Editing Genomic imprinting (section)

== Imprinted loci phenotypic signatures ==
Unfortunately, the relationship between the phenotype and genotype of imprinted genes is solely conceptual. The idea is frameworked using two alleles on a single locus and hosts three different possible classes of genotypes.<ref name="Lawson_2013">{{cite journal | vauthors = Lawson HA, Cheverud JM, Wolf JB | title = Genomic imprinting and parent-of-origin effects on complex traits | journal = Nature Reviews. Genetics | volume = 14 | issue = 9 | pages = 609–617 | date = September 2013 | pmid = 23917626 | pmc = 3926806 | doi = 10.1038/nrg3543 }}</ref> The reciprocal heterozygotes genotype class contributes to understanding how imprinting will impact genotype to phenotype relationship. Reciprocal heterozygotes have a genetically equivalent, but they are phenotypically nonequivalent.<ref>{{cite journal | vauthors = de Koning DJ, Rattink AP, Harlizius B, van Arendonk JA, Brascamp EW, Groenen MA | title = Genome-wide scan for body composition in pigs reveals important role of imprinting | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 97 | issue = 14 | pages = 7947–7950 | date = July 2000 | pmid = 10859367 | pmc = 16650 | doi = 10.1073/pnas.140216397 | bibcode = 2000PNAS...97.7947D | doi-access = free }}</ref> Their phenotype may not be dependent on the equivalence of the genotype. This can ultimately increase diversity in genetic classes, expanding flexibility of imprinted genes.<ref name="Hoeschele_2004">{{Cite book |title=Handbook of Statistical Genetics |vauthors=Hoeschele I |date=2004-07-15 |publisher=John Wiley & Sons, Ltd |isbn=0-470-02262-0 |chapter=Mapping Quantitative Trait Loci in Outbred Pedigrees |doi=10.1002/0470022620.bbc17}}</ref> This increase will also force a higher degree in testing capabilities and assortment of tests to determine the presences of imprinting.

When a locus is identified as imprinted, two different classes express different alleles.<ref name="Lawson_2013" /> Inherited imprinted genes of offspring are believed to be monoallelic expressions. A single locus will entirely produce one's phenotype although two alleles are inherited. This genotype class is called parental imprinting, as well as dominant imprinting.<ref>{{cite journal | vauthors = Wolf JB, Cheverud JM, Roseman C, Hager R | title = Genome-wide analysis reveals a complex pattern of genomic imprinting in mice | journal = PLOS Genetics | volume = 4 | issue = 6 | pages = e1000091 | date = June 2008 | pmid = 18535661 | pmc = 2390766 | doi = 10.1371/journal.pgen.1000091 | doi-access = free }}</ref> Phenotypic patterns are variant to possible expressions from paternal and maternal genotypes. Different alleles inherited from different parents will host different phenotypic qualities. One allele will have a larger phenotypic value and the other allele will be silenced.<ref name="Lawson_2013" /> Underdominance of the locus is another possibility of phenotypic expression. Both maternal and paternal phenotypes will have a small value rather than one hosting a large value and silencing the other.

Statistical frameworks and mapping models are used to identify imprinting effects on genes and complex traits. Allelic parent-of-origin influences the vary in phenotype that derive from the imprinting of genotype classes.<ref name="Lawson_2013" /> These models of mapping and identifying imprinting effects include using unordered genotypes to build mapping models.<ref name="Hoeschele_2004" /> These models will show classic quantitative genetics and the effects of dominance of the imprinted genes.