Chimera?

[Guest Jean Davis]

I first hear this term on a "CSI" show a couple of years ago, it never occured that perhaps this might be a plausable explaination to why we are the way we are.

Here is the Wikipedia site , and here's the main explaination.

Tetragametic chimerism

Tetragametic chimerism is a form of congenital chimerism. This condition occurs through the fertilization of two separate ova by two sperm, followed by the fusion of the two at the blastocyst or zygote stages. This results in the development of an organism with intermingled cell lines. Put another way, the chimera is formed from the merging of two nonidentical twins in a very early (zygote or blastocyst) phase. As such, they can be male, female, or hermaphroditic.

As the organism develops, it can come to possess organs that have different sets of chromosomes. For example, the chimera may have a liver composed of cells with one set of chromosomes and have a kidney composed of cells with a second set of chromosomes. This has occurred in humans, and at one time was thought to be extremely rare, though more recent evidence suggests that it is not as rare as previously believed.

This is in contrast to some non-human primates, in which chimerism is very common. Most marmosets have been found to be chimera.[citation needed]

Most will go through life without realizing they are chimeras. The difference in phenotypes may be subtle (e.g., having a hitchhiker's thumb and a straight thumb, eyes of slightly different colors, differential hair growth on opposite sides of the body, etc) or completely undetectable. Another telltale of a person being a chimera is visible Blaschko's lines.[citation needed]

Affected persons may be identified by the finding of two populations of red cells or, if the zygotes are of opposite sex, ambiguous genitalia and hermaphroditism alone or in combination; such persons sometimes also have patchy skin, hair, or eye pigmentation (heterochromia). If the blastocysts are of opposite sex, genitals of both sexes may be formed, either ovary and testis, or combined ovotestes, in one rare form of intersexuality, a condition previously known as true hermaphroditism.

Note that the frequency of this condition does not indicate the true prevalence of chimerism. Most chimera composed of both male and female cells probably do not have an intersex condition, as might be expected if the two cell populations were evenly blended throughout the body. Often, most or all of the cells of a single cell type will be composed of a single cell line, i.e. The blood may be composed prominently of one cell line, and the internal organs of the other cell line. Genitalia produce the hormones responsible for other sex characteristics. If the sex organs are homogeneous, the individual will not be expected to exhibit any intersex traits.

Natural chimeras are almost never detected unless they exhibit abnormalities such as male/female or hermaphrodite characteristics or uneven skin pigmentation. The most noticeable are some male tortoiseshell cats or animals with ambiguous sex organs.

Chimera may also show, under a certain spectrum of UV light, distinctive marks on the back resembling that of arrow points pointing downwards from the shoulders down to the lower back; this is one expression of pigment unevenness called Blaschko's lines.[1]

The existence of chimerism is problematic for DNA testing, a fact with implications for family and criminal law. The Lydia Fairchild case, for example, was brought to court after DNA testing apparently showed that her children could not be hers. Fraud charges were filed against her and her custody of her children was challenged. The charge against her was dismissed when it became clear that Lydia was a chimera, with the matching DNA being found in her cervical tissue. Another case was that of Karen Keegan, who was also in danger of losing her children, after a DNA test for a kidney transplant seemed to show she wasn't the mother of her children.[2]

The tetragametic state has important implications for organ or stem-cell transplantation. Chimeras typically have immunologic tolerance to both cell lines.

My thinking is that if we could have a kidney, liver or other body organs with a different set of chromosomes, why not the brain or a portion of the brain. Perhaps this is the explaination why we feel as we do and I was wondering if those that are seeing a therapist could ask them about this.

If this could be proven to be true it would go a long way in getting us the treatment and respect we deserve.

Anywho, it's just a thought.

LUV

Jean

[Guest Donna Jean]

My thinking is that if we could have a kidney, liver or other body organs with a different set of chromosomes, why not the brain or a portion of the brain. Perhaps this is the explaination why we feel as we do and I was wondering if those that are seeing a therapist could ask them about this.

If this could be proven to be true it would go a long way in getting us the treatment and respect we deserve.

Anywho, it's just a thought.

LUV

Jean

Good thinking, Jean...I'd also like to know more about this...

It would be wonderful to have something undeniably solid to present to the medical community that would facilitate getting covered by insurance!

HUGGS!

Donna Jean

[Guest]

Very interesting. It amazes me how many variations there are within this species.

How wierd would it be to find out that your genitalia belonged to someone else, as it were? Talk about GID!

Anybody got a blacklight?

Kat

[Guest MarciPA]

I saw that episode of CSI Myself but never thought of it in this light. Creepy episode by the way. Excellent way of thinking at it Jean. the possibilities boggle the mind. Anything that gets insurance to pay is a good thing.

M~

[Guest Astro_Liz]

Ummmm... *raises hand* I'm one. Thought y'all knew that?

[Guest Elizabeth K]

I ran into this in my research. While the Chimera condition CAN be related to intersex, most intersex are considered two twins who develped as one preson, or are otherwise ambuguous because of chomosomal abnomilaies - it seems the XXY and XYY - and other variations take place on a cellular level. BUT to have different parts of the body be XY and XX, is apparently is very rare - Halequen patterning is even rarer in humans.

It could prove out the mind chemistry, body chemistry mismatch is somewhat Chimera-like.

There are many caverns to be explored in this underground world of transsexualism.

Personally I think I was kidnapped by aliens and forced into a male body! Dang their three eyes! (I think THOSE WERE EYES...creepy)

LIZZY

[Guest ricka]

I doubt this is the cause of transgenderism but I do feel that in time science will find a biological basis for being who we are. On the spiritual side I do believe in intelligent design and that God created me as I am.

Hugs, Ricka

[Guest ~Brenda~]

Hi Jean

Very interesting idea.

Specifically, the condition that you are referring to is when one has two sets of DNA coexisting in their bodies. Although our duality can be considered as two people (or two spirits as described by the indians), we do not possess two different sets of DNA.

Interesting analogy though hon

Love

Brenda

[Guest Jean Davis]

I ran into this in my research. While the Chimera condition CAN be related to intersex, most intersex are considered two twins who develped as one preson, or are otherwise ambuguous because of chomosomal abnomilaies - it seems the XXY and XYY - and other variations take place on a cellular level. BUT to have different parts of the body be XY and XX, is apparently is very rare - Halequen patterning is even rarer in humans.

It could prove out the mind chemistry, body chemistry mismatch is somewhat Chimera-like.

There are many caverns to be explored in this underground world of transsexualism.

Personally I think I was kidnapped by aliens and forced into a male body! Dang their three eyes! (I think THOSE WERE EYES...creepy)

LIZZY

That's all good but you are only considering 2-3 of the genes that determine a persons gender or gender identity.

This article from Science Daily suggests that there is 54 genes that may be responsible for gender and/or gender identity.

LUV

Jean

[Guest Ryles_D]

I ran into this in my research. While the Chimera condition CAN be related to intersex, most intersex are considered two twins who develped as one preson, or are otherwise ambuguous because of chomosomal abnomilaies - it seems the XXY and XYY - and other variations take place on a cellular level. BUT to have different parts of the body be XY and XX, is apparently is very rare - Halequen patterning is even rarer in humans.

I didn't know most intersexed people were considered that. I thought most of them weren't. Most of the IS conditions I've seen don't seem to have anything to do with chimeraism. I have seen people with mosaicism- but that seems to be more one of the early cells dropping a chromosome (which is what causes Turner, and does happen), not two different zygotes forming and merging. There was someone who had a mesh of XX, XY, and XXY cells due to the chromosome thing- they were all genetically identical except for that. Which also means that you could, conceivably, have identical twins where one was male and one was female. That would be interesting.

It seems more common for chimeraism to happen with it all the same sex (XX or XY), and trouble comes when you get a maternity test and the kid isn't yours. There is occasionally the instance of a chimera with XX/XY who has half of each being intersexed, but it seems like most chimeras aren't.

[Guest My_Genesis]

I ran into this in my research. While the Chimera condition CAN be related to intersex, most intersex are considered two twins who develped as one preson, or are otherwise ambuguous because of chomosomal abnomilaies - it seems the XXY and XYY - and other variations take place on a cellular level. BUT to have different parts of the body be XY and XX, is apparently is very rare - Halequen patterning is even rarer in humans.

It could prove out the mind chemistry, body chemistry mismatch is somewhat Chimera-like.

There are many caverns to be explored in this underground world of transsexualism.

Personally I think I was kidnapped by aliens and forced into a male body! Dang their three eyes! (I think THOSE WERE EYES...creepy)

LIZZY

My mom had an amniocentesis when she was pregnant with me. You get a karyotype out of that, so they determined me to be XX. However, I think I may have a prostate. I have been wondering if the prostate itself could be XY and the rest of me (or at least the part they uses in the amnio) is XX. That doesn't really make sense. Because how can XX cells develop into a prostate? Seems to make more sense if it was XY, right?

[Guest Ryles_D]

My mom had an amniocentesis when she was pregnant with me. You get a karyotype out of that, so they determined me to be XX. However, I think I may have a prostate. I have been wondering if the prostate itself could be XY and the rest of me (or at least the part they uses in the amnio) is XX. That doesn't really make sense. Because how can XX cells develop into a prostate? Seems to make more sense if it was XY, right?

There's something called XX genetic male, basically a person who's genetically XX develops into a man who's indistinguishable from other males (until he goes to have children- but I think some might even be fertile). I'm pretty sure they have a prostate with XX cells. Could be wrong. I also don't think that cAIS women have prostates (XY, but they don't respond to testosterone so they develop as women)