First published online March 9, 2007
Development 134, 701e (2007)
© The Company of Biologists Limited
Teleosts flex their muscles
In amniotes, muscle progenitors develop from the dermomyotome, an
epithelium that overlays the somite. These myogenic progenitors bring about
muscle growth and are well characterised; however, in teleosts these
precursors have, until now, not been identified. Now, Devoto and colleagues
use lineage-tracing and gene-expression studies to identify a population of
cells that resides at the anterior border of zebrafish somites as the elusive
myogenic precursors
(p.1253).
Surprisingly, these pax7-expressing precursors remain
undifferentiated before they migrate to the outer lateral surface of the
somite, where they initiate myotome growth. Unusually, anterioposterior somite
patterning can, as shown in this study, generate subsequent myogenic precursor
mediolateral patterning. While some progenitor cells remain at the surface of
the myotome, others penetrate the slow-twitch muscle layer, moving between
cells, to contribute to fast-twitch musculature. Even though the occurrence of
external myogenic precursors is now shown to be conserved among vertebrate
lineages, the origin and movement of the teleost precursor cells is
unexpectedly different.
Related articles in Development:
- Dynamic somite cell rearrangements lead to distinct waves of myotome growth
- Frank Stellabotte, Betsy Dobbs-McAuliffe, Daniel A. Fernández, Xuesong Feng, and Stephen H. Devoto
Development 2007 134: 1253-1257.
[Abstract]
[Full Text]
