Talk:Chimera (genetics)/Archive 1

Level of Difficulty
It might be useful to include in the introduction a description that does not take advantage of discipline specific terms. The first sentence took me a while to figure out, even though I knew what all the words meant: "A chimera or chimaera is a single organism (usually an animal) that is composed of two or more different populations of genetically distinct cells that originated from different zygotes involved in sexual reproduction." Here, "populations" and "zygotes", while the correct terms, are somewhat jargonish and make it hard to quickly grasp the idea. To move this article up from a B-Class it needs to include information that is accessible to a wider audience. It could be as simple as adding a layman's definition ("in other words, ..."). The OED definition (3.d.) is much more straightforward: "An organism [...] in which tissues of genetically different constitution co-exist as a result of grafting, mutation, or some other process." Thanks! Dangriff (talk) 18:14, 4 November 2011 (UTC)

article title
Why is this article called "Chimera (genetics)" and others are "(virus)" and "(plant"). Surely this should be "(animal)", or indeed fuse all together. There is nothing more genetic about this article than the other two. path 21 July 2007

No, don't do that. "genetics" is here to differentiate this article from mythological chimeras. "virus" and "plant" are simply sub-cases of this article. Anon 9 Jan 2009 —Preceding unsigned comment added by 90.13.76.246 (talk) 15:07, 9 January 2009 (UTC)

Behavioral Genetics
Anyone have any interesting research done on human chimeras in terms of behavioral genetics? Seemingly there has been stated gender role confusion so I'm very interested in this since fraternal twins naturally are male and female, and in this case, there is one "human" outcome. Make s me feel like i'm in the X-men movie saying "human" :) --Cyberman 00:34, 8 October 2005 (UTC)

Fraternal twins are not what you seem to think they are. Although all twins who are male/female are fraternal, it is possible for fraternal twins to both be the same gender. They just look like any siblings instead of looking identical, because they came from two separate fertilized eggs instead of one fertilized egg which split. A friend of mine has twin girls who are fraternal. She carried them in the same pregnancy, but they look no more alike than any non-twin sisters do. 192.54.250.11 (talk) 21:17, 22 June 2012 (UTC)

Transsexuals
Is it worthwhile mentioning the possibility, which I believe has been raised numerous times, of transsexuals, or people with gender identity issues, being this way due to being biological chimeras where the brain is physically a different gender from the sexual organs?


 * A chimera is specifically an individual with genetic material from different zygotes. That is, it is exclusively to do with the genotype. It says nothing about the phenotype. Chevin 09:01, 1 May 2006 (UTC)


 * I disagree, Chevin. If chimerism doesn't affect phenotype, then that calls into question the part of the article stating that "such persons sometimes also have patchy skin, hair, or eye pigmentation (heterochromia)." I've heard of a particular case in which a child suffering from chimerism was male on one side of the body and female on the other, with separate skin tones corresponding to the two sexes. In this child's case, chimerism was clearly affecting not just the genetic material but the expression of those genes, as well. This Wikipedia article also mentions the creation of a chicken with a quail's brain. If this is possible, then it is certainly possible for a person with male genitalia to have a female brain, or vice versa. Nrclptkrkr41 03:44, 7 July 2006 (UTC)


 * True, but those are rare chimeras, conglomerations of two sexes. It's then that the phenotype is affected. I was looking for an article here about human chimeras, like the kind who would come up negative on a paternity/maternity test even if they are actually the father/mother. I mean, people who actually have 2 sets of DNA in their bodies. My friend's sister is like that. There was a case where a mother who applied for welfare and she was hauled into court because since she was a chimera, her maternity test came out negative. Medically speaking, a transsexual is not a chimera. Transsexuality is different from chimerism. It involves a hypothalamus that resembles the opposite sex. A chimera has 2 sets of DNA, while that is not what transsexuality is defined as. Granted, there may be some transsexuals who are genetic chimeras, but that has nothing to do with the fact that they are transsexuals. Plus, it hasn't been proven that transsexuality is genetic in the first place. So chimerism is out of the question. One is born transsexual, yes, but if the condition was genetic, then transsexuality would occur more than once in the family and there would be a gene.
 * Plus, since the transsexual is not a combination of a male and female, but rather, one gender stuck in the opposite gender's body, then the transsexual is not a "hybrid" or "chimera". By trying to call a transsexual a "chimera" just because he/she is of their sexuality, then that would be calling said transsexual a "mutant", rather than a "chimera". ForestAngel (talk) 05:18, 15 January 2008 (UTC)
 * The answers above misunderstand the question on transexuality. Suppose in utero two fertilized ova, one XX and one XY. They fuse, forming a chimera. If the subsequent course of cell-division and development results in a person having almost all XX cells throughout their body excepting some XY cells in a critical area of the brain, or is a person having almost all XY cells throughout their body excepting some XX cells in a critical area of the brain, is that an explanation as to why they desire to change the gender of their body to match the gender of their psyche? That is the question. It's not necessary to answer the question by positing that the question's asker is wrong about something (unless they really are, which isn't the case here). (But the answer to their question might well be "No, research shows that that is not explanation of transexuality, although that wouldn't be apparent WITHOUT research since it has some plausibility").


 * If it's true that the likelihood of being transexual has no correlation with being related to other transexuals, that just means that transexuality isn't the result of inherited genes. It doesn't mean it's not "genetic". For instance a typical XX mother and typical XY father have a child who is not XX and not XY. Some of the other combinations cause absolute infertility. That would be a "genetic" characteristic but you couldn't say that the cause of the person's absolute infertility was inheriting a/some gene(s) for absolute infertility from their parents. It might be (and might NOT be) the case that a predisposition to create fraternal twins who fuse in the womb runs in families. But you don't inherit the condition of BEING a fusion of two fraternal twins because one of your parents consisted of two fused fraternal twins. So the characteristics of chimerism ARE "genetic" but they are NOT "inherited". For all I know (until someone cites research to the contrary) transexualism could be a chimeric characteristic and therefore also genetic but not inherited, in a manner utterly consistent with its NOT running in families and NOT being associated with some particular gene.69.86.131.76 (talk) 11:57, 14 November 2012 (UTC)Christopher L. Simpson

Wikipedians who complain about stuff but never give it a title
There's an article in today's New Scientist about this. The comment at the top of the page:


 * Whoever wrote the following is seriously confused. To begin with, a hybrid is NOT a chimera. Species chimeras contain the cells of two or more different species of animal. Species hybrids have cells that contain nuclei that contain 2 sets of chromsomes, each from a different species. Most of the animals on the list below are hybrids, not chimeras. The one exception, the geek, is neither a hybrid nor a chimera but a type of human. Crosses between sheep and goats supposedly die in utero which, if correct, means that hybrids are not possible. It is possible to make a geep (but not a geek) by combining the embryos of sheep and goat and implanting the chimeric embryo into a host female. The resulting animal has goat cells and sheep cells combined together to make a single chimeric animal. But the goat cells remain goat cells and the sheep cells remain sheep cells. They do not fuse together to make hybrid cells.

... appears to be correct. I would like to replace the article with that at Talk:Chimera (animal) (temp)

I am not a biologist, but I will be bold and do so anyway in a day or two, if there are no objections. Evercat 23:37, 13 Nov 2003 (UTC)

I think I'm right though, ie:    - last one goes into detail on the surgical creation of chimeras...

So I may just do the change tonight after all. Evercat 00:42, 14 Nov 2003 (UTC)

Done. This comment moved from the temp page:

Yes. A great relief to read this. I never know what to do about fundamentally misinformed articles. This is a very modest and discreet way to go about it. Good information. User:Wetman

Bone Marrow/Stem Cell Transplants
People who undergo allogenic (as opposed to autologous) bone marrow or stem cell transplants also exhibit chimerism, due to their having two distinct DNAs in their bodies.

Aren't all people who have had tissue or organ transplantation from another individual considered a chimera? For instance somenoe who has had a liver or heart transplant. Bagadou (talk) 07:34, 20 June 2008 (UTC)

Agreed, heart transplantation and similar operations creates chimeras and it should be noted here. Additionally, the beginning which states that it's mostly animals should be changed. Mostly animals as opposed to.. what, plants? we can do better there. — Preceding unsigned comment added by 70.187.185.32 (talk) 05:11, 9 June 2012 (UTC)

This is the same author as above; I keep reading lines like this "from her twin brother living in her body" in this article, news articles and other places.. besides just creeping me out, as it may be intended, having residual DNA which survives inside an existing, dominant organism does not constitute a person. Nobody is living inside someone else except perhaps in some conjoined cases. Isn't that sort of deliberate creepiness against Wiki TOS? — Preceding unsigned comment added by 70.187.185.32 (talk) 05:20, 9 June 2012 (UTC)
 * Hi, I read that too and got slightly creeped out. After having read through the source, though, it turns out I just misparsed the sentence in my head: There were cells from her twin living inside her; the twin himself was separate (as normal) and long dead. I've since rephrased the sentence.NotFrank (talk) 10:36, 30 January 2014 (UTC)

Clarification needed?
Part of this article reads: Chimeras have either 4 parents (2 fertilized eggs or early embryos are fused together) or 3 parents (a fertilized egg is fused with an unfertilized egg or a fertilized egg is fused with an extra sperm).

What about cases when the two embryos come from the same two parents? (Non-identical twins). And is it possible to create a chimera from more than 2 normal embryos?


 * A fertilized egg fused with an unfertilized egg (or polar body) or a fertilized egg fused with an extra sperm results in a triploidy (3 sets of chromosomes) and would give rise to an individual with the same triploid genetic compliment in every cell. In order to be considered a chimera there would have to be different populations of cells from two or more genetically distinct individuals within the same body. Bagadou (talk) 17:35, 9 April 2009 (UTC)


 * As I understand what the article is saying, the chimera would have three or four parents, even if the sperm(s) came from one father and the egg(s) came from one mother. In the case of one with four parents, the two fathers could be the same person and the two mothers could be the same person (though likely different from the father).69.73.110.152 (talk) 17:45, 21 November 2011 (UTC)

Allophene
I think we need to do a distinction between allphene and chimera. An allophen is formed from the fusion of 2 (or more) zygotes/blastocysts. The term chimera is more general and can also apply when one put ES cells in the inner cell mass. Martious 19:07, 7 March 2006 (UTC)

This phrase "ES cell" is used but never defined. I assume this means "Embryonic stem cell" but this is certainly not obvious. PR — Preceding unsigned comment added by 65.242.114.62 (talk) 09:52, 9 March 2012 (UTC)

Also we need a list of famous Chimera's. Start the list with David Bowie!!!
 * David Bowie is not a chimera, at least if that's a reference to his eyes. He has a paralyzed pupil, which doesn't contract so it looks like it's a different color.

Occurrence Rate
Is there any known occurence rate for human chimeras? Most references simply say there are only a handful of known cases. WizardofOskemen 22:48, 6 November 2006 (UTC)


 * There are a handful of confirmed cases. No one knows how many chimeras there are in the world who haven't been identified. The one's who have been identified only know so because they took DNA tests and karyotyping. There may be thousands, maybe millions of chimeras in the world that don't know it, because human chimeras (those who aren't male/female chimeras) don't look any different than anyone else. ForestAngel (talk) 05:21, 15 January 2008 (UTC)


 * Such information would be very important. If I understand the article properly, the DNA tests of human chimera (for example tests of identity, or paternity or maternity (!)) can give wrong results. If the occurrence rate for human chimera is high, it decreases reliability of such tests (which are used for judiciary!!!), or at least imposes much more care when performing such tests. Therefore informations about researches or at least rough estimates about the numbers of human chimeras would be very interesting. (sorry for my bad English) —Preceding unsigned comment added by 193.0.84.101 (talk) 10:48, 25 June 2008 (UTC)
 * True. While chimerism might not have figured in any false convictions of accused criminals, who knows how many false exonerations of guilty culprits there have been because the DNA left at the crime-scene was from one of their two cell-populations but the DNA put on the technician's swab under court-order came from the other cell-population in their body?69.86.131.76 (talk) 11:57, 14 November 2012 (UTC)Christopher L. Simpson

Chimerism and immunity.
After reading this article,I must admit that I was quite surprised! And alot of questions came to my mind. Most of those questions are of metaphysical implications, so I'm going to spare you that... But some others are on biological implications and It would be nice if someone can answer them, and maybe they might also be worth to add to the main article? It would only be logical for them to suffer from it more frequently than normal... but the article also says that they are more receptive of donors organs... and that also makes sense... I mean is it possible to have a brain composed of both types of cells without disticntions? or maybe just large areas together? like left and right hemisphere? or maybe organs are usually issued from only one type of cells? Gaaboot 17:40, 1 December 2006 (UTC)
 * Are there any studies about chimeras and autoimmunity?
 * What is the extent of the "hybridization" of the body? (I couldn't find a better word than hybridization for this)

Next
Michael Crichton's new book, Next, mentions chimeras several times, along the lines of failed paternity tests due to a chimera father. Perhaps this should be added to the page under popular culture. —The preceding unsigned comment was added by 24.225.21.231 (talk) 03:29, 7 December 2006 (UTC).

There is a seprite page for Chimera's in pop culture that covers Next, CSI and House. --Ebnielsen (talk) 18:54, 22 October 2009 (UTC)

Virus
"The proposal is to insert human DNA into a cow's egg which has had its genetic material removed and then create an embryo by the same technique that produced Dolly the Sheep." Technically speaking, does this mean Humans are now officially classifiable as a virus?--Zerothis 16:01, 14 June 2007 (UTC)

Is this really necessary?
"It is important to realize that studies like these are being conducted in order to identify a cheap, ethical source of human embryonic stem-cells to study, from which to develop the medical cures of the future. Because of the high therapeutic potential of human embryonic stem cells and the American moratorium on using discarded embryos from in vitro fertilization clinics as well as other concerns about using human embryos directly for research, scientists are trying to find ways to find alternative paths of research."

I am as big a fan of safe and responsible exploration of stem-cell research as the next person, but does this tenuously relevant diatribe really need to be in this article. WookMuff 23:52, 8 November 2007 (UTC)

"However, increasingly realizable projects using part-human, part-animal chimeras as living factories not only for biopharmaceutical production but also for producing cells or organs (see hybridomas) for xenotransplantation raise a host of ethical and safety issues." I will remove this sentence if no one rephrases it and finds citations. It violates NPOV ("living factories") and might constiute original research ("safety issues" Really? Which ones? "a host of" ethical questions? Why that many?) The whole paragraph needs to be re-written anyway. --80.108.24.212 (talk) 18:44, 19 May 2009 (UTC)

Yes. These parts of the article were clearly written by someone biased. Although I personally agree with the writer(s), I must admit that this is, at best, loaded talk.69.73.110.152 (talk) 17:49, 21 November 2011 (UTC)

Tetragametic chimera section
This whole section needs references. The examples given as manifestations of chimerism that could go undetected - "hitchhikers thumb and one normal thumb, differential hair growth on opposite sides of the body" - where do these examples come from? They seem highly unlikely as manifestations of chimerism. If these are real examples, fine. But they sound like guesses - the lack of info in the rest of the article about the extent of the 'foreign' tissue, its incorporation into the body developmentally, the point at which it differentiates, or the ratio of the two types of cells in the body seems to suggest not much is known about it. I would've thought that chimerism would result in some different tissues but not anything like hair follicles on one side of the body only or one different thumb. You can envisage how those things might result from chimerism, but they don't seem the most likely example. What next, a mole on one cheek? Why not use examples from the known cases of the women, ie tissues sampled for the DNA tests? Developmental asymmetry is common in response to environmental stresses and the implications of asymmetry much studied. Some bits of this article seem to be suggesting that asymmetry is a feature of chimerism - this may or may not be true, but if it is going to be suggested more evidence should be given. —Preceding unsigned comment added by 202.36.134.22 (talk) 10:32, 11 December 2007 (UTC)

I can send you pictures of differential hair growth. I cannot grow chest hair on the left side of my body. and yes, I am a chimera.. — Preceding unsigned comment added by 72.83.42.57 (talk) 17:53, 13 January 2013 (UTC)

This section gives a reference (Ref 1: "Which Half Is Mommy?: Tetragametic Chimerism and Trans-Subjectivity". ) to support the contention that chimeras are not as rare as previously thought. However, this is an article written by social scientists about the philosophical definition of what it is to be a mother. I can find nothing there that supports the idea of chimeras not being as rare as previously thought. Marchino61 (talk) 02:32, 8 July 2014 (UTC)

Image
The image of the male tortoiseshell cat should probably not be included on this article without qualification that not all male tortoiseshell cats are chimeras, but rather they can also be (and I suspect more likely) the result of klinefelter's syndrome and therefore x-inactivation. Are there no good photos of known chimeras freely available? --Rkitko (talk) 03:29, 22 January 2008 (UTC)
 * I removed the image as I took the photograph and it's a female cat. Also I imagine that a better image can be found that isn't of a severely anorexic cat with jaundice.  Sabar Cont 08:28, 24 February 2008 (UTC)

Merge with Parahuman?
Merge tags have been added to Chimera (genetics) and Parahuman by an anon IP, but no discussion has been started. So I'll start it. No. Do not merge. Clearly separate topics. I will remove the tags unless anyone objects within 24 hours. Snalwibma (talk) 10:37, 29 February 2008 (UTC)

Definately not. There is a clear difference between the two, and only a small section of Chimera (genetics) has to do with parahuman. pacodataco8 (talk) 10:17 3 March 2008 (CST)


 * OK - I have removed the tags. It was tagged by an anon IP who has not apparently been back since, so that's the end of it. Snalwibma (talk) 17:31, 3 March 2008 (UTC)

Henrietta Lacks
The Henrietta Lacks article links here, but the HeLa cell line doesn't appear to match any of the definitions of chimera in this article, being a blend of human and HPV. This really isn't my expertise by a long shot, so this is a fire-and-forget comment. Just thought someone here should know in case they know how to resolve this discrepancy. –BozoTheScary (talk) 01:56, 26 March 2008 (UTC)

Article split
I propose splitting the article in to two articles: Chimera (genetics) and Chimera (fiction). Obviously all of the fiction edits on the article have very little to do with the science of genetics and they waste people's time. WriterHound (talk) 18:47, 30 July 2008 (UTC)

Too multicellular-centric
This article is far too focussed on multicellular organisms, especially mammals. A theory first proposed in the 1970s and still widely supported states that eucaryotes are chimeras that arose from a series of endosymbioses between procaryotes – see for example Evolutionary history of life -- Philcha (talk) 16:18, 30 August 2008 (UTC)


 * I agree, but there doesn't seem to be an easy solution. Should we farm out the multi-cellular information to a sub-article until someone comes along and writes the microbial stuff?  Or just slap an "expand-section" tag on the micro- section to encourage someone to redress the balance?  Martin  (Smith609 – Talk)  11:41, 31 August 2008 (UTC)


 * ✅"expand-section" -- Philcha (talk) 12:49, 31 August 2008 (UTC)


 * I wonder whether WikiProject Microbiology be able to help with the expansion, if you post a request there? Martin  (Smith609 – Talk)  15:27, 31 August 2008 (UTC)

Merge of Lydia Fairchild
Per WP:BLP1E, having an article about her simply because she is known for this one incident isn't ideal, even though she was the subject of a documentary. I propose merging the details of the case into this page, where they can be read in full context. Fences &amp;  Windows  18:28, 28 November 2009 (UTC)
 * I can't see Lydia Fairchild warranting more than a sentence or two on this article. Under WP:BLP1E, I would say the event is significant both biologically and legally and deserves an article of its own. If we didn't want a biography, we could move the article to Lydia Fairchild incident or something similar. Gobonobo  T C 04:14, 26 December 2009 (UTC)
 * I agree. Chimera (genetics) is a long article dealing with biology. The details in Lydia Fairchild are important but do not belong in the Chimera (genetics) article. Peter Chastain (talk) 09:47, 8 June 2010 (UTC)

Plural
The article uses "chimerae" in some places and "chimeras" in others. Which should be used? IanHerriott (talk) 04:57, 9 August 2010 (UTC)
 * And it sometimes uses "chimera". "Chimera" is flat-out wrong. "Chimerae" is ok, but the word is now a part of English, so most dictionaries recommend "chimeras". I am globally changing it to the latter now. ~ Lhynard (talk) 04:19, 2 April 2012 (UTC)

In popular culture section?
I saw an episode of "House" in which chimerism was featured prominently in the story line. Is this worthy of inclusion in the article? IanHerriott (talk) 04:59, 9 August 2010 (UTC)

I THINK IM A CHIMERA. BUT HOW DO I TELL FOR SURE IS THERE SOME TEST ?? —Preceding unsigned comment added by 96.46.214.207 (talk) 07:02, 28 August 2010 (UTC)


 * No. See Genetic chimerism in fiction. You should find the episode you are looking for there. 69.73.110.152 (talk) 17:52, 21 November 2011 (UTC)

simplify thesis statment
The thesis (intro) statment is in dire need of simplification. This one would only make sense to someone who already knows the subject, not someone looking to find out what a Chimera is. I'd offer an example, but I still can't figure out what's being said. Pb8bije6a7b6a3w (talk) 01:08, 14 October 2012 (UTC)

Sources for increased risk for in vitro?
I added a citation needed tag for increased risk of chimerism from in vitro fertilization. While there are case reports of individual human chimeras who happened to be conceived via in vitro fertilization (one of which is a source), I don't see any sources that actually established a link between in vitro and increased risk of chimerism through research. Please add a source if you can find one, but a quick scholarly article search turned up nothing of the sort. Silent Method (talk) 21:33, 14 November 2012 (UTC)
 * In vitro fertilization typically involves implanting numerous embryos, so I could see why it may be more likely - but I'm no expert. It would be interesting to see a source on this. Feather Jonah II (talk) 19:15, 27 January 2014 (UTC)

Psychology
Hello! I came to this article after reading something about a chimera, and was wondering if chimeras are associated with multiple personality disorder or similar psychological/neurological conditions, but the article doesn't seem to have any mention of the topic. Has there been much research into this area? It would be great if someone more familiar with the subject could add a section on this (or maybe if there is no link, a short sentence in the lead). Cheers, Feather Jonah II (talk) 19:15, 27 January 2014 (UTC)

Introduction created
I've added an introduction in mostly non-technical language; if it satisfies Wikipedian standards, please delete the "needs intro" template. --Monado (talk) 23:45, 15 December 2013 (UTC)

Merger with Chimera (plant)
In genetics, the term "chimera" is not restricted to animals; plants are included as well. Whether an organism is a plant or an animal, if it is a chimera, it is composed of genetically distinct cells. The article called Chimera (genetics) should cover both plant and animal chimeras. For this reason, Chimera (plant) should be merged here. Neelix (talk) 03:56, 22 January 2014 (UTC)

Parents?
This part of the lede doesn't sound quite right, "...the result is an organism with two sets of parents"; parents can mean distinct individuals, as in two sets of "mom & dad"  and "parent" cells as in two sets of sperm and egg; I suggest that this clause be deleted; the point this text is trying to make is better explained in the body of the article. Mirboj (talk) 05:15, 28 February 2014 (UTC)

Why are you publishing this?
When nearly everything written is about this subject "chimera" is utterly false, esp when using the definitions of words that have entries in Wikipedia and it's affiliated dictionary. This is not accurate information and unless it is written in heavily coded English, it severely detracts from a readers ability to understand genetics. I don't flag articles for deletion, but I would ask that you move this send this article through some sort of science fiction portal and incorporate it into a story, but it does not belong as written, in an encyclopedic publication. I suggest the authors do some reading to better understand how modern day scientists "look" at DNA, and how researchers use PCR, restriction enzymes, electrophoresis, western blotting, etc... I get that you guys are trying to be funny, but it isn't funny. I am not going to waste my time attempting to explain how and why many of the phenomena you claim as real events cannot and do not happen, however I would expect a solid eighth grader to understand genetics well enough to know that unless three people regularly engaged in unprotected sex together, and two of the participants were males that both consummated the act, it doesn't matter how many fertilized eggs merge, there will never be different results in regards to paternity tests unless there are two distinct fathers. They don't call them maternity tests because it isn't a mystery who the mother is when a child born. I wish I could explain to you people how damaging it is and how foolish it is when you are successful at getting another human being to believe lies that are not absolutely necessary. Please stop doing it.-Dirtclustit (talk) 09:21, 11 April 2014 (UTC)

Sorry, Dirtclustit, but you are wrong. Although I can certainly find fault with this article, the fundamental premise is correct - yes, there are people and other organisms that contain two separate sets of DNA, presumably from the merging of two embryos in utero. Thus the maternal DNA from a cheek swab may be different to that from a cervical smear in such a person. This has been demonstrated scientifically (including by some of the references in the article). Marchino61 (talk) 02:42, 8 July 2014 (UTC)

Multiple paternity
Do some chimeras exhibit multiple paternity? (I do not know.) If so, this article could use a new section about it. Although multiple paternity seems to be rare in modern human reproduction, it is common in some other animals, such as feral domestic cats: see Polyandry in nature. Acwilson9 (talk) 01:17, 9 January 2019 (UTC)

Wiki Education Foundation-supported course assignment
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Wiki Education Foundation-supported course assignment
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History of research/naming
I was scanning through trying to find when the term Chimera first came into use in genetics and was very surprised not to see anything. Is it in the article and I'm just terrible at looking? If not, does anyone know of sources available for the history of this term and associated research?&#32;-- Fyrael (talk) 16:37, 22 October 2019 (UTC)

Added New Subheadings Titled "Artificial chimerism" and "Chimera Identification"
Added new subheadings to the article: "Artificial chimerism" and "Chimera Identification".

Artificial Chimerism Artificial Chimerism falls under the artificial category in which a chimera can exist. An individual that falls under this classification possesses two different sets of genetic pedigrees: one that was inherited genetically at the time of the formation of the human embryo and the other that was intentionally introduced through a medical procedure known as transplantation.[1] Specific types of transplants that could induce this condition include bone marrow transplants and organ transplants, as the recipient’s body essentially works to permanently incorporate the new blood stem cells into it. Blood transfusions are yet another cause of artificial chimerism as it involves an individual receiving blood (transplanting blood stem cells) from a donor with a distinct genetic lineage. After successful transplantation has been complete, in the case that the recipient needs to be identified using forensics, his or her identity will match exactly that of the donor. This is due to the fact that the short sequences of DNA known as STR’s are targeted during forensic investigation and were invaded by the donor’s cells.[2] This leads to the false identification of the individual, not only by personal identification but also by sex identification if the recipient and the donor were of the opposite sex. In this case, the hair root cells would be the most appropriate sample to test since they would be the only cells not affected by the blood transfusion or transplantation procedure.[3]

An example of artificial chimerism in animals are the quail-chick chimeras. By utilizing transplantation and ablation in the chick embryo stage, the neural tube and the neural crest cells of the chick were ablated, and replaced with the same parts from a quail.[4] Once hatched, the quail feathers were visibly apparent around the wing area, whereas the rest of the chick’s body was made of its own chicken cells.

Chimera Identification Chimerism is so rare, that there have only been 100 confirmed cases in humans.[5] However, this may be due to the fact that humans might not be aware that they have this condition to begin with. There are usually no signs or symptoms for chimerism other than a few physical symptoms such as hyper-pigmentation, hypo-pigmentation, or possessing two different colored eyes. However, these signs do not necessarily mean an individual is a chimera and should only be seen as possible symptoms. Again, forensic investigation or curiosity over a failed maternity/paternity DNA test usually leads to the accidental discovery of this condition. By simply undergoing a DNA test, which usually consists of either a swift cheek swab or a blood test, the discovery of the once unknown second genome is made, therefore identifying that individual as a chimera.[6]

References Rinkevich, B. (June 2001). "Human natural chimerism: an acquired character or a vestige of evolution?". Human Immunology. 62 (6): 651–657. doi:10.1016/s0198-8859(01)00249-x. ISSN 0198-8859. PMID 11390041. Rinkevich, B. (June 2001). "Human natural chimerism: an acquired character or a vestige of evolution?". Human Immunology. 62 (6): 651–657. doi:10.1016/s0198-8859(01)00249-x. ISSN 0198-8859. PMID 11390041. von Wurmb-Schwark, Nicole; Bosinski, Hartmut; Ritz-Timme, Stefanie (January 2007). "What do the X and Y chromosomes tell us about sex and gender in forensic case analysis?". Journal of Forensic and Legal Medicine. 14 (1): 27–30. doi:10.1016/j.jcfm.2005.09.003. ISSN 1752-928X. PMID 16931101. "Developmental Biology Cinema, Le Douarin". www.sdbonline.org. Retrieved 2020-03-15. "Chimerism: Definition, Symptoms, Testing, Diagnosis, and More". Healthline. Retrieved 2020-03-15. "National Society of Genetic Counselors : Blogs : Chimerism Explained: How One Person Can Unknowingly Have Two Sets of DNA". www.nsgc.org. Retrieved 2020-03-15. Kaira Hosnedl (talk) 21:15, 10 April 2020 (UTC)

Number of confirmed chimeras is extremely misleading
Under Chimera Identification the following statement is given: "Chimerism is so rare, that there have only been 100 confirmed cases in humans." If you follow the footnote you will be directed to this website which itself links to this one. The latter states the following: "There are approximately 100 cases of chimerism recorded in medical literature" Earlier in the text on the wiki page a 1996 study about blood group chimerism is mentioned. From paper that the footnote links to: "we detected blood group chimerism in 321415 (8%) twin pairs and 12157 (21%) triplet pairs"

That sounds to me like only 100 cases were described individually and in detail. But the number of confirmed chimeras is way, waaaaay bigger. In that case I think the statement that there have only been 100 confirmed cases in humans is misleading at best and plain wrong at worst.

Scindix (talk) 02:28, 9 March 2021 (UTC)