Embryonic and postnatal development of masticatory and tongue muscles

Abstract

This review summarizes findings concerning the unique developmental characteristics of mouse head muscles (mainly the masticatory and tongue muscles) and compares their characteristics with those of other muscles. The developmental origin of the masticatory muscles is the somitomeres, whereas the tongue and other muscles, such as the trunk (deep muscles of the back, body wall muscles) and limb muscles, originate from the somites. The program controlling the early stages of masticatory myogenesis, such as the specification and migration of muscle progenitor cells, is distinctly different from those in trunk and limb myogenesis. Tongue myogenesis follows a similar regulatory program to that for limb myogenesis. Myogenesis and synaptogenesis in the masticatory muscles are delayed in comparison with other muscles and are not complete even at birth, whereas the development of tongue muscles proceeds faster than those of other muscles and ends at around birth. The regulatory programs for masticatory and tongue myogenesis seem to depend on the developmental origins of the muscles, i.e., the origin being either a somite or somitomere, whereas myogenesis and synaptogenesis seem to progress to serve the functional requirements of the masticatory and tongue muscles.

The differentiation and morphogenesis of craniofacial muscles

“…Intrinsic laryngeal and tongue muscles are derived, respectively, from rostral and caudal occipital somites (somites 1-5) in amphibians (Piatt, 1938), birds (Hammond, 1965;Hazelton, 1972;Noden, 1983b;Huang et al, 1997Huang et al, , 1999Couly et al, 1992), and mammals (Yamane, 2005). Their precursors break away from the lateral myotomes of these somites, then coalesce ventrolateral to somite 4 where they form the hypoglossal cord (Figs.…”

Effects of Excessive Retinoic Acid on C2C12 Myogenesis

“…Skeletal myogenesis from progenitor cells to mature myofibers undergoes six phases, including specification, migration, proliferation, determination, differentiation and maturation 12) . There are specific regulatory mechanisms involved in these phases.…”

TGFbeta3 is expressed in differentiating muscle of the embryonic mouse tongue

“…Tongue muscle progenitor cells undergo commitment in the occipital somites (somites 2 ~5) between embryonic days (E) 8 and E11 (Mayo et al, 1992). They migrate to the first branchial arch between E9 and E11, and become myoblasts (Mayo et al, 1992) before fusing to form myotubes between E13 and E15 (Yamane, 2005;Yamane et al, 2000a). These myotubes then mature to fast-twitch myofibers between E15 and birth (Yamane, 2005;Yamane et al, 2000a).…”