You are conflating different types of chimerism. Also the paper you cited stated that the women with the highest microchimerism were women with induced abortions. Because a fetus chimerized the mother, not sperm. Its not proven that sperm itself chimerizes.
How do you know they were never pregnant? How do they know they were never pregnant? They dont.
How do you know whose Y chromosomes they are? Why couldnt they belong to the mother’s father? If sperm can burrow in to any tissue and replicate inspite of being haploid, why isn’t this daddy’s jizz?
“Male microchimerism in women without sons: quantitative assessment and correlation with pregnancy history” — cant find the full text of this.
“Male microchimerism in the female brain.”
The most likely source of male Mc in female brain is a woman’s acquisition of male DNA from pregnancy with a male fetus
One of two women without history of having sons was also positive for male Mc in her brain and without neurologic disease;
All I got from that study was that both microchimerism and also not having kids will protect a woman from alzheimer’s
(post is archived)