Complete Genome Sequence Analysis Of A Pigeon Circovirus And Establishment Of Sybr Green Ⅰ Fluorescent Quantitative Detection Method

Pigeon Circovirus(Pi CV)belongs to Circoviridae,Pigeon circovirus is a kind of DNA virus with single strand and circular shape.Pi CV has a high infection rate in racing pigeons and meat pigeons,and it is easy to infect young pigeons aged from 2 to 12 months.Circovirus infection of pigeon is a contact infectious disease and immunosuppressive disease,which mainly causes non-specific clinical symptoms of pigeons.In this study,PCR detection was performed on liver samples collected from a pigeon field in Hohhot city.The positive samples were selected for whole-genome amplification,and the whole genome sequence with length of 2035 bp was obtained,including two main open reading frames(ORFs).Picv-hhht20 isolates were analyzed from the homology and genetic evolution tree of the whole Pi CV genome sequence.The diversity of Pi CV genome was confirmed.In order to establish a rapid diagnostic method for pigeon circovirus(Pi CV),a pair of specific primers were designed and synthesized according to the conserved sequence of Cap gene of the amplified Pi CV,and a quantitative PCR method was established for Pi CV detection.The results showed that the method had a good linear correlation in the range of1× 102-1 ×107copies/μL under the optimal reaction conditions,and the linear correlation coefficient was 0.9846.The minimum detection rate was 1×102copies/μL,which was 100 times more sensitive than conventional PCR.The specificity was good and there was no cross-reaction with other commonly infected pigeon diseases.Repeatability evaluation showed that the coefficient of variation within and between batches was less than 2%.The positive rate of Pi CV was 75.7%,higher than that of conventional PCR(54.1%),showing the good applicability of this method.It can be applied to the rapid detection of Pi CV and provide strong technical support for the timely prevention and control of Pi CV.