Editing Hybrid (biology) (section)

==As seen by different disciplines==

===Animal and plant breeding===

From the point of view of animal and plant breeders, there are several kinds of hybrid formed from crosses within a species, such as between different [[breeds]].<ref>{{cite book |last1=Wricke |first1=Gunter |last2=Weber |first2=Eberhard |date=1986 |title=Quantitative genetics and selection in plant breeding |publisher=W. de Gruyter |page=257}}</ref> Single cross hybrids result from the cross between two [[true-breeding organism]]s which produces an [[F1 hybrid]] (first filial generation). The cross between two different [[homozygous]] lines produces an F1 hybrid that is [[heterozygous]]; having two [[Allele|alleles]], one contributed by each parent and typically one is [[Dominance relationship#Dominant allele|dominant]] and the other [[Dominance relationship#Recessive allele|recessive]]. Typically, the F1 generation is also [[phenotype|phenotypically]] homogeneous, producing offspring that are all similar to each other.<ref>{{cite book |title=Principles of Molecular Medicine |editor1-last=Runge |editor1-first=Marschall S. |editor2-last=Patterson |editor2-first=Cam |publisher=Humana Press |date=2006 |isbn=9781588292025 |page=58 |url= https://books.google.com/books?id=j-_rAKRf3WwC&pg=PA58 |access-date=27 May 2017 |archive-date=15 December 2019 |archive-url= https://web.archive.org/web/20191215073850/https://books.google.com/books?id=j-_rAKRf3WwC&pg=PA58 |url-status=live}}</ref>
Double cross hybrids result from the cross between two different F1 hybrids (i.e., there are four unrelated grandparents).<ref>{{cite journal |last1=Rawlings |first1=J. O. |last2=Cockerham |first2=C. Clark |title=Analysis of Double Cross Hybrid Populations |journal=Biometrics |volume=18 |issue=2 |date=June 1962 |pages=229–244 |doi=10.2307/2527461 |jstor=2527461}}</ref>
Three-way cross hybrids result from the cross between an F1 hybrid and an inbred line. Triple cross hybrids result from the crossing of two different three-way cross hybrids.<ref>{{cite journal |last1=Thompson |first1=K. F. |title=Triple-cross hybrid kale |journal=Euphytica |date=1964 |volume=13 |issue=2 |page=173 |doi=10.1007/BF00033306 |bibcode=1964Euphy..13..173T |s2cid=30141635 |url= https://link.springer.com/article/10.1007/BF00033306 |access-date=31 August 2017 |archive-date=10 April 2017 |archive-url= https://web.archive.org/web/20170410051806/https://link.springer.com/article/10.1007/BF00033306 |url-status=live}}</ref> Top cross (or "topcross") hybrids result from the crossing of a top quality or pure-bred male and a lower quality female, intended to improve the quality of the offspring, on average.<ref>{{cite encyclopedia |title=Topcross |url= https://www.merriam-webster.com/dictionary/topcross |dictionary=Merriam-Webster |access-date=20 March 2017 |archive-date=21 March 2017 |archive-url= https://web.archive.org/web/20170321081547/https://www.merriam-webster.com/dictionary/topcross |url-status=live}}</ref>

{{anchor|population hybrid}} '''Population hybrids''' result from the crossing of plants or animals in one [[population]] with those of another population. These include interspecific hybrids or crosses between different breeds.<ref>{{cite web |last=McCarthy |first=Eugene M. |title=Hybrid Populations |url= http://www.macroevolution.net/hybrid-populations.html |website=Macroevolution |access-date=20 March 2017 |archive-date=21 March 2017 |archive-url= https://web.archive.org/web/20170321081954/http://www.macroevolution.net/hybrid-populations.html |url-status=live}}</ref> In biology, the result of crossing of two populations is called a {{anchor|synthetic population}}'''synthetic population'''.<ref>{{cite journal |last1=Grenier |first1=Cécile |last2=Cao |first2=Tuong-Vi |last3=Ospina |first3=Yolima |last4=Quintero |first4=Constanza |last5=Châtel |first5=Marc Henri |last6=Tohme |first6=Joe |last7=Courtois |first7=Brigitte |last8=Ahmadi |first8=Nourollah |title=Accuracy of Genomic Selection in a Rice Synthetic Population Developed for Recurrent Selection Breeding |journal=PLOS ONE |date=27 August 2015 |volume=10 |issue=8 |pages=e0136594 |doi=10.1371/journal.pone.0136594 |pmid=26313446 |pmc=4551487 |bibcode=2015PLoSO..1036594G |issn=1932-6203|doi-access=free}}</ref>

In [[horticulture]], the term stable hybrid is used to describe an [[annual plant]] that, if grown and bred in a small [[monoculture]] free of external [[pollen]] (e.g., an air-filtered greenhouse) produces offspring that are "true to type" with respect to phenotype; i.e., a true-breeding organism.<ref>{{cite book |editor-last=Toogood |editor-first=A. |date=1999 |title=Plant Propagation |publisher=American Horticultural Society |isbn=9780789455208 |page=[https://archive.org/details/plantpropagation00newy/page/21 21] |url= https://archive.org/details/plantpropagation00newy/page/21}}</ref>

===Biogeography===
{{further|Hybrid zone}}

Hybridization can occur in the [[hybrid zone]]s where the geographical ranges of species, subspecies, or distinct genetic lineages overlap. For example, the butterfly ''[[Limenitis arthemis]]'' has two major subspecies in North America, ''L.&nbsp;a.&nbsp;arthemis'' (the white admiral) and ''L.&nbsp;a.&nbsp;astyanax'' (the red-spotted purple). The white admiral has a bright, white band on its wings, while the red-spotted purple has cooler blue-green shades. Hybridization occurs between a narrow area across New England, southern Ontario, and the Great Lakes, the "suture region". It is at these regions that the subspecies were formed.<ref>{{cite journal |last1=Ries |first1=Leslie |last2=Mullen |first2=Sean P. |date=2008 |title=A Rare Model Limits the Distribution of Its More Common Mimic: A Twist on Frequency-Dependent Batesian Mimicry |journal=Evolution |volume=62 |issue=7 |pages=1798–803 |doi=10.1111/j.1558-5646.2008.00401.x|pmid=18410533 |s2cid=42438552}}</ref> Other hybrid zones have formed between described species of plants and animals.

===Genetics===
[[File:Gruppenweise artbildung unter spezieller berücksichtigung der gattung Oenothera (Taf. II) (7164908226).jpg|thumb|upright|''[[Oenothera lamarckiana]]'' is a permanent natural hybrid, studied intensively by the geneticist [[Hugo de Vries]]. Illustration by De Vries, 1913.]]

From the point of view of genetics, several different kinds of hybrid can be distinguished.<ref name="Rieger">{{cite book |last1=Rieger |first1=R. |last2=Michaelis |first2=A. |last3=Green |first3=M. M. |date=1991 |title=Glossary of Genetics: Classical and Molecular |edition=5th |publisher=Springer-Verlag |isbn=9780387520544 |page=[https://archive.org/details/glossaryofgeneti0000rieg/page/256 256] |url= https://archive.org/details/glossaryofgeneti0000rieg/page/256}}</ref><ref name="A2007">{{cite book |last=Allendorf |first=Fred |title=Conservation and the Genetics of Populations |date=2007 |publisher=Blackwell |page=534}}</ref>
A genetic hybrid carries two different [[allele]]s of the same [[gene]], where for instance one allele may code for a lighter coat colour than the other.<ref name="Rieger" /><ref name="A2007" /> A structural hybrid results from the fusion of [[gamete]]s that have differing structure in at least one chromosome, as a result of [[Chromosome abnormality#Structural abnormalities|structural abnormalities]].<ref name="Rieger" /><ref name="A2007" /> A numerical hybrid results from the fusion of gametes having different [[Ploidy|haploid numbers of chromosomes]].<ref name="Rieger" /><ref name="A2007" /> A permanent hybrid results when only the heterozygous [[genotype]] occurs, as in ''[[Oenothera lamarckiana]]'',<ref name="Sirks2013" /> because all homozygous combinations are lethal.<ref name="Rieger" /><ref name="A2007" /> In the early history of genetics, [[Hugo de Vries]] supposed these were [[Mutationism|caused by mutation]].<ref>{{cite book |last=De Vries |first=Hugo |author-link=Hugo de Vries |date=1901–1903 |title=Die mutationstheorie |volume=I and II |language=de |publisher=Von Veit |location=Leipzig}}</ref><ref>{{cite journal |last=de Vries |first=Hugo |author-link=Hugo de Vries |date=January 1919 |title=''Oenothera rubrinervis'': A Half Mutant |journal=Botanical Gazette |volume=67 |issue=1 |pages=1–26 |jstor=2468868 |doi=10.1086/332396 |s2cid=83752035 |url= https://zenodo.org/record/1431405 |access-date=23 August 2020 |archive-date=18 January 2021 |archive-url= https://web.archive.org/web/20210118204356/https://zenodo.org/record/1431405 |url-status=live}}</ref>

===Genetic complementation===

Genetic complementation is a hybridization test widely used in [[genetics]] to determine whether two separately isolated [[mutant]]s that have the same (or similar) [[phenotype]] are defective in the same [[gene]] or in different [[gene]]s (see [[Complementarity_(molecular_biology)|complementation]]).<ref>{{cite journal |last1=Fincham |first1=J. R. S. |date=April 1968 |title=Genetic Complementation |journal=Science Progress |volume=56 |issue=222 |pages=165–177 |oclc=239023 |pmid=4879184}}</ref>  If a hybrid organism containing the [[genome]]s of two different mutant parental organisms displays a [[wild type]] phenotype, it is ordinarily considered that the two parental mutant organisms are defective in different genes.  If the hybrid organism displays a distinctly mutant phenotype, the two mutant parental organisms are  considered to be defective in the same gene.  However, in some cases the hybrid organism may display a phenotype that is only weakly (or partially) wild-type, and this may reflect intragenic (interallelic) complementation.

===Taxonomy===
{{See also|Hybrid name}}
From the point of view of [[Taxonomy (biology)|taxonomy]], hybrids differ according to their parentage.
Hybrids between different [[subspecies]] (such as between the [[dog]] and [[Eurasian wolf]]) are called intra-specific hybrids.<ref>{{cite book |last=Allendorf |first=Fred |title=Conservation and the Genetics of Populations |date=2007 |publisher=Blackwell |pages=421–448}}</ref> Interspecific hybrids are the offspring from [[interspecies mating]];<ref>{{cite book |last=Keeton |first=William T. |date=1980 |title=Biological Science |publisher=Norton |isbn=9780393950212 |page=[https://archive.org/details/biologicalscienc00keet/page/ A9] |url= https://archive.org/details/biologicalscienc00keet/page/}}</ref> these sometimes result in hybrid speciation.<ref>{{cite book |last=Arnold |first=M. L. |title=Natural Hybridisation and Evolution |date=1996 |publisher=Oxford University Press |isbn=9780195099751 |page=232}}</ref> Intergeneric hybrids result from matings between different genera, such as between [[Domestic sheep|sheep]] and [[goat]]s.<ref>{{cite journal |last1=Kelk |first1=Dawn A. |last2=Gartley |first2=Cathy J. |last3=Buckrell |first3=Brian C. |last4=King |first4=W. Allan |title=The interbreeding of sheep and goats|journal=Canadian Veterinary Journal |date=1997 |volume=38 |issue=4|pages=235–237 |pmc=1576582 |pmid=9105723}}</ref> Interfamilial hybrids, such as [[chicken hybrids|between chickens]] and [[guineafowl]] or [[pheasant]]s, are reliably described but extremely rare.<ref>{{cite web |last1=Johnsgard |first1=Paul A. |author-link=Paul Johnsgard |title=Hybridisation & Zoogeographic Patterns in Pheasants |url= http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1017&context=johnsgard |publisher=University of Nebraska - Lincoln |access-date=20 March 2017 |ref=Paul Johnsgard Collection. Paper 17 |date=1983 |page=5 |archive-date=17 August 2017 |archive-url= https://web.archive.org/web/20170817202840/http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1017&context=johnsgard |url-status=live}}</ref> Interordinal hybrids (between different orders) are few, but have been engineered between the [[sea urchin]] ''[[Strongylocentrotus purpuratus]]'' (female) and the [[sand dollar]] ''[[Dendraster excentricus]]'' (male).<ref>{{cite book |last=Giudice |first=Giovanni |title=Developmental Biology of the Sea Urchin Embryo |url= https://books.google.com/books?id=GRYNVLi1gxgC&pg=PA171 |date=2012 |publisher=Elsevier |isbn=9780323148788 |page=171 |access-date=20 March 2017 |archive-date=11 July 2020 |archive-url= https://web.archive.org/web/20200711202450/https://books.google.com/books?id=GRYNVLi1gxgC&pg=PA171 |url-status=live}}</ref>