Development shapes a consistent inbreeding effect in mouse crania of different line crosses

PAVLICEV M.; MITTEROECKER P.; GONZALEZ PN; ROLIAN C; JAMNICZKY H; PARDO-MANUEL VILLENA F; MARCUCIO R; SPRITZ R; HALLGRIMSSON B

JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2016 p. 474 - 488

1552-5007

Development translates genetic variation into a multivariate pattern of phenotypic variation,distributing it among traits in a non-uniform manner. As developmental processes are largely shared within species, this suggests that the heritable phenotypic variation will be patterned similarly, in spite of the different segregating alleles. To investigate developmental effect on the variational pattern in the shape of the mouse skull across genetically differentiated lines, we employed the full set of reciprocal crosses (a.k.a. diallel) between eight inbred mouse strains of the Collaborative Cross Project. We used geometric morphometrics and multivariate analysis to capture cranial size and shape changes in 8 parentals and their 54 F1 crosses. The high heterozygosity generated in the F1 crosses allowed us to compare the multivariate deviations of the F1 phenotypes from the expected mid-parental phenotypes in different haplotype combinations. In contrast to body weight, we found a high degree of non-additivedeviation in craniofacial shape. Whereas the high phenotypic and genetic divergence of parental strains manifested in high dimensionality of additive effects, the non-additive deviations exhibited lesser dimensionality and in particular a strikingly coherent direction in shape space. We interpret this finding as evidence for a strong structuring effect of a relatively small set of developmental processes on the mapping of genetic to phenotypic variation.