cancer Research Center have linked the phenomenon to autoimmune diseases and cancer, sometimes for better and other times for worse.
The scientists believe it is likely that fetal cells frequently cross the human blood-brain barrier and that microchimerism in the brain is relatively common. Until this study, it was not known whether these cells could cross the barrier in humans.
The
researchers examined brain autopsy specimens 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.
Twenty six of the women had no neurological disease and 33 had
Alzheimer’s disease. The brains of women with Alzheimer’s had a somewhat lower
prevalence of male microchimerism, which appeared in lower concentrations in
regions of the brain most affected by the disease. However, the authors noted
that the small number of subjects and largely unknown pregnancy history of the
women means a link between Alzheimer’s disease and level of male cells of fetal
origin cannot be established
Currently, the biological significance of harboring male DNA and male cells in the human brain requires further investigation.
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