Altered myogenesis in Six1-deficient mice.
2003
Six homeoproteins are expressed in several tissues, including muscle,
during vertebrate embryogenesis, suggesting that they may be involved in
diverse differentiation processes. To determine the functions of the
Six1 gene during myogenesis, we constructed Six1 -deficient
mice by replacing its first exon with the lacZ gene. Mice lacking
Six1 die at birth because of severe rib malformations and show
extensive muscle hypoplasia affecting most of the body muscles in particular
certain hypaxial muscles. Six1 –/– embryos have
impaired primary myogenesis, characterized, at E13.5, by a severe reduction
and disorganisation of primary myofibers in most body muscles. While Myf5,
MyoD and myogenin are correctly expressed in the somitic
compartment in early Six1 –/– embryos, by E11.5
MyoD and myogenin gene activation is reduced and delayed in
limb buds. However, this is not the consequence of a reduced ability of
myogenic precursor cells to migrate into the limb buds or of an abnormal
apoptosis of myoblasts lacking Six1 . It appears therefore that
Six1 plays a specific role in hypaxial muscle differentiation,
distinct from those of other hypaxial determinants such as Pax3, cMet,
Lbx1 or Mox2 .
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
73
References
205
Citations
NaN
KQI