Masticatory hypermuscularity is not related to reduced cranial volume in myostatin-knockout mice

James Cray, Jared Kneib, Lisa Vecchione, Craig Byron, Gregory M. Cooper, Joseph E. Losee, Michael I. Siegel, Mark W Hamrick, James J. Sciote, Mark P. Mooney

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

It has been suggested recently that masticatory muscle size reduction in humans resulted in greater encephalization through decreased compressive forces on the cranial vault. Following this logic, if masticatory muscle size were increased, then a reduction in brain growth should also occur. This study was designed to test this hypothesis using a myostatin (GDF-8) knockout mouse model. Myostatin is a negative regulator of skeletal muscle growth, and individuals lacking this gene show significant hypermuscularity. Sixty-two [32 wild-type (WT) and 30 GDF-8 -/- knockout], 1, 28, 56, and 180-day-old CD-1 mice were used. Body and masseter muscle weights were collected following dissection and standardized lateral and dorsoventral cephalographs were obtained. Cephalometric landmarks were identified on the radiographs and cranial volume was calculated. Mean differences were assessed using a two-way ANOVA. KO mice had significantly greater body and masseter weights beginning at 28 days compared with WT controls. No significant differences in cranial volumes were noted between KO and WT. Muscle weight was not significantly correlated with cranial volume in 1, 28, or 180-day-old mice. Muscle weights exhibited a positive correlation with cranial volume at 56 days. Results demonstrate that masticatory hypermuscularity is not associated with reduced cranial volume. In contrast, there is abundant data demonstrating the opposite, brain growth determines cranial vault growth and masticatory apparatus only affects ectocranial morphology. The results presented here do not support the hypothesis that a reduction in masticatory musculature relaxed compressive forces on the cranial vault allowing for greater encephalization.

Original languageEnglish (US)
Pages (from-to)1170-1177
Number of pages8
JournalAnatomical Record
Volume294
Issue number7
DOIs
StatePublished - Jul 1 2011

Fingerprint

Myostatin
myostatin
Knockout Mice
muscle
Masticatory Muscles
muscles
mice
Growth
Weights and Measures
Cephalometry
Masseter Muscle
Muscles
brain
Brain
Dissection
Analysis of Variance
Skeletal Muscle
dissection
Body Weight
skeletal muscle

Keywords

  • Brain evolution
  • Hypermuscularity
  • Knockout model
  • Myostatin

ASJC Scopus subject areas

  • Anatomy
  • Biotechnology
  • Histology
  • Ecology, Evolution, Behavior and Systematics

Cite this

Cray, J., Kneib, J., Vecchione, L., Byron, C., Cooper, G. M., Losee, J. E., ... Mooney, M. P. (2011). Masticatory hypermuscularity is not related to reduced cranial volume in myostatin-knockout mice. Anatomical Record, 294(7), 1170-1177. https://doi.org/10.1002/ar.21412

Masticatory hypermuscularity is not related to reduced cranial volume in myostatin-knockout mice. / Cray, James; Kneib, Jared; Vecchione, Lisa; Byron, Craig; Cooper, Gregory M.; Losee, Joseph E.; Siegel, Michael I.; Hamrick, Mark W; Sciote, James J.; Mooney, Mark P.

In: Anatomical Record, Vol. 294, No. 7, 01.07.2011, p. 1170-1177.

Research output: Contribution to journalArticle

Cray, J, Kneib, J, Vecchione, L, Byron, C, Cooper, GM, Losee, JE, Siegel, MI, Hamrick, MW, Sciote, JJ & Mooney, MP 2011, 'Masticatory hypermuscularity is not related to reduced cranial volume in myostatin-knockout mice', Anatomical Record, vol. 294, no. 7, pp. 1170-1177. https://doi.org/10.1002/ar.21412
Cray J, Kneib J, Vecchione L, Byron C, Cooper GM, Losee JE et al. Masticatory hypermuscularity is not related to reduced cranial volume in myostatin-knockout mice. Anatomical Record. 2011 Jul 1;294(7):1170-1177. https://doi.org/10.1002/ar.21412
Cray, James ; Kneib, Jared ; Vecchione, Lisa ; Byron, Craig ; Cooper, Gregory M. ; Losee, Joseph E. ; Siegel, Michael I. ; Hamrick, Mark W ; Sciote, James J. ; Mooney, Mark P. / Masticatory hypermuscularity is not related to reduced cranial volume in myostatin-knockout mice. In: Anatomical Record. 2011 ; Vol. 294, No. 7. pp. 1170-1177.
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