Identification and characterization of microRNAs in the pancreatic fluke Eurytrema pancreaticum.
BACKGROUND
Eurytrema pancreaticum is one of the most common flukes, which mainly infects ruminants globally and infects human beings accidentally; causing eurytremiasis that has high veterinary and economic importance. MicroRNAs (miRNAs) are small non-coding RNAs and are now considered as a key mechanism of gene regulation at the post-transcription level.


METHODS
We investigated the global miRNA expression profile of E. pancreaticum adults using next-generation sequencing technology combined with real-time quantitative PCR.


RESULTS
By using the genome of the closely-related species Schistosoma japonicum as reference, we obtained 27 miRNA candidates out of 16.45 million raw sequencing reads, with 13 of them found as known miRNAs in S. japonicum and/or S. mansoni, and the remaining 14 miRNAs were considered as novel. Five out of the 13 known miRNAs coming from one family named as sja-miR-2, including family members from miR-2a to miR-2e. Targets of 19 miRNAs were successfully predicated out of the 17401 mRNA and EST non-redundant sequences of S. japonicum. It was found that a significant high number of targets were related to "chch domain-containing protein mitochondrial precursor" (n = 29), "small subunit ribosomal protein s30e" (n = 21), and "insulin-induced gene 1 protein" (n = 9). Besides, "egg protein cp3842" (n = 2), "fumarate hydratase" (n = 2), "ubiquitin-conjugating enzyme" (n = 2), and "sperm-associated antigen 6" (n = 1) were also found as targets of the miRNAs of E. pancreaticum.


CONCLUSIONS
The present study represents the first global characterization of E. pancreaticum miRNAs, which provides novel resources for a better understanding of the parasite, which, in turn, has implications for the effective control of the disease it causes.
State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China.
Min-Jun
MJ
Xu
Chun-Ren
CR
Wang
Si-Yang
SY
Huang
Jing-Hua
JH
Fu
Dong-Hui
DH
Zhou
Qiao-Cheng
QC
Chang
Xu
X
Zheng
Xing-Quan
XQ
Zhu
D000818:Animals; D004012:Dicrocoeliidae / Q000235:genetics*; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D059014:High-Throughput Nucleotide Sequencing; D035683:MicroRNAs / Q000235:genetics*; D018510:RNA, Helminth / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction
D035683:MicroRNAs; D018510:RNA, Helminth