lncRNA具有广泛的生物学功能，有关它们在生物体内功能的研究还较少，并且lncRNA与关键因子E2F1如何协同调节细胞周期进程和应答DNA损伤还缺少研究。使用果蝇模式生物，本研究系统分析了e2f1突变果蝇中lncRNA的表达变化，发现lncRNA CR43356在e2f1突变果蝇中表达下调；利用已建立的lncRNA敲除果蝇进行二次筛选，发现e2f1基因在CR43356敲除果蝇中表达显著上升，并且E2F1蛋白质的表达水平也升高。RACE测序证实CR43356存在3个转录本。CR43356敲除果蝇对DNA损伤高度敏感，辐照后生存率降低，出现DNA损伤导致的凋亡细胞增多、S期检验点缺陷。本研究从生物体水平深入研究CR43356-E2F1协同调节细胞周期进程和应答DNA损伤的功能和作用机制，加深对E2F1调节机制的了解，具有重要的科学意义。

It is known that lncRNAs have diversified functions, however their roles in vivo are still not clear, and how E2F1, a key transcriptional factor, coordinates with lncRNAs to regulate cell cycle progression and DNA damage response is still lacking. Using Drosophila malanogaster as a model animal, we found lncRNA CR43356 was differentially expressed in e2f1 mutated flies. Using previously established CR43356 knock-out fly, we found that e2f1 expression was significantly increased in CR43356 mutant. Moreover, E2F1 protein level was also greatly increased in CR43356 mutant. We identified 3 transcripts of CR43356 using the RACE-seq method. Furthermore, the CR43356 knock-out flies were hypersensitive to irradiation, showing greatly reduced viability, increased apoptosis, and S phase checkpoint defect. In this study, we will investigate the underlying mechanisms of how lncRNA CR43356-E2F1 work coordinately to regulate cell cycle progression and DNA damage response, to improve our understanding towards regulation of E2F1, and provide novel knowledge to understand cell cycle regulation and genome maintenance.