XPR1在果蝇三龄幼虫神经肌肉接头中功能初探

Preliminary study on the function of XPR1 in the neuromuscular junction of Drosophila melanogaster third larva

异嗜性和多向性逆转录病毒受体(xenotyopic and polytropic retrovirus receptor,xpr1)是原发性家族性脑钙化(primary familial brain calcification,PFBC)的致病基因之一,PFBC患者常会出现步态紊乱以及认知障碍等症状.xpr1编码一种磷酸盐输出蛋白,在维持脑内磷酸盐的平衡中发挥重要作用.经我们研究发现,XPR1在果蝇三龄幼虫的神经肌肉接头(neuromuscular junction,NMJ)中也有分布,并且对NMJ的形态具有一定调控作用.在敲除xpr1的果蝇中,NMJ扣结数目未发生改变,但是平均面积变小了.在xpr1无功能突变体突触后的肌肉系统中高表达野生型xpr1不能挽救该表型,但是在其突触前的神经系统中高表达xpr1却可以完全挽救该表型,我们认为XPR1对NMJ的调控作用是通过其在神经系统中的功能实现的.

xpr1(xenotyopic and polytropic retrovirus receptor)is one of the causative genes of primary familial brain calcification(PFBC),patients often experience movement disorders(MD)and cognitive impairment.xpr1 encodes a phosphate export protein that plays an important role in maintaining phosphate balance in the brain.In this study,it was found that XPR1 was also distributed in the neuromuscular junction(NMJ)of the third instar larvae of Drosophila,and had a certain regulation effect on the morphology of NMJ.In xpr1-flies,the number of boutons did not change,but the size of NMJ was smaller.Overexpression of wild-type xpr1 in the muscular system could not save the phenotype,but overexpression of wild-type xpr1 in the nervous system could completely save the phenotype.We believe that the regulation of NMJ by XPR1 is realized through its function in the nervous system.