A search for quantitative trait loci exhibiting imprinting effects on mouse mandible size and shape

Heredity (Edinb). 2008 Dec;101(6):518-26. doi: 10.1038/hdy.2008.79. Epub 2008 Aug 6.


Genomic imprinting refers to the pattern of monoallelic parent-of-origin-dependent gene expression where one of the two alleles at a locus is expressed and the other silenced. Although some genes in mice are known to be imprinted, the true scope of imprinting and its impact on the genetic architecture of a wide range of morphometric traits is mostly unknown. We therefore searched for quantitative trait loci (QTL) exhibiting imprinting effects on mandible size and shape traits in a large F(3) population of mice originating from an intercross of the LG/J (Large) and SM/J (Small) inbred strains. We discovered a total of 51 QTL affecting mandible size and shape, 6 of which exhibited differences between reciprocal heterozygotes, the usual signature of imprinting effects. However, our analysis showed that only one of these QTL (affecting mandible size) exhibited a pattern consistent with true imprinting effects, whereas reciprocal heterozygote differences in the other five all were due to maternal genetic effects. We concluded that genomic imprinting has a negligible effect on these specific morphometric traits, and that maternal genetic effects may account for many of the previously reported instances of apparent genomic imprinting.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Crosses, Genetic
  • Female
  • Genomic Imprinting
  • Male
  • Mandible / anatomy & histology*
  • Mandible / metabolism*
  • Mice / anatomy & histology
  • Mice / genetics*
  • Mice, Inbred Strains
  • Organ Size
  • Quantitative Trait Loci*