The molecular characterization and RNAi silencing of SjZFP1 in XXXX .

@entity2043 @entity19 @entity535 @entity219 @entity2042
UNASSIGNED: During development, @entity2042 undergoes many morphological and physiological transformations as a result of profound changes in gene expression. Proteins containing @entity219 finger motifs usually play an important role in DNA recognition, RNA packaging, and transcriptional activation. In our current study, we cloned the open reading frame (ORF) of SjZFP1 of @entity2043 , which encodes a @entity219 finger protein. We analyzed the complementary DNA (cDNA) sequence of SjZFP1 and examined the expression of SjZFP1 messenger RNA (mRNA) at various developmental stages. We also tested the effects of RNA interference (RNAi) silencing on worm burden, spawning, and egg hatching. The ORF in the SjZFP1 cDNA was 1017  bp in length and was predicted to encode a 338-aa protein with a molecular mass of approximately 38.5  kDa and theoretical isoelectric point (pI) of 7.08. Several conserved regions, including a B-box-type @entity219 -binding domain, two bipartite nuclear localization signal domains, a paired amphipathic helix repeat, and overlapping RING and PHD finger domains, were identified in the predicted @entity535 sequence of SjZFP1. Using real-time PCR, we showed that the SjZFP1 mRNA was expressed across all of the developmental stages of the parasite and that the level of transcription was highest in the cercariae, eggs, schistosomula, and mature adult worms. The level of SjZFP1 mRNA expression in cultured schistosomula treated with one of two SjZFP1-specific small interfering RNAs (siRNAs; AY770 and AY546) was reduced by over 80  %, compared with that in the controls. In RNAi experiments in BALB/c @entity19 , the level of SjZFP1 mRNA increased significantly when the @entity19 were treated with the same SjZFP1-specific siRNAs during the early stages of infection. By contrast, the level of SjZFP1 mRNA decreased significantly when the @entity19 were treated with the SjZFP1-specific siRNAs during the middle to late stages of infection. In four independent experiments, fewer worms were recovered from @entity19 treated with the SjZFP1-specific siRNAs, compared with the number of worms recovered from the control @entity19 . Both the average number and hatching rates of liver eggs recovered from @entity19 treated with the SjZFP1-specific siRNAs during the middle to late stages of infection were significantly lower than those of the liver eggs recovered from the control @entity19 . Our results suggest that the SjZFP1 gene might be important for parasite development, spawning in the vertebrate host, and egg hatching.
