Talk:Chimera (genetics)

This article was the subject of a Wiki Education Foundation-supported course assignment, between 22 August 2019 and 4 December 2019. Further details are available on the course page. Student editor(s): Carroll.joseph (article contribs). Peer reviewers: Carroll.joseph. This article was the subject of a Wiki Education Foundation-supported course assignment, between 13 January 2020 and 6 May 2020. Further details are available on the course page. Student editor(s): Kaira Hosnedl (article contribs).

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? -- 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)

Definitions of chimera

Aren’t there more definitions of chimera than the one presented here?CycoMa (talk) 13:43, 26 June 2021 (UTC)

Request: Self reporting chimerism

I seem to exhibit visible chimerism, (hair is blonde and brown patches down one half of my body, Finnish epicanthic fold on one eye and not on the other). Given the amount of cases actually studied, I'd like to volunteer to contribute to any research being done. I'm also left handed and transgender (bi gender) and I'm curious if there's any links.

However, I'm having trouble finding any contacts to follow through on this. Does anyone know of any active researchers related to chimerism I could connect with?