ABSTRACT
Schistosoma japonicum adults are pre-embedded in a double-layer agar and made the block, then dehydrated with alcohol, isobutyl alcohol and n-butyl alcohol. Various staining procedures can be conducted after conventional sectioning and dewaxing. Complete longitudinal serial sections of the pre-embedded worms can be obtained, and the desired sections can be easily located accurately.
Subject(s)
Paraffin Embedding/methods , Schistosoma japonicum/anatomy & histology , Animals , Staining and LabelingABSTRACT
OBJECTIVE: To detect Toxoplasma gondii DNA by loop-mediated isothermal amplification (LAMP). METHODS: DNA was extracted by phenol-chloroform extraction from T. gondii tachyzoites. Four primers which recognized 6 distinct regions on the B1 gene of T. gondii were designed and used for LAMP assay. To evaluate the specificity of the method, Plasmodium vivax, P. falciparum, Pneumocystis carinii, Schistosoma japonicum, and mouse leucocytes were used gs controls. The parasite extract (T. gondii) was 10-fold serially diluted for evaluating the sensitivity of LAMP, and was amplified by LAMP. LAMP results were read with naked eye and analyzed by electrophoresis. RESULTS: After LAMP reaction, positive amplification was observed with T. gondii, but no positive signal was noted for the negative controls in the study. The sensitivity of LAMP assay reached up to 2-3 T. gondii tachyzoites/ml per reaction. CONCLUSION: LAMP assay shows proper specificity and sensitivity for the detection of T. gondii.
Subject(s)
DNA, Protozoan/isolation & purification , Nucleic Acid Amplification Techniques/methods , Toxoplasma/isolation & purification , Animals , DNA Primers , Mice , Sensitivity and Specificity , Toxoplasma/geneticsABSTRACT
Sj20.8 gene was amplified by PCR and inserted into eukaryotic expression plasmid pcDNA3.1 to construct recombinant plasmid pcDNA3.1/Sj20.8, which was then injected into the quadriceps femoris of the BALB/c mice. Results showed that the Sj20.8 antigen was low expressed in the local tissue of the mice, and was not able to significantly reduce eggs in the liver than in the control mice.
Subject(s)
Helminth Proteins/genetics , Schistosoma japonicum/immunology , Schistosomiasis japonica/immunology , Vaccines, DNA/immunology , Animals , DNA, Recombinant/immunology , Female , Gene Library , Immunization , Liver/drug effects , Liver/parasitology , Mice , Mice, Inbred BALB C , Parasite Egg Count , Plasmids/genetics , Random Allocation , Schistosoma japonicum/genetics , Schistosomiasis japonica/parasitology , Schistosomiasis japonica/prevention & control , Vaccines, DNA/administration & dosage , Vaccines, DNA/geneticsABSTRACT
OBJECTIVE: To acquire and analyze adult stage Schistosoma japonicum (Chinese strain) expressed sequence tags and new genes from an adult S. japonicum cDNA library, and to search new vaccine candidates and drug targets. METHODS: A cDNA library was constructed from adult stage S. japonicum. Clones were selected randomly from the cDNA library and were sequenced. ESTs and new genes were acquired after analysis in GenBank databases by BLAST and other programs. All ESTs and new genes were submitted to GenBank and received accession numbers. RESULTS: 149 ESTs were acquired from a total 382 clones that were randomly selected from the adult S. japonicum cDNA library. All ESTs were successfully submitted to the dbEST at Genbank. Some of them were homologous with sequences of male, female, egg, schistosomula, cercaria and miracidia of S. japonicum. 18 new genes of adult S. japonicum were acquired. Some genes were housekeeping genes and some genes might be interesting as vaccine candidates or drugs targets. CONCLUSIONS: The EST strategy is a rapid, efficient and economical method to acquire ESTs and to discover new genes of adult stage S. japonicum from cDNA libraries.
Subject(s)
Expressed Sequence Tags , Genes, Helminth , Schistosoma japonicum/genetics , Animals , Cloning, Molecular , DNA, Complementary/chemistry , Gene LibraryABSTRACT
OBJECTIVE: To amplify and sequence the partial gene coding for mucin-like protein from Chinese isolates of Schistosoma japonicum (SjMLP). METHODS: The antigenic determinants of SmMLP were predicted by PCGENE software and specific oligonucleotide primers were designed and synthesized. Total RNA was isolated from adult worms of S. japonicum using Trizol reagent and the coding region gene of SjMLP was amplified by RT-PCR technique. RESULTS: The coding region of SjMLP gene was specifically amplified by RT-PCR and the size of amplified fragment was 756 base pairs. The DNA sequence analysis result indicated that the coding sequence of the MLP was highly homologous between S. mansoni and S. japonicum. CONCLUSION: The amplified fragment is consistent to the predicted one, providing a basis for cloning and further study on DNA immunization.
Subject(s)
Antigens, Helminth/genetics , Mucins/genetics , Schistosoma japonicum/genetics , Amino Acid Sequence , Animals , Base Sequence , Cloning, Molecular , Mice , Molecular Sequence Data , Nucleic Acid Amplification Techniques , Proteins/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNA , Vaccines, DNA/geneticsABSTRACT
OBJECTIVE: To construct a recombinant prokaryotic expression vector (plasmid) containing microneme protein 1 (MIC1) partial gene in toxoplasma gondii (T. gondii) ZS2 isolate. The gene was expressed in varied Escherichia coli (E. coli) after sequencing. METHODS: The gene fragment coding MIC 1 from the genomic DNA of T. gondii ZS2 isolate was amplified by polymerase chain reaction (PCR). The gene was inserted to a prokaryotic expression vector pWR450-1 by digesting with restriction enzymes and linking reaction. The positive clone was screened on LB plates containing ampicillin and identified by restrictive enzyme digestion, PCR amplification and sequence analysis. The recombinant plasmid was transferred into E. coli TG1, JM109 (DE3) and DH5 alpha, and was expressed under the induction of IPTG. The expression products were identified by SDS-PAGE. The MIC1 gene structure was analyzed and compared in homology with the gene sequence of RH isolate using computer software. RESULTS: The recombinant plasmid pWR450-1/MIC1, after cloning from acquired 471 bp MIC1 gene fragment and amplified from the genome gene ZS2, was complete homologous to the sequence of RH isolate, reflecting its highly conservative. The gene could be expressed as fusion protein with 70,000 in varied E. coli. CONCLUSION: Recombinant plasmid pWR450-MIC1 was successfully constructed and could be expressed in different strains of E. coli, laying a foundation for research on its structure and function.
