RT Journal Article
SR Electronic
T1 The concerted action of Meox homeobox genes is required upstream of genetic pathways essential for the formation, patterning and differentiation of somites
JF Development
JO Development
FD The Company of Biologists Limited
SP 4655
OP 4664
DO 10.1242/dev.00687
VO 130
IS 19
A1 Mankoo, Baljinder S.
A1 Skuntz, Susan
A1 Harrigan, Ian
A1 Grigorieva, Elena
A1 Candia, Al
A1 Wright, Christopher V. E.
A1 Arnheiter, Heinz
A1 Pachnis, Vassilis
YR 2003
UL http://dev.biologists.org/content/130/19/4655.abstract
AB The paraxial mesoderm of the somites of the vertebrate embryo contains the precursors of the axial skeleton, skeletal muscles and dermis. The Meox1 and Meox2 homeobox genes are expressed in the somites and their derivatives during embryogenesis. Mice homozygous for a null mutation in Meox1 display relatively mild defects in sclerotome derived vertebral and rib bones, whereas absence of Meox2 function leads to defective differentiation and morphogenesis of the limb muscles. By contrast, mice carrying null mutations for both Meox genes display a dramatic and wide-ranging synthetic phenotype associated with extremely disrupted somite morphogenesis, patterning and differentiation. Mutant animals lack an axial skeleton and skeletal muscles are severely deficient. Our results demonstrate that Meox1 and Meox2 genes function together and upstream of several genetic hierarchies that are required for the development of somites. In particular, our studies place Meox gene function upstream of Pax genes in the regulation of chondrogenic and myogenic differentiation of paraxial mesoderm.