Prenatal development of skull and brain in a mouse model of growth restriction

BARBEITO - ANDRES J; GONZALEZ PN; HALLGRÍMSSON B

Revista Argentina de Antropología Biológica

Asociación de Antropología Biológica Argentina

Año: 2016 vol. 18

1514-7991

Patterns of covariation result from the overlapping effect of several developmental processes. By perturbing certain specific developmental processes, experimental studies contribute to a better understanding of their particular effects on the generation of phenotype. The aim of this work was to analyze the interactions among morphological traits of the skull and the brain during late prenatal life (18.5 days postconception) in mice exposed to maternal protein undernutrition. Images from the skull and brain were obtained through micro-computed tomography and 3D landmark coordinates were digitized in order to quantify shape and size of both structures with geometric morphometric techniques. The results highlight a systemic effect of protein restriction on the size of the skull and the brain, which were both significantly reduced in the undernourished group compared to control group. Skull shape is partially explained by brain size, and patterns of shape variation were only partially coincident with previous reports for other ontogenetic stages, suggesting that allometric trajectories across pre- and postnatal ages change their directions. Within the skull, neurocranial and facial shape traits covaried strongly, while subtle covariation was found between the shape of the skull and the brain. These findings are in line with former studies in mutant mice and reveal the importance of carrying out analyses of phenotypic variation in a broad range of developmental stages. The present study contributes to the basic understanding of epigenetic relations among growing tissues and has direct implications for the field of paleoanthropology, where inferences about brain morphology are usually derived from skull remain.