PT  - JOURNAL ARTICLE
AU  - Brassard, Colline
AU  - Merlin, Marilaine
AU  - Monchâtre-Leroy, Elodie
AU  - Guintard, Claude
AU  - Barrat, Jacques
AU  - Garès, Hélène
AU  - Larralle, Arnaud
AU  - Triquet, Raymond
AU  - Houssin, Céline
AU  - Callou, Cécile
AU  - Cornette, Raphaël
AU  - Herrel, Anthony
TI  - Masticatory system integration in a commensal canid: interrelationships between bones, muscles, and bite force in the red fox
AID  - 10.1242/jeb.224394
DP  - 2021 Jan 01
TA  - The Journal of Experimental Biology
PG  - jeb.224394
4099  - http://jeb.biologists.org/content/early/2021/02/20/jeb.224394.short
4100  - http://jeb.biologists.org/content/early/2021/02/20/jeb.224394.full
AB  - The jaw system in canids is essential for defence and prey acquisition. However, how it varies in wild species in comparison with domestic species remains poorly understood, yet is of interest to understand the impact of artificial selection. Here we explore the variability and interrelationships between the upper and lower jaws, muscle architecture, and bite force in the red fox (Vulpes vulpes). We performed dissections and used 3D geometric morphometric approaches to quantify shape in 68 foxes. We used a static lever model and bite force estimates were compared with in vivo measurements of ten silver foxes. Our results show strong relationships exist between the cranium and mandible and the cranium or mandible on the one hand and muscles or estimated bite force on the other hand confirming the strong integration of the bony and muscular components of the jaw system. These strong relationships are strongly driven by size. The functional links between shape and estimated bite force are stronger for the mandible, which likely reflects its greater specialisation towards biting.We then compared our results with data previously obtained for dogs (Canis familiaris) to investigate the effect of domestication. Foxes and dogs differ in skull shape and muscle physiological cross-sectional areas (PCSA). They show a similar amount of morphological variation in muscle PCSA and mandible shape, but foxes show lower variation in cranial shape. Interestingly, the patterns of covariation are not stronger in foxes than in dogs, suggesting that domestication did not lead to a disruption of the functional links of the jaw system.