Editing Genomic imprinting (section)

===Genetic mapping of imprinted genes===
At the same time as the generation of the gynogenetic and androgenetic embryos discussed above, mouse embryos were also being generated that contained only small regions that were derived from either a paternal or maternal source.<ref name="Cattanach and Kirk 1985">{{cite journal | vauthors = Cattanach BM, Kirk M | title = Differential activity of maternally and paternally derived chromosome regions in mice | journal = Nature | volume = 315 | issue = 6019 | pages = 496–498 | year = 1985 | pmid = 4000278 | doi = 10.1038/315496a0 | bibcode = 1985Natur.315..496C | s2cid = 4337753 }}</ref><ref name="McLaughlin 1996">{{cite journal | vauthors = McLaughlin KJ, Szabó P, Haegel H, Mann JR | title = Mouse embryos with paternal duplication of an imprinted chromosome 7 region die at midgestation and lack placental spongiotrophoblast | journal = Development | volume = 122 | issue = 1 | pages = 265–270 | date = January 1996 | pmid = 8565838 | doi = 10.1242/dev.122.1.265 }}</ref> The generation of a series of such [[uniparental disomy|uniparental disomies]], which together span the entire genome, allowed the creation of an imprinting map.<ref>{{Cite web |year=2008 |title=Mouse Imprinting Data and References |url=http://www.har.mrc.ac.uk/research/genomic_imprinting/ |url-status=dead |archive-url=https://web.archive.org/web/20120703103129/http://har.mrc.ac.uk/research/genomic_imprinting/ |archive-date=2012-07-03 |access-date=2008-07-02 |publisher=MRC Harwell |vauthors=Beechey C, Cattanach BM, Lake A, Peters J}}</ref> Those regions which when inherited from a single parent result in a discernible phenotype contain imprinted gene(s). Further research showed that within these regions there were often numerous imprinted genes.<ref name="Bartolomei and Tilghman 1997">{{cite journal | vauthors = Bartolomei MS, Tilghman SM | title = Genomic imprinting in mammals | journal = Annual Review of Genetics | volume = 31 | pages = 493–525 | year = 1997 | pmid = 9442905 | pmc = 3941233 | doi = 10.1146/annurev.genet.31.1.493 }}</ref> Around 80% of imprinted genes are found in clusters such as these, called imprinted domains, suggesting a level of co-ordinated control.<ref name="Reik and Walter 2001">{{cite journal | author1 = Reik W |author-link1 =Wolf Reik | author2=Walter J | title = Genomic imprinting: parental influence on the genome | journal = Nature Reviews. Genetics | volume = 2 | issue = 1 | pages = 21–32 | date = January 2001 | pmid = 11253064 | doi = 10.1038/35047554 | s2cid = 12050251 }}</ref> More recently, genome-wide screens to identify imprinted genes have used differential expression of mRNAs from control fetuses and parthenogenetic or androgenetic fetuses hybridized to [[gene expression profiling]] microarrays,<ref>{{cite journal | vauthors = Kobayashi H, Yamada K, Morita S, Hiura H, Fukuda A, Kagami M, Ogata T, Hata K, Sotomaru Y, Kono T | display-authors = 6 | title = Identification of the mouse paternally expressed imprinted gene Zdbf2 on chromosome 1 and its imprinted human homolog ZDBF2 on chromosome 2 | journal = Genomics | volume = 93 | issue = 5 | pages = 461–472 | date = May 2009 | pmid = 19200453 | doi = 10.1016/j.ygeno.2008.12.012 | doi-access = free }}</ref> allele-specific gene expression using [[SNP genotyping]] microarrays,<ref>{{cite journal | vauthors = Bjornsson HT, Albert TJ, Ladd-Acosta CM, Green RD, Rongione MA, Middle CM, Irizarry RA, Broman KW, Feinberg AP | display-authors = 6 | title = SNP-specific array-based allele-specific expression analysis | journal = Genome Research | volume = 18 | issue = 5 | pages = 771–779 | date = May 2008 | pmid = 18369178 | pmc = 2336807 | doi = 10.1101/gr.073254.107 }}</ref> transcriptome sequencing,<ref>{{cite journal | vauthors = Babak T, Deveale B, Armour C, Raymond C, Cleary MA, van der Kooy D, Johnson JM, Lim LP | display-authors = 6 | title = Global survey of genomic imprinting by transcriptome sequencing | journal = Current Biology | volume = 18 | issue = 22 | pages = 1735–1741 | date = November 2008 | pmid = 19026546 | doi = 10.1016/j.cub.2008.09.044 | s2cid = 10143690 | doi-access = free | bibcode = 2008CBio...18.1735B }}</ref> and in silico prediction pipelines.<ref>{{cite journal | vauthors = Luedi PP, Dietrich FS, Weidman JR, Bosko JM, Jirtle RL, Hartemink AJ | title = Computational and experimental identification of novel human imprinted genes | journal = Genome Research | volume = 17 | issue = 12 | pages = 1723–1730 | date = December 2007 | pmid = 18055845 | pmc = 2099581 | doi = 10.1101/gr.6584707 }}</ref>