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Parasitology International Sep 2007The difference in the distribution of Schistosoma eggs in the viscera has not been clearly elucidated in the two closely related species Schistosoma japonicum and...
The difference in the distribution of Schistosoma eggs in the viscera has not been clearly elucidated in the two closely related species Schistosoma japonicum and Schistosoma mekongi. In this study, we quantitatively compared the distribution of eggs in mice infected with the two species. In S. mekongi-infected mice, 56.6% to 69.4% of total eggs were found in the distal small intestine 9 to 15 weeks after infection, while in S. japonicum-infected mice, 48.8% to 71.8% of eggs were found in the proximal small intestine during the same period. There were significantly more eggs in the liver in mice infected with S. japonicum than in those infected with S. mekongi. The number of adult worms recovered did not differ between the two species during the study period. The total number of eggs laid in the tissues also did not differ between the two species at 12 to 15 weeks postinfection, but in the earlier period the total number of eggs was significantly fewer in S. mekongi-infected than in S. japonicum-infected mice, suggesting the delayed maturation of the former compared with the latter. These results clearly show that S. japonicum and S. mekongi exhibit different oviposition behavior in their hosts.
Topics: Animals; Host-Parasite Interactions; Intestines; Liver; Mice; Mice, Inbred ICR; Oviposition; Ovum; Parasite Egg Count; Schistosoma; Schistosoma japonicum; Schistosomiasis; Schistosomiasis japonica; Species Specificity; Viscera
PubMed: 17521955
DOI: 10.1016/j.parint.2007.03.004 -
PLoS Neglected Tropical Diseases Jul 2017Microsatellites have been found to be useful in determining genetic diversities of various medically-important parasites which can be used as basis for an effective...
BACKGROUND
Microsatellites have been found to be useful in determining genetic diversities of various medically-important parasites which can be used as basis for an effective disease management and control program. In Asia and Africa, the identification of different geographical strains of Schistosoma japonicum, S. haematobium and S. mansoni as determined through microsatellites could pave the way for a better understanding of the transmission epidemiology of the parasite. Thus, the present study aims to apply microsatellite markers in analyzing the populations of S. japonicum from different endemic areas in the Philippines for possible strain differentiation.
METHODOLOGY/ PRINCIPAL FINDINGS
Experimental mice were infected using the cercariae of S. japonicum collected from infected Oncomelania hupensis quadrasi snails in seven endemic municipalities. Adult worms were harvested from infected mice after 45 days of infection and their DNA analyzed against ten previously characterized microsatellite loci. High genetic diversity was observed in areas with high endemicity. The degree of genetic differentiation of the parasite population between endemic areas varies. Geographical separation was considered as one of the factors accounting for the observed difference between populations. Two subgroups have been observed in one of the study sites, suggesting that co-infection with several genotypes of the parasite might be present in the population. Clustering analysis showed no particular spatial structuring between parasite populations from different endemic areas. This result could possibly suggest varying degrees of effects of the ongoing control programs and the existing gene flow in the populations, which might be attributed to migration and active movement of infected hosts from one endemic area to another.
CONCLUSIONS/ SIGNIFICANCE
Based on the results of the study, it is reasonable to conclude that genetic diversity could be one possible criterion to assess the infection status in highly endemic areas. Genetic surveillance using microsatellites is therefore important to predict the ongoing gene flow and degree of genetic diversity, which indirectly reflects the success of the control program in schistosomiasis-endemic areas.
Topics: Animals; Cercaria; Coinfection; Female; Genetic Variation; Genotype; Geography; Humans; Male; Mice; Mice, Inbred BALB C; Microsatellite Repeats; Philippines; Schistosoma japonicum; Schistosomiasis japonica; Snails
PubMed: 28692692
DOI: 10.1371/journal.pntd.0005749 -
Journal of Visualized Experiments : JoVE May 2018Extracellular vesicles (EVs) are membranous vesicles released by a variety of cells into the extracellular microenvironment. EVs represent a population of heterogeneous...
Extracellular vesicles (EVs) are membranous vesicles released by a variety of cells into the extracellular microenvironment. EVs represent a population of heterogeneous vesicles, whose size range between 40 and 1,000 nm. Accumulated evidence indicated that EVs play important regulatory roles in pathogen-host interactions. A deep understanding of schistosome EVs should provide insights into the mechanisms underlying schistosome-host interactions, enabling development of novel strategies against schistosomiasis. Here, we aim to further study EVs functions in schistosomes by presenting a protocol for the isolation and characterization of EVs from adult Schistosoma japonicum (S. japonicum). EVs were isolated from in vitro culture medium using centrifugation combined with a commercial exosome isolation kit. The isolated S. japonicum EVs (SjEVs) typically possess a diameter of 100 - 400 nm, and are characterized by transmission electronic microscopy and western blotting. The usage of PKH67 dye-labeled SjEVs has demonstrated that SjEVs are internalized by the recipient cells. Overall, our protocol provides an alternative method for isolating EVs from adult schistosomes; the isolated SjEVs may be suitable for functional analysis.
Topics: Animals; Extracellular Vesicles; Schistosoma japonicum
PubMed: 29889194
DOI: 10.3791/57514 -
Veterinary Research Sep 2020Eggs produced by bisexual infected mature female worms (MF) of Schistosoma japonicum are important in the transmission of the parasite and responsible for the...
Eggs produced by bisexual infected mature female worms (MF) of Schistosoma japonicum are important in the transmission of the parasite and responsible for the pathogenesis of schistosomiasis. The single-sex infected female worms (SF) cannot mature and do not produce normal eggs; also they do not induce severe damage to the host. In this study, the microRNA (miRNA) expression profiles of 25d MF and 25d SF were investigated through Solexa deep-sequencing technology to explore the developmental mechanisms of schistosome female worms. There were 36 differentially expressed miRNA, 20 up-regulated and 16 down-regulated found in MF/SF worms, including some development related miRNA such as bantam (ban), let-7, miR-124, miR-8, miR-1, miR-7. There were 166 target genes of up-regulated miRNA and 201 target genes of down-regulated miRNA after comparing the target gene prediction software results with RNA-Seq transcriptome results. Analysis of the target genes shows that different ones are involved in MF and SF worms in Gene Ontology terms, with a similar situation in KEGG. This observation indicates that different genes regulated by differentially expressed miRNA take part in MF and SF and lead to differential sexual status. This means that the sexual status of female worms is regulated by miRNA.
Topics: Animals; Female; Gene Expression; Gene Expression Regulation; MicroRNAs; RNA, Helminth; Schistosoma japonicum
PubMed: 32977838
DOI: 10.1186/s13567-020-00851-4 -
Molecular and Biochemical Parasitology Mar 2009Three peroxiredoxins (Prxs) are expressed during most of the developmental stages in the schistosome. Prx-1 is localized on the surface of the schistosomula and adults...
Three peroxiredoxins (Prxs) are expressed during most of the developmental stages in the schistosome. Prx-1 is localized on the surface of the schistosomula and adults of Schistosoma japonicum, while Prx-2 is localized in the sub-tegumental tissues, parenchyma, vitelline glands, and gut epithelium, but not on the surface of the worms. We applied RNA interference techniques to suppress the specific genes of S. japonicum Prxs. Schistosomula of S. japonicum were cultured together with long-dsRNA encoding Prx-1 and Prx-2 of S. japonicum (the soaking method). The transcription level of each Prx gene was reduced by an RNA interference (RNAi)-mediated effect specifically. Although neither Prx was the essential protein for survival of S. japonicum schistosomula, Prx-1 dsRNA-treated larvae were susceptible to hydrogen peroxide. Moreover, these larvae were also susceptible to t-butyl hydroperoxide and cumene-hydroperoxide. However, the knockdown of neither Prx-1 nor Prx-2 influenced the resistance against nitric oxide generated from DETA/NO. Prx-1 may work as a scavenger against reactive oxygen species (ROS) generated outside of the schistosomes to prevent the oxidation of the bodies and/or the attack by immune cells producing the ROS. These findings suggest that Prx-1 may become a novel target of drugs and vaccines for schistosomiasis.
Topics: Animals; Benzene Derivatives; Free Radical Scavengers; Gene Expression Regulation; Hydrogen Peroxide; Nitric Oxide; Parasitic Sensitivity Tests; Peroxiredoxins; RNA Interference; RNA, Double-Stranded; Schistosoma japonicum; Survival Analysis; tert-Butylhydroperoxide
PubMed: 19041905
DOI: 10.1016/j.molbiopara.2008.11.002 -
Parasites & Vectors May 2019Yellow cattle and water buffalo are important natural reservoir hosts and the main transmission sources of Schistosoma japonicum in endemic areas of China. The worms... (Comparative Study)
Comparative Study
BACKGROUND
Yellow cattle and water buffalo are important natural reservoir hosts and the main transmission sources of Schistosoma japonicum in endemic areas of China. The worms from the two hosts have marked differences in general worm morphology and ultrastructure, gene transcription and protein expression profiles.
RESULTS
To investigate microRNAs (miRNAs) involved in the regulation of schistosome development and survival, we compared miRNA expression profiles of adult schistosomes derived from yellow cattle and water buffalo by using high-throughput sequencing with Illumina Hiseq Xten. Schistosoma japonicum from water buffalo and yellow cattle yielded 63.78 million and 63.21 million reads, respectively, of which nearly 50% and 49% could be mapped to selected miRNAs in miRbase. A total of 206 miRNAs were identified, namely 79 previously annotated miRNAs of S. japonicum and 127 miRNAs that matched with the S. japonicum genome and were highly similar to the annotated miRNAs from other organisms. Among the 79 miRNAs, five (sja-miR-124-3p, sja-miR-219-5p, sja-miR-2e-3p, sja-miR-7-3p and sja-miR-3490) were significantly upregulated in the schistosomes from water buffalo compared with those from yellow cattle. A total of 268 potential target genes were predicted for these five differentially expressed miRNAs. Eleven differentially expressed targets were confirmed by qRT-PCR among 15 tested targets, one of which was further validated through dual-luciferase reporter assay. Among the 127 'possible' S. japonicum miRNAs, ten were significantly differentially expressed in the schistosomes from these two hosts.
CONCLUSIONS
These results highlight the important roles of miRNAs in regulating the development and survival of schistosomes in water buffalo and yellow cattle and facilitate understanding of the miRNA regulatory mechanisms in schistosomes derived from different susceptible hosts.
Topics: Animals; Buffaloes; Cattle; Cattle Diseases; Female; Gene Expression Profiling; Male; MicroRNAs; RNA, Helminth; Schistosoma japonicum; Schistosomiasis japonica
PubMed: 31046821
DOI: 10.1186/s13071-019-3450-7 -
Parasitology Research Feb 2017Schistosomiasis is caused by the genus Schistosoma and affected more than 250 million people worldwide. Schistosoma japonicum was once seriously endemic in China and...
Schistosomiasis is caused by the genus Schistosoma and affected more than 250 million people worldwide. Schistosoma japonicum was once seriously endemic in China and nearly 60 years of efforts has seen great success in disease control. However, due to its zoonotic nature and complex life cycle, the schistosomiasis transmission control and final elimination would require, besides an intersectoral approach, deep understanding of population genetics of the parasite. We therefore performed a snail survey in two marshland villages of Anhui province of China and collected S. japonicum cercariae from infected snails. By using the recent developed microsatellite panel comprising seven loci, we genotyped the sampled parasites and analyzed the population genetic diversity and structure. The results showed much lower infection prevalence of S. japonicum in snails and low infected snail density in either marshland village. Through population genetic analyses, a considerable genetic diversity of parasites was revealed, whereas a small number of clusters were inferred and the sign of bottleneck effect was detected in each village. For the first time in S. japonicum in two villages, we provided estimates of effective population sizes with two different approaches. The results indicated that the parasite in two villages could eventually be eradicated with the ongoing integral control measures, but with potential risk of reinvasion of immigrant parasites through the Yangtze River. Such would be of great importance in assessment of the effects of ongoing control measures and prediction of the transmission capability for S. japonicum, thus guiding decisions on the choice of further control work.
Topics: Animals; China; Genetic Variation; Genotype; Humans; Microsatellite Repeats; Rivers; Rural Population; Schistosoma japonicum; Schistosomiasis japonica; Snails
PubMed: 27838835
DOI: 10.1007/s00436-016-5321-x -
Scientific Reports Apr 2016Schistosomiasis is a major parasitic disease caused by blood flukes of the genus Schistosoma. Several million people all over the world are estimated to suffer from...
Schistosomiasis is a major parasitic disease caused by blood flukes of the genus Schistosoma. Several million people all over the world are estimated to suffer from severe morbidity as a consequence of schistosomiasis. The worm's eggs, which cause the symptoms of schistosomiasis, are generally used to diagnose the disease. In this study, we employed egg-based systematic evolution of ligands by exponential enrichment (egg-SELEX) and identified a panel of ssDNA aptamers specifically binding to eggs derived from S. japonicum. Among these, two aptamers LC6 and LC15 exhibited strong binding to and specific recognition of S. japonicum eggs, but not eggs from Fasciolopsis buski, Enterobius, Ascaris or Clonorchis sinensis. Furthermore, tissue imaging results revealed that LC15 could recognize S. japonicum eggs laid in liver tissues with a detection ratio of 80.5%. Collectively, therefore, we obtained useful aptamers specifically recognizing S. japonicum eggs, which will facilitate the development of an effective tool for both schistosomiasis diagnosis and drug delivery.
Topics: Animals; Antigens, Helminth; Aptamers, Nucleotide; Mass Screening; SELEX Aptamer Technique; Schistosoma japonicum; Sensitivity and Specificity; Zygote
PubMed: 27121794
DOI: 10.1038/srep24986 -
Parasitology Research Jul 2015The Vasa gene is a vital germline marker to study the origin and development of germ cells and gonads in many organisms. Until now, little information was available...
The Vasa gene is a vital germline marker to study the origin and development of germ cells and gonads in many organisms. Until now, little information was available about the characteristics of the Vasa gene in Schistosoma japonicum (S. japonicum). In this study, we cloned the open reading frame (ORF) of the S. japonicum Vasa-like gene (Sj-Vasa). The expression pattern and tissue localization of Sj-Vasa were also analyzed. Our results showed that Sj-Vasa shared the general feature of DEAD-box family member proteins. Sj-Vasa was transcribed and expressed throughout the S. japonicum life cycle with transcription exhibiting high levels at day 24 in both male and female worms, and the expression level in the female was always higher than that in the male. Sj-Vasa protein was localized in a variety of tissues of adult schistosomes, including the gonads (ovary, vitellarium, and testes), the subtegument, and some cells of the parenchyma. To our knowledge, this is the first report of preliminary characterization and expression of the Vasa-like gene that may play an important role in the development of the worm, especially in reproductive organs of S. japonicum.
Topics: Animals; Female; Gene Expression Regulation, Developmental; Helminth Proteins; Humans; Male; Ovary; Schistosoma japonicum; Schistosomiasis japonica; Testis
PubMed: 25899325
DOI: 10.1007/s00436-015-4473-4 -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... Apr 2020To characterize the epidermal growth factor receptor () gene in ( gene) and investigate the role of the gene in regulating the growth, reproductive system, maturation...
OBJECTIVE
To characterize the epidermal growth factor receptor () gene in ( gene) and investigate the role of the gene in regulating the growth, reproductive system, maturation and fecundity of .
METHODS
Rapid amplification of cDNA ends (RACE) was performed to obtain the full length of the gene, and the gene expression was quantified in different developmental stages of using a quantitative real-time PCR (qPCR) assay. The tissue localization of the gene was detected in 22-day parasite using whole-mount hybridization (WISH). Following RNA interference (RNAi)-induced knockdown of the gene, the worm length, pairing rate and worm burden of . were measured, and the worm morphology was observed using optical microscopy and confocal microscopy.
RESULTS
The gene was identified with a conserved tyrosine-kinase active site, and the gene expression was detected at various developmental stages in male and female parasites. WISH showed that the transcript of the gene was localized on the tegument and in the digestive organs of . RNAi-induced knockdown resulted in marked suppression of the worm growth, smaller size of male testicles that contained more immature spermatocytes, and apparent impairment of ovary and vitelline gland development. In addition, no eggs were found in the uterus of knocked-down female parasites, indicating the interruption of egg production.
CONCLUSIONS
Inhibition of expression may remarkably suppress the growth and maturation of , and interrupt the egg production.
Topics: Animals; DNA, Complementary; ErbB Receptors; Female; Genes, erbB-1; Male; RNA Interference; Schistosoma japonicum; Schistosomiasis japonica
PubMed: 32458600
DOI: 10.16250/j.32.1374.2019300