17:
177:. The imprinted DLK1-GTL2 in sheep is homologous to the DLK1 gene in humans, and includes the callipyge locus. There has been evidence to show that by screening potential fathers for a mutation at the DLK1 locus one could potentially see if their child is at a higher risk for obesity. Individuals who inherit this mutant allele from their father are more likely to show signs of obesity because the DLK1 gene is key in
151:) was studied in pigs to try to determine the effects of inheritance on ham weight. The original purpose of this study was to find the connection between genetics and ham weight to try to produce pigs that were abnormally large compared to the average. Before conducting this research, it was also hypothesized that the locus for ham weight was related to the
155:
callipyge locus in sheep. After researching it was discovered that the two regions were likely unrelated due to different forms of parental inheritance exhibited in both cases and a relatively large physical distance between the loci on the chromosome. Unlike the form of paternal polar overdominance
164:
The term polar is used to describe this type of inheritance because the phenotype of one heterozygote is expressed at a level higher than other genotypes for the same locus including those displaying either homozygous geneotype. This unique form of inheritance has largely been studied in non-human
51:) where both heterozygote genotypes display a phenotype that has increased fitness regardless of the parent of origin. Studying this type of inheritance could have practical applications in preventative medicine for humans as well as a variety of other agricultural applications.
609:
Huypens, Peter; Sass, Steffen; Wu, Moya; Dyckhoff, Daniela; Tschöp, Matthias; Theis, Fabian; Marschall, Susan; Angelis, Martin Hrabě de; Beckers, Johannes (2016). "Epigenetic germline inheritance of diet-induced obesity and insulin resistance".
86:
muscle fibers. This increase is generally located in the hind quarters and torso. Muscle hypertrophy only manifests itself in the offspring approximately one month after birth. Polar overdominance shows evidence of an imprinted
524:
Boysen, T. J.; Tetens, J.; Thaller, G. (2010-10-01). "Detection of a quantitative trait locus for ham weight with polar overdominance near the ortholog of the callipyge locus in an experimental pig F2 population".
714:
Cockett, Noelle E.; Jackson, Sam P.; Shay, Tracy L.; Farnir, Frédéric; Berghmans, Stéphane; Snowder, Gary D.; Nielsen, Dahlia M.; Georges, Michel (1996). "Polar
Overdominance at the Ovine callipyge Locus".
371:
M Georges, N Cockett. The ovine callipyge locus: a paradigm illustrating the importance of non-Mendelian genetics in livestock. Reproduction, Nutrition, Development, EDP Sciences, 1996, 36 (6), pp.651-657.
27:
is a unique form of inheritance originally described in livestock, with relevant examples in humans and mice being discovered shortly after. The term polar is used to describe this type of
20:
This figure depicts a generic graphical comparison of polar over dominance and polar under dominance. Differential inheritance is shown in a parent-of-origin type fashion in this case.
219:
Wermter, Anne-Kathrin; Scherag, André; Meyre, David; Reichwald, Kathrin; Durand, Emmanuelle; Nguyen, Thuy Trang; Koberwitz, Kerstin; Lichtner, Peter; Meitinger, Thomas (2008-04-09).
381:
Bidwell, C. A.; Waddell, J. N.; Taxis, T. M.; Yu, H.; Tellam, R. L.; Neary, M. K.; Cockett, N. E. (2014-08-01). "New insights into polar overdominance in callipyge sheep".
424:
Xu, Xuewen; Ectors, Fabien; Davis, Erica E.; Pirottin, Dimitri; Cheng, Huijun; Farnir, Frédéric; Hadfield, Tracy; Cockett, Noelle; Charlier, Carole (2015-10-16).
143:
in farm animals other than sheep. After polar overdominant inheritance was discovered to be the cause of muscular hypertrophy in sheep, the
91:
displayed as the difference between the expression of heterozygote phenotypes in a parent-of-origin type fashion. It was discovered that a
221:"Preferential reciprocal transfer of paternal/maternal DLK1 alleles to obese children: first evidence of polar overdominance in humans"
508:
156:
that occurs in the ovine callipyge locus, the locus that controls ham weight operates in a maternal polar overdominant fashion.
43:. This polarity is shown as differential phenotype is only present in one of the heterozygote configurations when the recessive
92:
320:
Georges, M.; Charlier, C.; Smit, M.; Davis, E.; Shay, T.; Tordoir, X.; Takeda, H.; Caiment, F.; Cockett, N. (2004-01-01).
47:
is inherited in a parent of origin type fashion. Polar overdominance differs from regular overdominance (also known as
165:
mammals since 1996 until it was first described in humans in 2008. In humans, the inheritance of the alleles for the
136:
127:
genes which are paternally expressed proteins in skeletal muscle are a hallmark of these mutant individuals.
426:"Ectopic Expression of Retrotransposon-Derived PEG11/RTL1 Contributes to the Callipyge Muscular Hypertrophy"
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affects the gene expression of paternal allele-specific genes and several maternal allele-specific
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The first described occurrence of polar overdominance in sheep was shown after finding that a
78:. Muscle hypertrophy in the offspring is caused by an increase in the size and proportion of
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322:"Toward Molecular Understanding of Polar Overdominance at the Ovine Callipyge Locus"
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655:"Pref-1 regulates mesenchymal cell commitment and differentiation through Sox9"
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Lawson, Heather A.; Cheverud, James M.; Wolf, Jason B. (2013-09-01).
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273:"Genomic imprinting and parent-of-origin effects on complex traits"
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Encyclopedia of
Genetics, Genomics, Proteomics and Bioinformatics
71:), must be inherited from the father to cause a condition called
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124:
120:
198:- a gene occasionally expressed through polar overdominance
570:"Genetic Imprinting: Conflict at the Callipyge Locus"
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Cold Spring Harbor
Symposia on Quantitative Biology
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173:) is linked to a higher rate of obesity in the
181:, or more simply the formation of fat cells.
8:
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653:Wang, Yuhui; Sul, Hei Sook (2009-03-01).
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467:
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568:Lewis, Annabelle; Redrup, Lisa (2005).
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135:More and more studies have identified
491:Groenen, Martien A. M. (2004-01-01).
7:
367:
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266:
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147:for the human DLK1 gene (DLK1-GTL2
125:Retrotransposon-like 1 (RTL1/PEG11)
225:European Journal of Human Genetics
14:
39:is more prevalent than the other
495:. John Wiley & Sons, Ltd.
93:single-nucleotide polymorphism
1:
137:quantitative trait loci (QTL)
121:Delta-like 1 homologue (DLK1)
737:10.1126/science.273.5272.236
451:10.1371/journal.pone.0140594
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671:10.1016/j.cmet.2009.01.013
501:10.1002/047001153x.g103311
587:10.1016/j.cub.2005.04.003
527:Journal of Animal Science
131:Agricultural application
339:10.1101/sqb.2004.69.477
277:Nature Reviews Genetics
139:that show evidence of
49:heterozygote advantage
21:
539:10.2527/jas.2009-2565
191:Imprinting (genetics)
19:
238:10.1038/ejhg.2008.64
729:1996Sci...273..236C
442:2015PLoSO..1040594X
169:gene (imprinted in
109:long non-coding RNA
25:Polar overdominance
141:genomic imprinting
117:Ectopic expression
22:
533:(10): 3167–3172.
395:10.1111/age.12132
171:eutherian mammals
149:intergenic region
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69:Venus Callipyge
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283:(9): 609–617.
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37:heterozygote
31:because the
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332:: 477–484.
84:fast-twitch
76:hypertrophy
203:References
103:imprinted
679:1932-7420
640:205351366
547:1525-3163
460:1932-6203
403:1365-2052
389:: 51–61.
348:0091-7451
247:1018-4813
160:In humans
65:callipyge
55:Discovery
41:genotypes
33:phenotype
770:Genetics
764:Category
753:41491391
697:19254573
632:26974008
596:15854893
555:20581286
478:26474044
430:PLOS ONE
411:24990181
356:16117683
307:23917626
255:18398438
185:See also
145:ortholog
123:and the
113:microRNA
745:8662506
725:Bibcode
717:Science
688:2673480
469:4608697
438:Bibcode
298:3926806
119:of the
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67:(after
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73:muscle
61:mutant
45:allele
749:S2CID
636:S2CID
153:ovine
89:locus
741:PMID
693:PMID
675:ISSN
628:PMID
592:PMID
551:PMID
543:ISSN
505:ISBN
474:PMID
456:ISSN
407:PMID
399:ISSN
352:PMID
344:ISSN
303:PMID
251:PMID
243:ISSN
196:MEG3
167:DLK1
111:and
101:DIO3
97:DLK1
733:doi
721:273
683:PMC
667:doi
620:doi
582:doi
535:doi
497:doi
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