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目的研究神经突触组装与功能调控相关基因是否参与秀丽线虫的脂肪积累调节。方法分析神经突触组装与功能调控相关基因突变体的脂肪积累变化,进而观察SNAREs syntaxin/unc-64和SNAP-25/ric-4基因与daf-2、daf-7、nhr-49、sbp-1及mdt-15所介导的信号通路在调控脂肪积累上的遗传关系。对unc-64与ric-4基因进行组织特异性活性分析,以确定它们在神经系统与肠道内对脂肪积累的影响。结果突触前为神经突触组装所必需的基因的突变并未明显影响脂肪积累。对调控神经突触功能的基因进行分析的结果显示,SNAREssyntaxin/unc-64与SNAP-25/ric-4基因均参与了脂肪积累的调节。利用苏丹黑染色与尼罗红标记法观察到unc-64与ric-4突变体肠道中脂肪积累显著增加,而unc-64与ric-4突变体中积累的脂肪颗粒并未出现尺寸的显著变化。在神经系统与肠道中,unc-64基因的表达均能显著降低unc-64突变体动物的脂肪积累,而基因ric-4在神经系统的表达则可以完全恢复ric-4突变体动物的脂肪积累。遗传分析表明,unc-64与ric-4对脂肪积累的调控独立于daf-2(IGF-I受体基因)、daf-7(TGF-β配体基因)和nhr-49(核激素受体基因),且不受daf-16基因突变的影响。进一步的研究结果显示,unc-64与ric-4可能经由ARC105/mdt-15与SREBP/sbp-1介导的信号通路来调节动物的脂肪积累进程。此外,unc-64;ric-4双突变体的脂肪积累水平要显著高于unc-64或ric-4单突变体的脂肪积累水平,提示这两个基因通过平行的遗传通路调控脂肪积累。结论质膜相关的SNAREs syntaxin/unc-64和SNAP-25/ric-4基因通过平行的遗传通路并经由ARC105/mdt-15与SREBP/sbp-1介导的信号通路来调控秀丽线虫的脂肪积累。
Objective To study whether neurofunctional assembly and functional regulation of genes involved in the regulation of fat accumulation in C. elegans. Methods The changes of fat accumulation in neuronal synaptic assembly and function-related gene mutants were analyzed. The SNAREs syntaxin / unc-64 and SNAP-25 / ric-4 genes were compared with those of daf-2, daf-7, nhr-49, sbp- 1 and mdt-15 mediated signaling pathway in the regulation of the genetic relationship of fat accumulation. Tissue-specific activity analyzes of unc-64 and ric-4 genes were performed to determine their effect on adipose accumulation in the nervous system and intestine. Results The pre-synaptic mutations required for neuronal synaptic assembly did not significantly affect fat accumulation. Analysis of genes that regulate neuronal synaptic function revealed that both SNAREssyntaxin / unc-64 and SNAP-25 / ric-4 genes are involved in the regulation of adipose accumulation. The accumulation of fat in the intestine of unc-64 and ric-4 mutants was significantly increased by Sudan black staining and Nile red labeling, whereas the accumulation of fat particles in unc-64 and ric-4 mutants did not show significant changes in size . In both the nervous system and gut, unc-64 gene expression significantly reduced fat accumulation in unc-64 mutant animals while expression of the gene ric-4 in the nervous system completely restored fat accumulation in ric-4 mutant animals . Genetic analysis showed that the regulation of fat accumulation by unc-64 and ric-4 was independent of daf-2 (IGF-I receptor gene), daf-7 (TGF-β ligand gene) and nhr-49 Gene), and not affected daf-16 gene mutation. Further studies showed that unc-64 and ric-4 may regulate the process of fat accumulation in animals through ARC105 / mdt-15 and SREBP / sbp-1-mediated signaling pathways. In addition, the fat accumulation level of unc-64; ric-4 double mutant was significantly higher than that of unc-64 or ric-4 single mutant, suggesting that these two genes regulate fat accumulation through parallel genetic pathways. Conclusions The plasma membrane-associated SNAREs syntaxin / unc-64 and SNAP-25 / ric-4 genes regulate the fat accumulation in C. elegans via parallel genetic pathways and via signaling pathways mediated by ARC105 / mdt-15 and SREBP / sbp-1 .