Wasn't The Dark Half by Stephen King a similar thing?
No it's different to that (that novel is ace BTW!).
Chimerism is where two or more separate blastocysts merge and form one individual with cells of two or more DNA profiles - way before any foetuses have developed.
The Dark Half was about a parasitic twin - where one blastocyst that was splitting to create identical twins doesn't progress correctly, usually resulting in extra body parts on the dominant twin.
I was prompted to start reading up on this by some lovely poster (can't recall who sadly) suggesting chimerism when I pondered whether it would be possible for two conjoined twins to develop perfectly symmetrically, with the appearance of one individual.
That would of course be different to a chimera, but I'm fascinated by this whole subject
The fact that one fertilized egg can absorb another in the womb. Your own twin hiding within your very cells, it could even be a different sex. It is mind blowing.
I realise you jest, but it is something I've genuinely wondered.
There is speculation for example that chimerism could account for why 'homosexual genes' get passed on. A big argument against the idea that homosexuality could be at all genetic (and therefore must be nurture-driven) is that it would probably die out as naturally they don't breed so much.
Chimerism offers a plausible explanation for why that isn't the case.
A bone marrow transplant can also cause chimerism. This happened to my brother-in-law. Apparently, in this case, DNA taken from blood is different to DNA taken from hair.
A bone marrow transplant can also cause chimerism. This happened to my brother-in-law. Apparently, in this case, DNA taken from blood is different to DNA taken from hair.
That's a really good point - and we know that such scenarios aren't altogether uncommon.
It really leaves a bit of a question mark over DNA testing - for example someone who has left DNA evidence at a crime scene could be ruled out if they are tested on part of the body that has different DNA!
I wonder how aware the police etc are of the phenomena and whether they look into medical history of suspects to check for such things, or consider testing suspects for chimerism when evidence is hefty but DNA tests prove negative?
Yes I have read about this and it fascinates me also - alongside microchimerism, which is where someone has a small amount of body cells from their mother, child and maternal relatives due to exchange of body cells occurring across the placenta in pregnancy - or, bone marrow transplants and other transplants.
I have a friend who is going in for gestational surrogacy in the US, (she cannot carry a baby due to uterine problems, but intends to use her own egg), and I've heard from her that in the agency she's using, they're now taking full medical histories from the gestational carriers, to exclude any who have serious medical diseases, as since the latest research about microchimerism has come out, the reproductive technology experts are no longer sure that a baby carried by a surrogate mother who's not genetically related to it, might not still "inherit" a genetic disease from her due to michrochimerism. They think it's possible that the blood cells passing to the foetus from the surrogate, might be active enough to pass on any genetic tendencies to disease she has. They don't know yet but she said they're excluding surrogates with serious inherited illnesses now. Incidentally I've always found it hard to believe that if a woman carries a baby created by donor egg, she doesn't pass on anything of her own flesh and blood to it.
I think it's just fascinating, all the ramifications. I once had a friend who had hair which was naturally a mixture of golden blonde and auburn/darkish red; could that have been due to chimerism? I wonder if it's possible for someone to actually have two biological fathers, if they're a chimera of two embryos created from sperm from different men?
Perhaps people like me who aren't much like their parents, have chimera parents whose reproductive bits are genetically different from the rest of them - or we could even have been created from a tiny cell from some relative who was within our parents?
Yes I have read about this and it fascinates me also - alongside microchimerism, which is where someone has a small amount of body cells from their mother, child and maternal relatives due to exchange of body cells occurring across the placenta in pregnancy - or, bone marrow transplants and other transplants.
I have a friend who is going in for gestational surrogacy in the US, (she cannot carry a baby due to uterine problems, but intends to use her own egg), and I've heard from her that in the agency she's using, they're now taking full medical histories from the gestational carriers, to exclude any who have serious medical diseases, as since the latest research about microchimerism has come out, the reproductive technology experts are no longer sure that a baby carried by a surrogate mother who's not genetically related to it, might not still "inherit" a genetic disease from her due to michrochimerism. They think it's possible that the blood cells passing to the foetus from the surrogate, might be active enough to pass on any genetic tendencies to disease she has. They don't know yet but she said they're excluding surrogates with serious inherited illnesses now. Incidentally I've always found it hard to believe that if a woman carries a baby created by donor egg, she doesn't pass on anything of her own flesh and blood to it.
I think it's just fascinating, all the ramifications. I once had a friend who had hair which was naturally a mixture of golden blonde and auburn/darkish red; could that have been due to chimerism? I wonder if it's possible for someone to actually have two biological fathers, if they're a chimera of two embryos created from sperm from different men?
Perhaps people like me who aren't much like their parents, have chimera parents whose reproductive bits are genetically different from the rest of them - or we could even have been created from a tiny cell from some relative who was within our parents?
Thank you! You have blown my mind even more to the potentials of this... especially that BIB.
I need time to process that properly and ponder - brilliant post!
Thank you! You have blown my mind even more to the potentials of this... especially that BIB.
I need time to process that properly and ponder - brilliant post!
thanks yep it really is fascinating.
One thing I wonder about are the people who say they've always felt they were the opposite sex to the one their body is. Perhaps they are chimeras which resulted from two embryos of opposite sexes, but since they were born with normal-looking genitals, no one has realised it so far?
One thing I wonder about are the people who say they've always felt they were the opposite sex to the one their body is. Perhaps they are chimeras which resulted from two embryos of opposite sexes, but since they were born with normal-looking genitals, no one has realised it so far?
See this exactly what I was thinking... from gender identity issues, to bisexuality, to all manner of things that are considered mental health conditions, perhaps chimerism is playing a part.
I really can't do it justice tonight but I am going to read, think and reply!
Comments
Hahaha how would that work?
You're just doing it for the buzz.
It does in the general sense - from Greek mythology for the goat, lion, snake creature.
But in genetics, it means an individual which has cells of two or more different DNA profiles.
No it's different to that (that novel is ace BTW!).
Chimerism is where two or more separate blastocysts merge and form one individual with cells of two or more DNA profiles - way before any foetuses have developed.
The Dark Half was about a parasitic twin - where one blastocyst that was splitting to create identical twins doesn't progress correctly, usually resulting in extra body parts on the dominant twin.
! Thanks for that - it's amazing!
I was prompted to start reading up on this by some lovely poster (can't recall who sadly) suggesting chimerism when I pondered whether it would be possible for two conjoined twins to develop perfectly symmetrically, with the appearance of one individual.
That would of course be different to a chimera, but I'm fascinated by this whole subject
They did. Vanessa Feltz.
This must be why we have bisexuals.:D
I realise you jest, but it is something I've genuinely wondered.
There is speculation for example that chimerism could account for why 'homosexual genes' get passed on. A big argument against the idea that homosexuality could be at all genetic (and therefore must be nurture-driven) is that it would probably die out as naturally they don't breed so much.
Chimerism offers a plausible explanation for why that isn't the case.
Was that the one about the kid who thought he was being visited by aliens.
God i miss house the show was always interesting.
That's a really good point - and we know that such scenarios aren't altogether uncommon.
It really leaves a bit of a question mark over DNA testing - for example someone who has left DNA evidence at a crime scene could be ruled out if they are tested on part of the body that has different DNA!
I wonder how aware the police etc are of the phenomena and whether they look into medical history of suspects to check for such things, or consider testing suspects for chimerism when evidence is hefty but DNA tests prove negative?
I have a friend who is going in for gestational surrogacy in the US, (she cannot carry a baby due to uterine problems, but intends to use her own egg), and I've heard from her that in the agency she's using, they're now taking full medical histories from the gestational carriers, to exclude any who have serious medical diseases, as since the latest research about microchimerism has come out, the reproductive technology experts are no longer sure that a baby carried by a surrogate mother who's not genetically related to it, might not still "inherit" a genetic disease from her due to michrochimerism. They think it's possible that the blood cells passing to the foetus from the surrogate, might be active enough to pass on any genetic tendencies to disease she has. They don't know yet but she said they're excluding surrogates with serious inherited illnesses now. Incidentally I've always found it hard to believe that if a woman carries a baby created by donor egg, she doesn't pass on anything of her own flesh and blood to it.
I think it's just fascinating, all the ramifications. I once had a friend who had hair which was naturally a mixture of golden blonde and auburn/darkish red; could that have been due to chimerism? I wonder if it's possible for someone to actually have two biological fathers, if they're a chimera of two embryos created from sperm from different men?
Perhaps people like me who aren't much like their parents, have chimera parents whose reproductive bits are genetically different from the rest of them - or we could even have been created from a tiny cell from some relative who was within our parents?
I need time to process that properly and ponder - brilliant post!
thanks
One thing I wonder about are the people who say they've always felt they were the opposite sex to the one their body is. Perhaps they are chimeras which resulted from two embryos of opposite sexes, but since they were born with normal-looking genitals, no one has realised it so far?
See this exactly what I was thinking... from gender identity issues, to bisexuality, to all manner of things that are considered mental health conditions, perhaps chimerism is playing a part.
I really can't do it justice tonight but I am going to read, think and reply!