LncRNA CR43356-E2F1 Feedback Regulates G1-S Transition In Drosophila

In organisms,the maintenance of normal cell growth,development and cell homeostasis is necessary for survival.During those progresses,the regulation of cell cycle is very important and fundamental for development.The cell cycle is mainly divided into four phases,namely G1 phase,S phase,G2 phase and M phase,besides of these four phases,there is also a G0 phase,in which is the cell is quiescent cell.During the procession of cell cycle,the transition of G1-S is a process from material preparation to DNA synthesis,which is crucial for cell proliferation,and the disrupt of this transformation process can leads to abnormal developmental or diseases.E2F transcription family is a group of protein which play important role in regulating gene expression in DNA replication,DNA repair and cell cycle regulation e2f1 is a member of the E2F transcription factor family and plays an important role in cell cycle regulation.rbf,as an inhibitor of e2f1,phosphorylated in the late G1 phase by CDK2,and releases e2f1.The released e2f1 causes transcriptional activation of downstream factors,thus initiating DNA replication and cell cycle process,and promoting cell transition from G1 to S.E2F2 is another member of the E2F family,be as a member of the DREAM complex and plays a role in inhibiting this signaling pathway.Previously,we collected the w1118 and e2f1 mutant fruit flies which in larvae 3,extracted the RNA from both the physiological conditions and irradiated conditions,after RNA-SEQ assay,we screened the differentially expressed lncRNAS,and identify new IncRNAs which we can study their functions related to e2f1.We got a lncRNA by our RNA-seq assay:CR43356,was down-regulated in e2f1 mutant flies.I also verified this data by RT-qPCR assay,and the results were consistent with RNA-seq assay.Subsequent experiments was study by CR43356-/-fruit fly strain.Previous tests of survival also found that the CR43356 mutant flies showed sensitivity to radiation exposure at different doses.This also gives us a little enlightenment for the follow-up researchPreviously,we also tested the G2/M checkpoint by anti-pH3 stain and the results showed that the CR43356 mutant drosophila had no G2/M checkpoint defectsAccording to the current research status and preliminary data.In this study,Drosophila Melanogata was used as a model animal to study the regulatory relationship between long non-coding RNA CR43356 and e2f1.The transcription and protein levels of e2f1 in CR43356-/-drosophila and its role in cell cycle and apoptosis were investigated to study how CR43356 regulates e2f1.The results showed that CR43356 could negatively regulate e2f1 level which can affect cell transition from G1 to S.