Role of Trps1 in temporomandibular development

毛鼻指关节综合征（TRPS）的患者表现出特征性的面部外观，包括梨形鼻和小颌。在大多数情况下，TRPS是由TRPS1基因突变引起的。为了了解TRPS患者面部表型出现的机制，我们检查了Trps1基因敲除小鼠的颅面发育。在其胚胎阶段检查敲除小鼠，因为该KO幼仔在其出生后不久死亡。Trps1在颞下颌发育的整个胚胎阶段都有表达。KO小鼠下颌骨发育缺陷，特别是在其近端区域。关节盘、上下关节腔在突变体中从未形成。同时，髁突软骨的细胞增殖也明显减少。

Patients of Trichorhinophalangeal syndrome (TRPS) exhibit characteristic facial appearance which includes pear-shape nose and micrognathia (small jaw). In most of the case, TRPS results from mutation in the gene, TRPS1. In order to understand the mechanisms of the appearance of the facial phenotype in the TRPS patients, we examined the craniofacial development of the Trps1 knockout mice. The knockout mice were examined during its embryonic stage since this KO pups die soon after its birth. Trps1 was expressed throughout the embryonic stages of temporomandibular development. KO mice showed defects in mandibular bone development, especially in its proximal region. Articular disc, upper and lower joint cavities were never formed in the mutants. Also, the cellular proliferation at the condylar cartilage was significantly decreased.