[Molecular characteristics and RNA interference efficiency of Schistosoma japonicum Sj79 gene]

To study the structural features and characteristics of a novel gene Schistosoma japonicum 79 (Sj79), and observe its effect of RNA interference (RNAi) , so as to provide the experimental basis for its further function study and mechanism study of anti reproductive development of schistosome.

The gene structure and characteristics of Sj79 were analyzed by bioinformatics methods. Then the expressions of Sj79 messenger RNA (mRNA) during the different developmental stages of schistosome were analyzed and the effects of RNAi silencing were observed by the soaking method. The transcriptional levels of Sj79 after RNAi were detected by real time PCR.

The open reading frame of Sj79 contained 696 base pairs with an exon structure. The gene had obvious stage specificity, and its transcriptional level in mature female worms was the highest. After soaking for 3 d, the Sj79 mRNA level [ (41.0 ± 12.3)%] in the siRNA-1 group with low dosage (20 nmol/L) was lower than that in the siRNA-NC group [(103.2 ± 14.4)%], the difference was statistically significant (t = 3.28,P < 0.05). When with high dosage (200 nmol/L), both the Sj79 mRNA levels in the siRNA-1 group [(15.8 ± 10.9)%] and siRNA-2 group [(11.1 ± 8.8)%] were significantly lower than that in the siRNA-NC group [(100.1 ± 6.3)%] (t = 13.44, 27.84, both P < 0.01). After soaking for 7 d, only the Sj79 mRNA levels in the siRNA-1 group [(43.4 ± 4.5)%] and siRNA-2 group [(62.5 ± 5.4)%] with low dosage were lower than that in the siRNA-NC group [(100.4 ± 5.2)%], and the differences had statistical significance (t = 8.33, 5.07, both P < 0.01).

Through this study, we have improved the mRNA sequence and genomic information of Sj79 gene, and understood its structural features, as well as selected out two effect fragments siRNA-1 and siRNA-2, which will provide the basic evidences for the further study on egg laying interference of the female adult worm of schistosome in vitro.