Objective:To explore the effect of AIBL on Oncomelania hupensis,the intermediate snail host of Schistosoma japonicum.Methods:The enzyme histochemical profiles of cholineslerase, cytochrome oxidase,lactate dehydrogenas...Objective:To explore the effect of AIBL on Oncomelania hupensis,the intermediate snail host of Schistosoma japonicum.Methods:The enzyme histochemical profiles of cholineslerase, cytochrome oxidase,lactate dehydrogenase,nitric oxide synthase,and succinate dehydrogenase in the soft tissues of Oncomelania hupensis,the intermediate host snail of Schistosoma japonicum, were analyzed before and after treatment with the active ingredient of Buddleia lindleyana(AIBL), a potent and safe plant molluscicide.Results:Treatment with AIBL induced a notable decrease in the activities of the five enzymes(P【0.01).Conclusions:The results indicate that AIBL impairs the activities of the enzymes,thereby influencing the transfer of neurotransmitter and energy supply in Oncomelania hupensis and ultimately harming their various physiological functions, which are considered to cause death of the species.展开更多
Schistosomiasis is a parasitic disease mostly found in areas along the Changjiang River of China. The disease is spread solely through an intermediary named oncomelania, so its spread of schistosomiasis can be control...Schistosomiasis is a parasitic disease mostly found in areas along the Changjiang River of China. The disease is spread solely through an intermediary named oncomelania, so its spread of schistosomiasis can be controlled by properly designing water intakes which prevent oncomelania from entering farming land or residential areas. This paper reports a successful design process and a new oncomelania free intake device. The design of the new intake is based on a sound research program in which extensive experimental studies were carried out to gain knowledge of oncomelania eco hydraulic behavior and detailed flow field information through CFD simulation.展开更多
This paper has analyzed allelopathic effects ofNerium indicum on Oncomelania hupensis through triterpene sapogenins, a potential molluscicide. The snails were treated under six various concentrations （0, 20, 40, 60, ...This paper has analyzed allelopathic effects ofNerium indicum on Oncomelania hupensis through triterpene sapogenins, a potential molluscicide. The snails were treated under six various concentrations （0, 20, 40, 60, 80, 100 mg/L） of triterpene sapogenins and five periods （1, 2, 3, 4, 5 days）. The mortality of snails was positively correlated with the concentration of triterpene sapogenins and exposure time. The results ofprobit analysis showed that the LD50 （Lethal Dose, 50%） oftriterpenoid saponins from N. indicum by immersion for 2, 3, 4, 5 days were 78.31, 30.26, 20.50, 14.19 mg/L, respectively. And the corresponding 95% confidence intervals were 63.60-108.19, 9.49-44.42, 2.86-30.90, 0.23-22.79 mg/L, respectively. The observations of both scanning electron microscope and transmission electron microscope proved that 40 mg/L triterpene sapogenins could cause apparent damage to the structure of soft tissue, liver and intestine of O. hupensis. The esterase （EST） isozyme electrophoresis in liver of O. hupensis treated by 40 mg/L of the concentrations lixivium of the triterpene sapogenins from N. indicum was analyzed for 24, 48, 72, 96, 120 h, respectively. The activity of enzyme was higher than control water group after been treated up to 24-48 h, and then lowered and disappeared after 72 h. It was implicated that the extracted triterpene sapogenin from N. indicum were promising for controlling the snail, which were also providing the foundation for constructing plant community of oleander to control O. hupensis.展开更多
Background Schistosoma japonicum is a parasitic flatworm that causes human schistosomiasis, which is a significant cause of morbidity in China, the Philippines and Indonesia.Oncomelania hupensis (Gastropoda: Pomatiops...Background Schistosoma japonicum is a parasitic flatworm that causes human schistosomiasis, which is a significant cause of morbidity in China, the Philippines and Indonesia.Oncomelania hupensis (Gastropoda: Pomatiopsidae) is the unique intermediate host ofS. japonicum. A complete genome sequence ofO. hupensis will enable the fundamental understanding of snail biology as well as its co-evolution with theS. japonicum parasite. Assembling a high-quality reference genome ofO. hupehensis will provide data for further research on the snail biology and controlling the spread ofS. japonicum.Methods The draft genome was de novo assembly using the long-read sequencing technology (PacBio Sequel II) and corrected with Illumina sequencing data. Then, using Hi-C sequencing data, the genome was assembled at the chromosomal level. CAFE was used to do analysis of contraction and expansion of the gene family and CodeML module in PAML was used for positive selection analysis in protein coding sequences.Results A total length of 1.46 Gb high-qualityO. hupensis genome with 17 unique full-length chromosomes (2n = 34) of the individual including a contig N50 of 1.35 Mb and a scaffold N50 of 75.08 Mb. Additionally, 95.03% of these contig sequences were anchored in 17 chromosomes. After scanning the assembled genome, a total of 30,604 protein-coding genes were predicted. Among them, 86.67% were functionally annotated. Further phylogenetic analysis revealed thatO. hupensis was separated from a common ancestor ofPomacea canaliculata andBellamya purificata approximately 170 million years ago. Comparing the genome ofO. hupensis with its most recent common ancestor, it showed 266 significantly expanded and 58 significantly contracted gene families (P < 0.05). Functional enrichment of the expanded gene families indicated that they were mainly involved with intracellular, DNA-mediated transposition, DNA integration and transposase activity.Conclusions Integrated use of multiple sequencing technologies, we have successfully constructed the genome at the chromosomal-level ofO. hupensis. These data will not only provide the compressive genomic information, but also benefit future work on population genetics of this snail as well as evolutional studies betweenS. japonicum and the snail host.展开更多
To study the toxicity of extracts of Ginkgo biloba sarcotesta to Oncomelania hupensis,snails were exposed to 40% and 80% of 24 h LC 50 of the extract of Ginkgo bilba for 24 h,choline esterase(ChE),alanine aminotransfe...To study the toxicity of extracts of Ginkgo biloba sarcotesta to Oncomelania hupensis,snails were exposed to 40% and 80% of 24 h LC 50 of the extract of Ginkgo bilba for 24 h,choline esterase(ChE),alanine aminotransferase(ALT),alkaline phosphatase(ALP),lactate dehydrogenase(LDH),succino dehydrogenase(SDH),malic dehydrogenase(MDH)activities in cephalopodium and liver were determined by enzyme kinetic assay.Arecoline and niclosamide were used as reference molluscicides.The results showed that sarcotesta of Ginkgo biloba could inhibit ChE,ALT,ALP and MDH activities both in cephalopodium and liver;arecoline could inhibit ChE,ALP,SDH and MDH activities in cephalopodium and ChE,ALT,ALP,SDH and MDH activities in liver.Niclosamide had inhibitory effects upon ChE,ALT,ALP,SDH and MDH activities in cephalopodium,and ChE,ALT,ALP and SDH activities in liver.All three molluscicides did not inhibite LDH activity in cephalopodium and liver.These results indicate that lethal effects of extracts of sarcotesta of Ginkgo biloba are mediated via inhibition of MDH activitiy,and interference with the NADH respiratory chains.Inhibition of vital enzymic mechanisms causes snails to death.展开更多
文摘Objective:To explore the effect of AIBL on Oncomelania hupensis,the intermediate snail host of Schistosoma japonicum.Methods:The enzyme histochemical profiles of cholineslerase, cytochrome oxidase,lactate dehydrogenase,nitric oxide synthase,and succinate dehydrogenase in the soft tissues of Oncomelania hupensis,the intermediate host snail of Schistosoma japonicum, were analyzed before and after treatment with the active ingredient of Buddleia lindleyana(AIBL), a potent and safe plant molluscicide.Results:Treatment with AIBL induced a notable decrease in the activities of the five enzymes(P【0.01).Conclusions:The results indicate that AIBL impairs the activities of the enzymes,thereby influencing the transfer of neurotransmitter and energy supply in Oncomelania hupensis and ultimately harming their various physiological functions, which are considered to cause death of the species.
文摘Schistosomiasis is a parasitic disease mostly found in areas along the Changjiang River of China. The disease is spread solely through an intermediary named oncomelania, so its spread of schistosomiasis can be controlled by properly designing water intakes which prevent oncomelania from entering farming land or residential areas. This paper reports a successful design process and a new oncomelania free intake device. The design of the new intake is based on a sound research program in which extensive experimental studies were carried out to gain knowledge of oncomelania eco hydraulic behavior and detailed flow field information through CFD simulation.
基金Acknowledgments The authors would like to thank the National Natural Science Foundation of China （grant No. 30471506, 30570322, 39670654, 30671818） and the Science and Technology Foundation of Forest （No. 2006BAD03AI 5） for providing funds to the research.
文摘This paper has analyzed allelopathic effects ofNerium indicum on Oncomelania hupensis through triterpene sapogenins, a potential molluscicide. The snails were treated under six various concentrations （0, 20, 40, 60, 80, 100 mg/L） of triterpene sapogenins and five periods （1, 2, 3, 4, 5 days）. The mortality of snails was positively correlated with the concentration of triterpene sapogenins and exposure time. The results ofprobit analysis showed that the LD50 （Lethal Dose, 50%） oftriterpenoid saponins from N. indicum by immersion for 2, 3, 4, 5 days were 78.31, 30.26, 20.50, 14.19 mg/L, respectively. And the corresponding 95% confidence intervals were 63.60-108.19, 9.49-44.42, 2.86-30.90, 0.23-22.79 mg/L, respectively. The observations of both scanning electron microscope and transmission electron microscope proved that 40 mg/L triterpene sapogenins could cause apparent damage to the structure of soft tissue, liver and intestine of O. hupensis. The esterase （EST） isozyme electrophoresis in liver of O. hupensis treated by 40 mg/L of the concentrations lixivium of the triterpene sapogenins from N. indicum was analyzed for 24, 48, 72, 96, 120 h, respectively. The activity of enzyme was higher than control water group after been treated up to 24-48 h, and then lowered and disappeared after 72 h. It was implicated that the extracted triterpene sapogenin from N. indicum were promising for controlling the snail, which were also providing the foundation for constructing plant community of oleander to control O. hupensis.
基金supported by National Key Research and Development Program of China(No.2021YFC2300800,2021YFC2300803).
文摘Background Schistosoma japonicum is a parasitic flatworm that causes human schistosomiasis, which is a significant cause of morbidity in China, the Philippines and Indonesia.Oncomelania hupensis (Gastropoda: Pomatiopsidae) is the unique intermediate host ofS. japonicum. A complete genome sequence ofO. hupensis will enable the fundamental understanding of snail biology as well as its co-evolution with theS. japonicum parasite. Assembling a high-quality reference genome ofO. hupehensis will provide data for further research on the snail biology and controlling the spread ofS. japonicum.Methods The draft genome was de novo assembly using the long-read sequencing technology (PacBio Sequel II) and corrected with Illumina sequencing data. Then, using Hi-C sequencing data, the genome was assembled at the chromosomal level. CAFE was used to do analysis of contraction and expansion of the gene family and CodeML module in PAML was used for positive selection analysis in protein coding sequences.Results A total length of 1.46 Gb high-qualityO. hupensis genome with 17 unique full-length chromosomes (2n = 34) of the individual including a contig N50 of 1.35 Mb and a scaffold N50 of 75.08 Mb. Additionally, 95.03% of these contig sequences were anchored in 17 chromosomes. After scanning the assembled genome, a total of 30,604 protein-coding genes were predicted. Among them, 86.67% were functionally annotated. Further phylogenetic analysis revealed thatO. hupensis was separated from a common ancestor ofPomacea canaliculata andBellamya purificata approximately 170 million years ago. Comparing the genome ofO. hupensis with its most recent common ancestor, it showed 266 significantly expanded and 58 significantly contracted gene families (P < 0.05). Functional enrichment of the expanded gene families indicated that they were mainly involved with intracellular, DNA-mediated transposition, DNA integration and transposase activity.Conclusions Integrated use of multiple sequencing technologies, we have successfully constructed the genome at the chromosomal-level ofO. hupensis. These data will not only provide the compressive genomic information, but also benefit future work on population genetics of this snail as well as evolutional studies betweenS. japonicum and the snail host.
文摘To study the toxicity of extracts of Ginkgo biloba sarcotesta to Oncomelania hupensis,snails were exposed to 40% and 80% of 24 h LC 50 of the extract of Ginkgo bilba for 24 h,choline esterase(ChE),alanine aminotransferase(ALT),alkaline phosphatase(ALP),lactate dehydrogenase(LDH),succino dehydrogenase(SDH),malic dehydrogenase(MDH)activities in cephalopodium and liver were determined by enzyme kinetic assay.Arecoline and niclosamide were used as reference molluscicides.The results showed that sarcotesta of Ginkgo biloba could inhibit ChE,ALT,ALP and MDH activities both in cephalopodium and liver;arecoline could inhibit ChE,ALP,SDH and MDH activities in cephalopodium and ChE,ALT,ALP,SDH and MDH activities in liver.Niclosamide had inhibitory effects upon ChE,ALT,ALP,SDH and MDH activities in cephalopodium,and ChE,ALT,ALP and SDH activities in liver.All three molluscicides did not inhibite LDH activity in cephalopodium and liver.These results indicate that lethal effects of extracts of sarcotesta of Ginkgo biloba are mediated via inhibition of MDH activitiy,and interference with the NADH respiratory chains.Inhibition of vital enzymic mechanisms causes snails to death.
