# name
Expression of Myosin Heavy Chain Isoform mRNA Transcripts in the Masseter and Medial Pterygoid Muscles

# metadata.dc.description.abstract[].value
Both the masseter and medial pterygoid muscles elevate the mandible, raising the lower jaw by acting simultaneously on
the lateral and medial surfaces of the mandibular ramus. Nevertheless, electromyographic studies indicate that these muscles, as well as the
superficial and deep heads of the masseter, act in a different way during mastication. We have analyzed by real time quantitative polymerase
chain reaction (RT-qPCR) the expression of myosin heavy chain (MHC) isoforms in the masseter and medial pterygoid muscles in humans in
order to identify possible differences in the expression patterns that may be related to functional differences identified with electromyography.
Our findings indicate that the expression pattern of MHC isoforms in the two muscles is characteristic of fast and powerful phasic muscles. We
have also observed a high percentage of expression of the MHC-IIx isoform and the expression of the MHC-M isoform at the mRNA level in
both muscles, an isoform that does not translate into protein in the masticatory muscles of humans. The high percentage of expression of the
MHC-IIx isoform in humans can be related to a high contractile speed of the masseter and medial pterygoid in humans. On the other hand, the
low percentage of expression of the MHC-M isoform at the mRNA level in both muscles can be related to the complex evolutionary process that
has reduced the size and force of the masticatory muscles in humans.

# metadata.dc.relation.ispartof[].value
International Journal of Morphology, 2021, vol. 39, num.5, p. 1406-1411

# metadata.dc.rights[].value
cc-by-nc (c)  Ciurana, Neus et al., 2021

# metadata.dc.source[].value
Articles publicats en revistes (Cirurgia i Especialitats Medicoquirúrgiques)

# metadata.dc.title[].value
Expression of Myosin Heavy Chain Isoform mRNA Transcripts in the Masseter and Medial Pterygoid Muscles