Barx1 represses joints and promotes cartilage in the craniofacial skeleton.

ABSTRACT: The evolution of joints, which afford skeletal mobility, was instrumental in vertebrate success. Here, we explore the molecular genetics and cell biology that govern jaw joint development. Genetic manipulation experiments in zebrafish demonstrate that functional loss, or gain, of the homeobox-containing gene barx1 produces gain, or loss, of joints, respectively. Ectopic joints in barx1 mutant animals are present in every pharyngeal segment, and are associated with disrupted attachment of bone, muscles and teeth. We find that ectopic joints develop at the expense of cartilage. Time-lapse experiments suggest that barx1 controls the skeletal precursor cell choice between differentiating into cartilage versus joint cells. We discovered that barx1 functions in this choice, in part, by regulatin

SUBMITTER: Nichols JT 

PROVIDER: S-EPMC3678344 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature