A search for quantitative trait loci exhibiting imprinting effects on mouse mandible size and shape.
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.
Leamy
L J
LJ
Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223, USA. ljleamy@uncc.edu
Klingenberg
C P
CP
Sherratt
E
E
Wolf
J B
JB
Cheverud
J M
JM
D000818:Animals; D003433:Crosses, Genetic; D005260:Female; D018392:Genomic Imprinting; D008297:Male; D008334:Mandible / Q000033:anatomy & histology* / Q000378:metabolism*; D051379:Mice / Q000033:anatomy & histology / Q000235:genetics*; D008815:Mice, Inbred Strains; D009929:Organ Size; D040641:Quantitative Trait Loci