Expression Of EnJSRV And Hyal-2 On Immune Organs Of The Fetus And The Lamb

The aim of this study was to investigate the function of enJSRV and the immunology mechanism why can not detected circulating antibody in infected sheep. Primers were designed on the basis of published enJSRV and Hyal-2 sequences in GeneBank. Gestation day 70 fetus, gestation day 130 fetus and 3d newborn lambs were assigned randomly to be necropsied. The lung,thymus,spleen and mesenteric lymph node were collected and stored at -80°C for RNA extraction. Total RNA was isolated from these tissues .we amplificated enJSRV and Hyal-2 fragment using RT-PCR and Labelled the specific probes using DIG , then analysised the expression of enJSRV envelope (env) and Hyal-2 mRNAs in the collected tissues through In Situ Hybridization. The results revealed that enJSRV envelope (env) and Hyal-2 mRNAs expressed in thymus, spleen, mesenteric lymph node and lung of different periods, but there were no positive signals in negative control. At the same time, the expression level of each target mRNA was analyzed by Real-Time reverse transcription PCR, and the results showed that based on the fold changes relative to the lung of 70d fetus, the enJSRV mRNA was most abundant by 26-fold in the spleen of 130d fetus and 22-fold in the thymus of 3d newborn. The expression level of enJSRV mRNA in the thymus and mesenteric lymph node of 130d fetal lambs was approximately 10-fold. It is clear that the level of enJSRV mRNA was much higher in immune organs than that in lungs. In addition that, the level of enJSRV mRNA was lower in all the tissues of 70d fetus than in other periods. While There was no significant difference among the expression levels of Hyal-2 mRNA in all collected tissues. This study will unravel the pathogenesis that sheep are tolerized towards infection by the exJSRV.