RESUMO
@#Different miRNAs are involved in the life cycles of Schistosoma japonicum. The aim of this study was to examine the expression profile of miRNAs in individual S. japonicum of different sex before and after pairing (18 and 24 dpi). The majority of differential expressed miRNAs were highly abundant at 14 dpi, except for sja-miR-125b and sja-miR-3505, in both male and female. Moreover, it was estimated that sja-miR-125b and sja-miR-3505 might be related to laying eggs. sja-miR-2a-5p and sja-miR-3484-5p were expressed at 14 dpi in males and were significantly clustered in DNA topoisomerase III, Rap guanine nucleotide exchange factor 1 and L-serine/L-threonine ammonia-lyase. Target genes of sja-miR-2d-5p, sja-miR-31- 5p and sja-miR-125a, which were expressed at 14 dpi in males but particularly females, were clustered in kelch-like protein 12, fructose-bisphosphate aldolase, class I, and heat shock protein 90 kDa beta. Predicted target genes of sja-miR-3483-3p (expressed at 28 dpi in females but not in males) were clustered in 26S proteasome regulatory subunit N1, ATPdependent RNA helicase DDX17. Predicted target genes of sja-miR-219-5p, which were differentially expressed at 28 dpi in females but particularly males, were clustered in DNA excision repair protein ERCC-6, protein phosphatase 1D, and ATPase family AAA domaincontaining protein 3A/B. Moreover, at 28 dpi, eight miRNAs were significantly up-regulated in females compared to males. The predicted target genes of these miRNAs were significantly clustered in heat shock protein 90 kDa beta, 26S proteasome regulatory subunit N1, and protein arginine N-methyltransferase 1. To sum up, differentially expressed miRNAs may have an essential role and provide necessary information on clarifying this trematode’s growth, development, maturation, and infection ability to mammalian hosts in its complex life cycle, and may be helpful for developing new drug targets and vaccine candidates for schistosomiasis.
RESUMO
Oncomelania snails are the intermediate hoste of Schistosoma japonicum in Asian countries. In order to understand the genetic and morphological variation of Oncomelania snails in mainland China, field snails from 31 localities were collected and investigated by means of allele enzyme electrophoresis and numerical taxonomical technics. Results demonstrated that out of 17 loci examined, seven polymorphic loci were presented. Genetic distance (Nei, 1978) among the populations varied from 0.03 to 0.27. The phenogenetic tree based on UPGMA cluster analysis showed that genetic diversity corresponded to geographic distribution along the Yangtze River, which provided supplementary genetic data about the evolution of Oncomelania spp. A morphological study showed that Mahalanobis' morphological distance ranged from 1.53 to 346.7. Both genetic and morphological data indicated that the diversity among populations of smooth shelled snails was higher than that among populations of ribbed shelled snails. A positive correlation (r = 0.80) between Mahalanobis' morphological distance and genetic distance supports the hypothesis that the different shell phenotypes represent different species or subspecies.