Editing Chimera (genetics) (section)

====Origins====
There are multiple reasons to explain the occurrence of plant chimera during the plant recovery stage:

# The process of shoot [[organogenesis]] starts from the multicellular origin.<ref>{{cite journal |last1=Zhu |first1=X. |last2=Zhao |first2=M. |last3=Ma |first3=S. |last4=Ge |first4=Y. |last5=Zhang |first5=M. |last6=Chen |first6=L. |name-list-style=amp| title=Induction and origin of adventitious shoots from chimeras of Brassica juncea and Brassica oleracea | journal=Plant Cell Reports | year=2007 | pages=1727–1732 | volume=26 | issue=10 | doi=10.1007/s00299-007-0398-4|pmid=17622536 |s2cid=23069396}}</ref>
# The endogenous tolerance leads to the ineffectiveness of the weak selective agents.
# A self-protection mechanism (cross protection). Transformed cells serve as guards to protect the untransformed ones.<ref>{{cite journal |vauthors=Park SH, Rose SC, Zapata C, Srivatanakul M | title= Cross-protection and selectable marker genes in plant transformation. | journal= In Vitro Cellular & Developmental Biology – Plant| year=1998 | pages=117–121 | volume=34 | issue=2 | doi= 10.1007/BF02822775 | s2cid= 30883689}}</ref>
# The observable characteristic of transgenic cells may be a transient expression of the marker gene. Or it may due to the presence of agrobacterium cells.{{Citation needed|date=January 2017}}

=====Detection=====
Untransformed cells should be easy to detect and remove to avoid chimeras. This is because it is important to maintain the stable ability of the transgenic plants across different generations. Reporter genes such as [[GUS reporter system|GUS]] and [[Green Fluorescent Protein]]<ref>{{cite journal |last1=Rakosy-Tican |first1=E. |last2=Aurori |first2=C. M. |last3=Dijkstrav |first3=C. |last4=Thieme |first4=R. |last5=Aurori |first5=A. |last6=Davey |first6=M. R. |name-list-style=amp | title=The usefulness of the gfp reporter gene for monitoring Agrobacterium-mediated transformation of potato dihaploid and tetraploid genotypes | journal=Plant Cell Reports | year=2007 | pages=661–671 | volume=26 | issue=5 | doi=10.1007/s00299-006-0273-8|pmid=17165042 |s2cid=30548375}}</ref> (GFP) are used in combination with plant selective markers (herbicide, antibody etc.). However, GUS expression depends on the plant development stage and GFP may be influenced by the green tissue autofluorescence. [[Quantitative PCR]] could be an alternative method for chimera detection.<ref>{{cite journal | last1=Faize |first1=M. | last2=Faize |first2=L. | last3=Burgos |first3=L. | title=Using quantitative real-time PCR to detect chimeras in transgenic tobacco and apricot and to monitor their dissociation | journal=BMC Biotechnology | year=2010 | pages=53 | volume=10 | issue=1 | doi=10.1186/1472-6750-10-53| pmid=20637070 | pmc=2912785 | doi-access=free }}</ref>