Comparative microRNA expression profiles of Schistosoma japonicum from SCID mouse and BALB/c mouse

Background: In immunodeficient mice, the growth and reproduction of schistosome were significantly retarded, and their virulence on the host was also weakened. Some studies have suggested that host factors including endocrine and immune signals can modulate the parasite's development and maturation. However, it is still not clear for the molecular mechanisms underlying the growth and maturation regulation of schistosome. Methods: We isolated the total RNAs of female and male schistosome from immunodeficient SCID mice and immunocompetent BALB/c mice (labeled as S_F, S_M, B_F and B_M) obtained at five weeks post infection with cercariae, and constructed cDNA libraries of small RNAs using small RNA sample pre kit for small RNA deep sequencing on an Illumina (Solexa) platform. Results: Of the 122 (75 known and 47 novel) identified S. japonicum-specific miRNAs, statistical analysis revealed that 33 miRNAs (17 miRNAs were up-regulated and 16 were down-regulated, P<0.05) in female schistosome and 33 miRNAs (13 miRNAs were up-regulated and 20 were down-regulated, P<0.05) in male schistosome from SCID mice were differentially expressed when compared with those from BALB/c mice. The Venn diagram of the differentially expressed miRNAs shows 21 miRNAs were common between S_F vs B_ F and S_M vs B_M, 12 miRNAs were specific in female comparison, and other 12 were specific in male comparison. Conclusions: This study provides a comparative microRNAs expression profiles of schistosomes derived from SCID mice and immunocompetent BALB/c mice. A number of microRNAs were identified to potentially participate in regulating the development of schistosomes. These findings lay the foundation for schistosomiasis research in regulation of the development of schistosomes and provide a valuable resource for screening antischistosomal intervention targets or vaccine candidates. Overall design: Examination of Schistosoma japonicum worms from SCID mouse and BALB/c mouse