细胞自噬相关基因Atg5在细胞自噬过程中发挥重要作用,其功能丧失损坏神经发生和轴突再生.涡虫是研究脑再生的良好模型,其头部切除后1周就能再生出1个新的脑结构.因此,研究Atg5基因在涡虫脑再生中的作用对探究自噬调控神经再生具有重要意义.本研究克隆了日本三角涡虫Atg5基因(DjAtg5)的全长cDNA序列,并利用RNAi技术研究了其在涡虫再生中作用.结果 显示,DjAtg5 cDNA全长1014 bp,编码284个氨基酸.DjATG5含有ATG5蛋白质家族的Pfam结构域和高度保守的ATG5-ATG12相互结合位点.切割虫体后,DjAtg5表达显著增加.再生3～5天,其转录本主要在新再生的脑结构表达.但是,敲降DjAtg5并未引起涡虫脑再生异常,且对涡虫干细胞的增殖也未见明显影响.研究结果表明,DjAtg5参与涡虫脑结构的重新形成,但不是涡虫再生的重要调控因子.然而,自噬抑制剂3-MA能够阻止涡虫再生,说明细胞自噬机制对涡虫再生非常重要.“,”Autophagy-related gene 5 (Atg5) plays an essential role in autophagy,the loss of its function impairs neurogenesis and axon regeneration.However,the biological function of Atg5 has not been char-acterized in planarian.Planarian is an ideal model for the study of brain regeneration.It can regenerate a new brain de novo in 1 week following amputation.To explore the role of Atg5 in planarian brain regenera-tion,we dissected the molecular characteristics of Atg5 in planarian Dugesia japonica (DjAtg5) and ex-amined its function by RNAi.The full-length cDNA of DjAtg5 is 1014 bp encoding 284 amino acids.The deduced amino sequence of DjAtg5 contains the functional Pfam domain of ATG5 and highly conserved residues for ATG5-ATG12 interaction.After amputation,the transcrips of DjAtg5 are increased and main-ly distributed in the newly regenerated brain on day 3-5 of regeneration.However,knockdown of DjAtg5 by RNAi does not impair the regeneration ability and brain structure reformation,nor affects the neoblasts proliferation.Our results suggest that DjAtg5 participates in re-formation of planarian brain structure fol-lowing amputation,but it is not an important regulator for planarian regeneration.However,autophagy in-hibitor 3-MA can block planarian regeneration,which suggests that autophagy is necessary for planarian regeneration.