In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 100, No. 16 ( 2003-08-05), p. 9360-9365
Abstract:
Sox9 has essential roles in endochondral bone formation during axial and
appendicular skeletogenesis. Sox9 is also expressed in neural crest cells, but its function in neural crest remains largely unknown. Because many
craniofacial skeletal elements are derived from cranial neural crest (CNC) cells, we asked whether deletion of Sox9 in CNC cells by using the
Cre recombinase/ loxP recombination system would affect craniofacial
development. Inactivation of Sox9 in neural crest resulted in a
complete absence of cartilages and endochondral bones derived from the CNC. In contrast, all of the mesodermal skeletal elements and intramembranous bones
were essentially conserved. The migration and the localization of Sox9 -null mutant CNC cells were normal. Indeed, the size of branchial
arches and the frontonasal mass of mutant embryos was comparable to that of WT embryos, and the pattern of expression of Ap2 , a marker of migrating
CNC cells, was normal. Moreover, in mouse embryo chimeras Sox9 -null
mutant cells migrated to their correct location in endochondral skeletal elements; however, Sox9 -null CNC cells were unable to contribute
chondrogenic mesenchymal condensations. In mutant embryos, ectopic expression of osteoblast marker genes, such as Runx2, Osterix , and Col1a1 , was found in the locations where the nasal cartilages exist
in WT embryos. These results indicate that inactivation of Sox9 causes CNC cells to lose their chondrogenic potential. We hypothesize that
these cells change their cell fate and acquire the ability to differentiate into osteoblasts. We conclude that Sox9 is required for the determination of
the chondrogenic lineage in CNC cells.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.1631288100
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2003
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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