Circular RNA(circRNA),as a kind of non-coding RNA,regulates a variety of biological functions.To explore the effect of circRNA on PEDV replication in the host porcine intestinal epi-thelial cells,this study screened and analyzed the differentially expressed circRNAs by bioinforma-tic software in African Green Monkey renal cells(Vero-E6 cells)infected by porcine epidemic di-arrhea virus(PEDV),the differentially expressed circRNA ssc_circ_PIK3C2A was identified and the secondary structure was analyzed.PCR was used to identify the ssc_circ_PIK3C2A circRNA structure,the model of PEDV-infected IPEC-J2 cells was constructed,the TCID50 test was used to validate the viral titer of PEDV.The expression of circ_PIK3C2A was detected by qRT-PCR in IPEC-J2 infected by PEDV.circ_PIK3C2A qRT-PCR was performed to detect the expression of N gene of PEDV when ssc_circ_PIK3C2A was over-expressed in IPEC-J2 cells.The results showed that ssc_circ_PIK3C2 A is a porcine circular RNA with a typical circular structure,the virus titer of PEDV reached 10-6/mL after PEDV infected IPEC-J2 cells for 48 h,the expression of circ_PIK3C2A increased extremely(P＜0.01)at 6 h after PEDV-infection,with the extension of infec-tion time,its expression gradually decreased,and the expression was the lowest at 24 h,but there was no time-dependent trend.The expression of PEDV N gene decreased significantly when ssc_circ_PIK3C2A was over-expressed in IPEC-J2 cells.In conclusion,when PEDV infects IPEC-J2 cells,the expression of porcine circ_PIK3C2A decreases,and replication of PEDV increases signifi-cantly in IPEC-J2 cells.our result provides a basis for further study of the mechanism of circular RNA on PEDV replication and its physiological activities in host cells in the future.

Circular RNA(circRNA),as a kind of non-coding RNA,regulates a variety of biological functions.To explore the effect of circRNA on PEDV replication in the host porcine intestinal epi-thelial cells,this study screened and analyzed the differentially expressed circRNAs by bioinforma-tic software in African Green Monkey renal cells(Vero-E6 cells)infected by porcine epidemic di-arrhea virus(PEDV),the differentially expressed circRNA ssc_circ_PIK3C2A was identified and the secondary structure was analyzed.PCR was used to identify the ssc_circ_PIK3C2A circRNA structure,the model of PEDV-infected IPEC-J2 cells was constructed,the TCID50 test was used to validate the viral titer of PEDV.The expression of circ_PIK3C2A was detected by qRT-PCR in IPEC-J2 infected by PEDV.circ_PIK3C2A qRT-PCR was performed to detect the expression of N gene of PEDV when ssc_circ_PIK3C2A was over-expressed in IPEC-J2 cells.The results showed that ssc_circ_PIK3C2 A is a porcine circular RNA with a typical circular structure,the virus titer of PEDV reached 10-6/mL after PEDV infected IPEC-J2 cells for 48 h,the expression of circ_PIK3C2A increased extremely(P＜0.01)at 6 h after PEDV-infection,with the extension of infec-tion time,its expression gradually decreased,and the expression was the lowest at 24 h,but there was no time-dependent trend.The expression of PEDV N gene decreased significantly when ssc_circ_PIK3C2A was over-expressed in IPEC-J2 cells.In conclusion,when PEDV infects IPEC-J2 cells,the expression of porcine circ_PIK3C2A decreases,and replication of PEDV increases signifi-cantly in IPEC-J2 cells.our result provides a basis for further study of the mechanism of circular RNA on PEDV replication and its physiological activities in host cells in the future.