为了建立和应用可检测基因I型草鱼呼肠孤病毒(GCRV)的荧光定量检测方法,实验根据基因I型GCRV的s6保守序列,分别设计扩增目的条带661bp普通引物(P1、P2)、扩增目的条带159bp荧光定量引物(F1、F2)和一条探针;同时构建含有目的片段的PVAX1-S6作为标准质粒,10倍梯度稀释构建质粒拷贝数与Ct值的标准曲线(Y=-3.389X+38.076)。结果表明,此方法在3.9×10^7~3.9×10^1拷贝/uL之间相关性较好,R2为0.992,最小检测量为4拷贝/uL;且与基因Ⅱ型、Ⅲ型GCRV以及其他病原核酸无交叉反应。运用该方法检测16份草鱼出血病疑似样品,阳性结果为4份;而普通PCR检测仅2份显示阳性。本研究建立了针对基因I型GCRV的荧光定量检测方法,具有高效、特异、灵敏、可重复性强的优点,适合于目前基因I型GCRV的临床快速检测和病毒定量分析。
In order to establish TaqMan Real-Time PCR for detection of GCRV genotype I ,the primers were designed according to conservative region of S6 as follows:normal primers designed as P1 and P2 with predicted product size of 661 bp,real time primers designed as F1 and F2 with predicted product size of 159 bp, and a probe. Standard curve ( Y = - 3. 389X + 38. 076) was generated between the cycle threshold ( Ct ) and standard plasmid (PVAX1-S6) with 10-fold serial dilutions. The results showed that there was a good linear relationship between Ct value and template concentration with a detection range from 3.9 x 107 to 3.9 × 10^2 copies/uL, and the correlation coefficient reached 0. 992 while the detection limit of this method was 4 copies/uL for plasmid template. This assay had a specific detection of the GCRV genotype I , and had no detection signals to GCRV genotype II ,III and other pathogens. 16 suspected grass carp hemorrhage specimens were tested,and 2 more positive samples were detected using this established assay than normal RT-PCR. The developed TaqMan Real-Time PCR detection method for the GCRV genotype I with high efficiency, specificity, sensitivity and repeatability is available for clinical rapid detection and quantitative analysis of the GCRV genotype I.