中国学者Cell子刊发表感觉神经元树突发育机制

　　

　感觉神经末梢（sensory nerve ending）是感觉神经元周围突的末梢，与其他组织如表皮、肉等组成感受器，以接受内、外环境的各种刺激，并将刺激转化为神经冲动传向中枢，产生感觉。

　　感觉树突末梢如何和周围组织相互作用形成感受器目前尚不清楚。线虫PVD感觉神经元具有规则的四级树突，具有和高等哺乳动物感觉神经末梢相似的形态，是研究树突发育和神经末梢形态发生的很好模型。

　　中国科学院生物物理研究所沈康课题组通过研究发现，肌小节规则结构调控表皮半桥粒（Hemidesmosome）规则结构，进而调控表皮SAX-7/L1CAM规则条带并指导PVD四级树突（感觉末梢）生长。哺乳动物肌肉和感觉神经末梢形成的特化结构称为肌梭“muscle spindle”，和PVD感觉神经末梢与肌肉连接十分相似，但“muscle spindle”中感觉神经末梢是否也是由肌小节规则结构调控有待进一步研究。

　　5月14日，Developmental Cell 杂志在线发表了沈康课题组关于树突发育的这项研究成果，文章题为Sarcomeres Pattern Proprioceptive Sensory Dendritic Endings through Perlecan/UNC-52 in C. elegans。

　　该研究受科技部“973”、国家自然科学基金、中科院、HMMI等资助。中科院生物物理所研究生梁杏为文章第一作者，沈康和副研究员王香明为共同通讯作者。斯坦福大学研究生Xintong Dong和University of British Columbia 教授Donald G. Moerman对该研究做出了重要贡献。

　　 图：肌小节规则结构通过基底膜组分Perlecan/UNC-52调控表皮半桥粒规则结构，进而使表皮SAX-7形成规则条带，PVD感觉神经元神经末梢沿着SAX-7规则条带生长。(Liang et al. 2015, Dev. Cell)

原文摘要：

Sarcomeres Pattern Proprioceptive Sensory Dendritic Endings through UNC-52/Perlecan in C. elegans

Sensory dendrites innervate peripheral tissues through cell-cell interactions that are poorly understood. The proprioceptive neuron PVD in C. elegans extends regular terminal dendritic branches between muscle and hypodermis. We found that the PVD branch pattern was instructed by adhesion molecule SAX-7/L1CAM, which formed regularly spaced stripes on the hypodermal cell. The regularity of the SAX-7 pattern originated from the repeated and regularly spaced dense body of the sarcomeres in the muscle. The extracellular proteoglycan UNC-52/Perlecan linked the dense body to the hemidesmosome on the hypodermal cells, which in turn instructed the SAX-7 stripes and PVD dendrites. Both UNC-52 and hemidesmosome components exhibited highly regular stripes that interdigitated with the SAX-7 stripe and PVD dendrites, reflecting the striking precision of subcellular patterning between muscle, hypodermis, and dendrites. Hence, the muscular contractile apparatus provides the instructive cues to pattern proprioceptive dendrites.