Related Experiment Video
Updated: Aug 16, 2026

Assessing Species-specific Contributions To Craniofacial Development Using Quail-duck Chimeras
Published on: May 31, 2014
Pleiotropic effects on mandibular morphology II: differential epistasis and genetic variation in morphological
James M Cheverud1, Thomas H Ehrich, Ty T Vaughn
1Department of Anatomy & Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA. Cheverud@pcg.wustl.edu
Abstract:
The evolution of morphological modularity through the sequestration of pleiotropy to sets of functionally and developmentally related traits requires genetic variation in the relationships between traits. Genetic variation in relationships between traits can result from differential epistasis, where epistatic relationships for pairs of loci are different for different traits. This study maps relationship quantitative trait loci (QTLs), specifically QTLs that affect the relationship between individual mandibular traits and mandible length, across the genome in an F2 intercross of the LG/J and SM/J inbred mouse strains (N = 1045). We discovered 23 relationship QTLs scattered throughout the genome. All mandibular traits were involved in one or more relationship QTL. When multiple traits were affected at a relationship QTL, the traits tended to come from a developmentally restricted region of the mandible, either the muscular processes or the alveolus. About one-third of the relationship QTLs correspond to previously located trait QTLs affecting the same traits. These results comprise examples of genetic variation necessary for an evolutionary response to selection on the range of pleiotropic effects.
Related Concept Videos
Dihybrid Crosses
Polygenic Traits
Epistasis
Pleiotropy
Incomplete Dominance
Epistasis Analysis

