Modularity as a source of new morphological variation in the mandible of hybrid mice

BMC Evolutionary Biology

Paul Alibert¹  Jean-Christophe Auffray²  Sabrina Renaud³ 

[1] Biogosciences, CNRS, Universit de Bourgogne, Dijon, France;Institut des Sciences de lEvolution, CNRS, Universit Montpellier 2, Montpellier, France;Laboratoire de Biomtrie et Biologie Evolutive, UMR 5558, CNRS, Villeurbanne, France

关键词: Mus musculus;    House mouse;    Mandible shape;    Hybridization;    Geometric morphometrics;    Transgressive phenotypes;   

DOI  :  10.1186/1471-2148-12-141

学科分类：生物科学（综合）

来源: BioMed Central

【 摘 要 】

Hybridization is often seen as a process dampening phenotypic differences accumulated between diverging evolutionary units. For a complex trait comprising several relatively independent modules, hybridization may however simply generate new phenotypes, by combining into a new mosaic modules inherited from each parental groups and parts intermediate with respect to the parental groups. We tested this hypothesis by studying mandible size and shape in a set of first and second generation hybrids resulting from inbred wild-derived laboratory strains documenting two subspecies of house mice, Musmusculus domesticus and Musmusculus musculus. Phenotypic variation of the mandible was divided into nested partitions of developmental, evolutionary and functional modules. The size and shape of the modules were differently influenced by hybridization. Some modules seemed to be the result of typical additive effects with hybrids intermediate between parents, some displayed a pattern expected in the case of monogenic dominance, whereas in other modules, hybrids were transgressive. The result is interpreted as the production of novel mandible morphologies. Beyond this modularity, modules in functional interaction tended to display significant covariations. Modularity emerges as a source of novel morphological variation by its simple potential to combine different parts of the parental phenotypes into a novel offspring mosaic of modules. This effect is partly counterbalanced by bone remodeling insuring an integration of the mosaic mandible into a functional ensemble, adding a non-genetic component to the production of transgressive phenotypes in hybrids.

【 授权许可】

CC BY