Regulation of tendon differentiation by scleraxis distinguishes force-transmitting tendons from muscle-anchoring tendons.
Development
; 134(14): 2697-708, 2007 Jul.
Article
em En
| MEDLINE
| ID: mdl-17567668
ABSTRACT
The scleraxis (Scx) gene, encoding a bHLH transcription factor, is expressed in the progenitors and cells of all tendon tissues. To determine Scx function, we produced a mutant null allele. Scx-/- mice were viable, but showed severe tendon defects, which manifested in a drastically limited use of all paws and back muscles and a complete inability to move the tail. Interestingly, although the differentiation of all force-transmitting and intermuscular tendons was disrupted, other categories of tendons, the function of which is mainly to anchor muscles to the skeleton, were less affected and remained functional, enabling the viability of Scx-/- mutants. The force-transmitting tendons of the limbs and tail varied in the severity to which they were affected, ranging from dramatic failure of progenitor differentiation resulting in the loss of segments or complete tendons, to the formation of small and poorly organized tendons. Tendon progenitors appeared normal in Scx-/- embryos and a phenotype resulting from a failure in the condensation of tendon progenitors to give rise to distinct tendons was first detected at embryonic day (E)13.5. In the tendons that persisted in Scx-/- mutants, we found a reduced and less organized tendon matrix and disorganization at the cellular level that led to intermixing of tenocytes and endotenon cells. The phenotype of Scx-/- mutants emphasizes the diversity of tendon tissues and represents the first molecular insight into the important process of tendon differentiation.
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Base de dados:
MEDLINE
Assunto principal:
Tendões
/
Músculo Esquelético
/
Fatores de Transcrição Hélice-Alça-Hélice Básicos
Limite:
Animals
Idioma:
En
Revista:
Development
Assunto da revista:
BIOLOGIA
/
EMBRIOLOGIA
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Estados Unidos