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Imprinted QTL in farm animals: a fortuity or a common phenomenon?

Part 1. Genetics

1.3. Epigenetics

Short Specialist Review

  1. Martien A. M. Groenen

Published Online: 15 NOV 2005

DOI: 10.1002/047001153X.g103311

Encyclopedia of Genetics, Genomics, Proteomics and Bioinformatics

Encyclopedia of Genetics, Genomics, Proteomics and Bioinformatics

How to Cite

Groenen, M. A. M. 2005. Imprinted QTL in farm animals: a fortuity or a common phenomenon?. Encyclopedia of Genetics, Genomics, Proteomics and Bioinformatics. 1:1.3:35.

Author Information

  1. Wageningen University, Wageningen, The Netherlands

Publication History

  1. Published Online: 15 NOV 2005

Abstract

Studies aimed at the identification of genes underlying quantitative traits (quantitative trait loci or QTL) increasingly take into account epistatic and epigenetic effects as well. The population structure and the outbred nature of most livestock breeds make these species particularly well suited to address these genetic effects. Currently, the causative mutations for two imprinted loci have been described in livestock species. In sheep, the callipyge mutation affects a regulatory element located between the imprinted genes DLK1, PEG11, GTL2 and MEG8, and in pigs a mutation has been identified in a CpG island located within intron 3 of the maternally imprinted gene IGF2. A growing number of studies have identified QTL that show evidence of imprinting. Although several of the identified imprinted QTL effects are likely to be spurious effects, these studies provide accumulating evidence that imprinting plays a more important role in multifactorial traits than previously anticipated. For animal breeding practice, the identification of major imprinted loci affecting body composition has several implications and calls for a revision of the breeding value evaluation methods and breeding strategies that are currently solely based on the assumption of a large number of genes showing Mendelian expression.

Keywords:

  • imprinting;
  • QTL;
  • IGF2;
  • callipyge;
  • pig;
  • growth