The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Vera Lucia De Menezes Lima - One of the best experts on this subject based on the ideXlab platform.

  • potassium usnate toxicity against embryonic stages of the snail biomphalaria glabrata and schistosoma mansoni cercariae
    Acta Tropica, 2018
    Co-Authors: Hallysson Douglas Andrade De Araujo, Williams Nascimento De Siqueira, Nicacio Henrique Da Silva, Ana Maria Mendonca De Albuquerque Melo, Monica Cristina Barroso Martins, Andre De Lima Aires, Monica Camelo Pessoa De Azevedo Albuquerque, Vera Lucia De Menezes Lima
    Abstract:

    Abstract The snail Biomphalaria glabrata is the most important vector for Schistosoma mansoni. Control of this vector to prevent the spread of schistosomiasis is currently performed with the application of a niclosamide molluscicide, which is highly toxic to the environment. Screening of substances that show embryotoxic molluscicidal potential as well as have detrimental effects on cercariae is very relevant for the control of schistosomiasis, as the efficacy of prevention of the disease is increased if it acts as a molluscicide as well as on the cercariae of S. mansoni. The aim of this work was to evaluate the effect of potassium usnate derived from usnic acid on different stages of embryonic development of B. glabrata and on S. mansoni cercariae. After 24 h of exposure, potassium usnate showed embryotoxic activity across all embryonic stages. The values obtained from the LC50 for the embryonic stages were the following: blastula 5.22 μg/mL, gastrula 3.21 μg/mL, trochophore 3.58 μg/mL, veliger 2.79, and hippo stage 2.52 μg/mL. Against S. mansoni cercariae, it had LC90 and 100% mortality at concentrations of 2.5 and 5 μg/mL in 2 h of exposure. In conclusion, this is the first report of potassium usnate toxicity on the embryonic stages of B. glabrata and cercariae of S. mansoni, and this study shows the potassium usnate as a promising agent for the control of mansoni schistosomiasis.

  • toxicity of usnic acid from cladonia substellata lichen to embryos and adults of biomphalaria glabrata
    Acta Tropica, 2018
    Co-Authors: Hallysson Douglas Andrade De Araujo, Luanna Ribeiro Santos Silva, Williams Nascimento De Siqueira, Caique Silveira Martins Da Fonseca, Nicacio Henrique Da Silva, Ana Maria Mendonca De Albuquerque Melo, Monica Cristina Barroso Martins, Vera Lucia De Menezes Lima
    Abstract:

    Abstract This study reports the molluscicidal activity of usnic acid isolated from Cladonia substellata Vanio (lichen) on embryos at various stages of development and in adult mollusks of Biomphalaria glabrata. The toxicity of usnic acid was also evaluated through Artemia salina larvae mortality. Usnic acid was extracted with diethyl ether, isolated, purified, and its structure confirmed by analyzing the spectra of proton nuclear magnetic resonance. LC90 for 24 h of exposure were 1.62, 4.45, 5.36, and 4.49 μg mL−1 for blastula, gastrula, trocophore, and veliger embryonic stages, respectively, and 3.45 μg mL−1 for adult snails; LC50 of usnic acid against A. salina was 2.46 μg mL−1. LC90 assessed 7 days after exposure was 2.56 μg mL−1 for adult mollusks. In conclusion, these findings demonstrate that under laboratory conditions usnic acid has teratogenic and molluscicide potential to control the aquatic snail B. glabrata and may prove to be a promising candidate in the search for new molluscicide agents, but further detailed studies on its molluscicidal effect and possible environmental effects are needed.

Liping Duan - One of the best experts on this subject based on the ideXlab platform.

  • toxicity of a molluscicide candidate ppu07 against oncomelania hupensis gredler 1881 and local fish in field evaluation
    Chemosphere, 2019
    Co-Authors: Zhuo Chen, Weisi Wang, Hehua Hu, Shi-zhu Li, Xia Zhang, Huiyong Xu, Liping Duan
    Abstract:

    Abstract Schistosomiasis japonica caused by Schistosoma japonicum infection is recognized as a considerable economic and public health concern in Asia. Oncomelania hupensis is the sole intermediate host of S. japonicum. The only molluscicide recommended by World Health Organization (WHO) since 1960s is relative toxic to other aquatic species. In this article, we evaluated the novel molluscicide PPU07 in field trials on their efficiency against O. hupensis and toxicity for local fish. 25% PPU07 sulfate WP exhibited similar molluscicidal effect at 2.0 g/m2 and 2.0 g/m3 in the spraying and immersion trials with the WHO recommended molluscicide niclosamide (1 g/m2 and 1 g/m3). The mortality rates reached 95% and 96%, respectively. Moreover, little toxicity was observed for local fish and other aquatic organisms at the effective molluscicidal concentrations. In all, 25% PPU07 sulfate WP is a promising molluscicide for snail control, particularly in semi-commercial or commercial aquaculture ponds.

  • field evaluation of a novel molluscicide niclosamidate against oncomelania hupensis intermediate host of schistosoma japonicum
    Parasitology Research, 2017
    Co-Authors: Weisi Wang, Hehua Hu, Shi-zhu Li, Huaming Zhang, Xia Zhang, Liping Duan
    Abstract:

    The molluscicidal activity of a novel molluscicide (niclosamidate) was evaluated in field trials against Oncomelania hupensis, the intermediate host of Schistosoma japonicum. The environmental safety of niclosamidate for local fishes was also studied under field conditions. The results showed that, at the dosages of 8.0 g/m2 and 4.0 g/m3, niclosamidate exhibits highly potent molluscicidal activity in the spraying and immersion trials, resulting in mortality rates of up to 81.8 and 72.7%, respectively. Its performance seems to be target-specific, with good molluscicidal ability observed for Oncomelania hupensis snails, but very low toxicity for local fishes and other aquatic organisms. The results suggest that niclosamidate can be used as an alternative molluscicide for snail control, which would be particularly applicable in semi-commercial or commercial aquaculture ponds.

Huifen Dong - One of the best experts on this subject based on the ideXlab platform.

  • metabolic profiles of oncomelania hupensis after molluscicidal treatment carbohydrate metabolism targeted and energy deficiency
    Acta Tropica, 2020
    Co-Authors: Shi-zhu Li, Tao Xiong, Ni Jiang, Sha Xu, Yan Zhang, Xing Jian Xu, Huifen Dong, Qinping Zhao
    Abstract:

    Abstract Oncomelania hupensis is the intermediate host of Schistosoma japonicum, one of the Schistosoma species that can cause human schistosomiasis. Molluscicidal treatment remains the primary means to control snail. Niclosamide is the only molluscicide recommended by the World Health Organization, and it has been used throughout schistosomiasis-endemic areas in China for almost 30 years. In our previous studies on transcriptomics, morphology, and enzymology of snails after molluscicidal treatment, two effective molluscicides were used, 50% wettable powder of niclosamide ethanolamine salt (WPN) and a new molluscicide derived from niclosamide, the salt of quinoid-2′, 5-dichloro-4′-nitro-salicylanilide (LDS, simplified for Liu Dai Shui Yang An). Genes involved in cell structure mintenance, inhibition of neurohumoral transmission, and energy metabolism showed significant differential expression after molluscicide treatments. Damages in the structure of liver and muscle cells were accompanied by inhibited activities of enzymes related to carbohydrate metabolism and energy supply. This study was designed to clarify the dynamic metabolic process by metabonomics, together with the previous transcriptomic and enzymological profiles, to identify potential metabolite markers and metabolism pathways that related to the toxic mechanism of the molluscicide. In total, 56 metabolites were identified for O. hupensis, and 75% of these metabolites consisted of amino acids and derivatives, organic acids, and nucleic acid components. The concentration of glucose, maltose, succinate, choline, and alanine changed significantly after molluscicide treatments. These changes in metabolites mainly occurred in the process of carbohydrate metabolism, energy metabolism, and amino acid metabolism, primarily related to glycolysis/gluconeogenesis, oxidative phosphorylation, and transamination by KEGG pathway identification. Most of the identified pathways were also related to those differentially expressed unigenes and observed enzymes from our previous studies. Inhibited aerobic respiration and oxidative phosphorylation, and energy deficiency were implied further to be the leading causes of the final death of snails after molluscicide treatments. The hypothesised mathematical model in this study identified the rational hysteresis to explain the inconsistency of responses of unigenes, enzymes, and metabolites to molluscicide treatments. This study contributes to the comprehensive understanding of the molluscicidal mechanism in the metabolic process and this could assist in improving existing molluscicide formulations or development of new molluscicides.

  • morphological and enzymatical observations in oncomelania hupensis after molluscicide treatment implication for future molluscicide development
    Parasitology Research, 2016
    Co-Authors: Tao Xiong, Xing Jian Xu, Qinping Zhao, Ming Sen Jiang, Huifen Dong
    Abstract:

    A preparation of niclosamide named 50 % wettable powder of niclosamide ethanolamine salt (WPN), the only chemical molluscicide available in China, has been widely used for Oncomelania hupensis control over the past 20 years, but its molluscicidal mechanism has not been elucidated yet. Recently, a derivative of niclosamide, the salt of quinoid-2',5-dichloro-4'-nitro-salicylanilide (Liu Dai Shui Yang An, LDS), has been proven to have equivalent molluscicidal effects as WPN but with lower cost and significantly lower toxicity to fish than WPN. In our previous study, gene expression profiling of O. hupensis showed significantly effects after these two molluscicides had been applied. This study was designed to use morphological and enzymological analyses to further elucidate the mechanism by which these molluscicides cause snail death. After WPN or LDS treatment, the number of mitochondria of O. hupensis was reduced and their cristae appeared unclear, heterochromatin gathered to be polarized, ribosome numbers of the rough endoplasmic reticulums (rERs) decreased, myofilaments in muscle cells became disordered and loose, and cytoplasm in some liver cells was concentrated. Damage of cell structures and organelles suggested inhibited movement ability and effects on liver and energy metabolism following treatment. In parallel, activities of enzymes related with carbohydrate metabolism were inhibited except lactate dehydrogenase (LDH) increased in muscle tissue, and activities of enzymes related with stress response increased followed by decreasing to lower levels than those of the H2O-treated group. This shift of carbohydrate metabolism patterns led to insufficient energy supply and lactic acid accumulation, and variations of nitric oxide synthase (NOS), alanine aminotransferase (ALT), and superoxide dismutase (SOD) during process of molluscicide treatment suggested a stress response of snail to the molluscicides at early stages and later fatal damage in liver and nervous system. In general, effects of WPN and LDS were similar although LDS-treated snails showed more serious damage in the liver and a stronger inhibition of enzymes related with aerobic respiration and stress response. This was consistent with the transcriptome profile obtained previously. However, considering enzyme activities at post-transcriptional and protein levels, comprehensive identification and annotation of potential enzyme-related genes and regulation pattern would be necessary to provide great benefit for understanding of potential mechanism of these molluscicides and even for future molluscicide development.

  • de novo transcriptome analysis of oncomelania hupensis after molluscicide treatment by next generation sequencing implications for biology and future snail interventions
    PLOS ONE, 2015
    Co-Authors: Qinping Zhao, Tao Xiong, Xing Jian Xu, Ming Sen Jiang, Huifen Dong
    Abstract:

    The freshwater snail Oncomelania hupensis is the only intermediate host of Schistosoma japonicum, which causes schistosomiasis. This disease is endemic in the Far East, especially in mainland China. Because niclosamide is the only molluscicide recommended by the World Health Organization, 50% wettable powder of niclosamide ethanolamine salt (WPN), the only chemical molluscicide available in China, has been widely used as the main snail control method for over two decades. Recently, a novel molluscicide derived from niclosamide, the salt of quinoid-2',5-dichloro-4'-nitro-salicylanilide (Liu Dai Shui Yang An, LDS), has been developed and proven to have the same molluscicidal effect as WPN, with lower cost and significantly lower toxicity to fish than WPN. The mechanism by which these molluscicides cause snail death is not known. Here, we report the next-generation transcriptome sequencing of O. hupensis; 145,008,667 clean reads were generated and assembled into 254,286 unigenes. Using GO and KEGG databases, 14,860 unigenes were assigned GO annotations and 4,686 unigenes were mapped to 250 KEGG pathways. Many sequences involved in key processes associated with biological regulation and innate immunity have been identified. After the snails were exposed to LDS and WPN, 254 unigenes showed significant differential expression. These genes were shown to be involved in cell structure defects and the inhibition of neurohumoral transmission and energy metabolism, which may cause snail death. Gene expression patterns differed after exposure to LDS and WPN, and these differences must be elucidated by the identification and annotation of these unknown unigenes. We believe that this first large-scale transcriptome dataset for O. hupensis will provide an opportunity for the in-depth analysis of this biomedically important freshwater snail at the molecular level and accelerate studies of the O. hupensis genome. The data elucidating the molluscicidal mechanism will be of great benefit in future snail control efforts.

Tao Xiong - One of the best experts on this subject based on the ideXlab platform.

  • metabolic profiles of oncomelania hupensis after molluscicidal treatment carbohydrate metabolism targeted and energy deficiency
    Acta Tropica, 2020
    Co-Authors: Shi-zhu Li, Tao Xiong, Ni Jiang, Sha Xu, Yan Zhang, Xing Jian Xu, Huifen Dong, Qinping Zhao
    Abstract:

    Abstract Oncomelania hupensis is the intermediate host of Schistosoma japonicum, one of the Schistosoma species that can cause human schistosomiasis. Molluscicidal treatment remains the primary means to control snail. Niclosamide is the only molluscicide recommended by the World Health Organization, and it has been used throughout schistosomiasis-endemic areas in China for almost 30 years. In our previous studies on transcriptomics, morphology, and enzymology of snails after molluscicidal treatment, two effective molluscicides were used, 50% wettable powder of niclosamide ethanolamine salt (WPN) and a new molluscicide derived from niclosamide, the salt of quinoid-2′, 5-dichloro-4′-nitro-salicylanilide (LDS, simplified for Liu Dai Shui Yang An). Genes involved in cell structure mintenance, inhibition of neurohumoral transmission, and energy metabolism showed significant differential expression after molluscicide treatments. Damages in the structure of liver and muscle cells were accompanied by inhibited activities of enzymes related to carbohydrate metabolism and energy supply. This study was designed to clarify the dynamic metabolic process by metabonomics, together with the previous transcriptomic and enzymological profiles, to identify potential metabolite markers and metabolism pathways that related to the toxic mechanism of the molluscicide. In total, 56 metabolites were identified for O. hupensis, and 75% of these metabolites consisted of amino acids and derivatives, organic acids, and nucleic acid components. The concentration of glucose, maltose, succinate, choline, and alanine changed significantly after molluscicide treatments. These changes in metabolites mainly occurred in the process of carbohydrate metabolism, energy metabolism, and amino acid metabolism, primarily related to glycolysis/gluconeogenesis, oxidative phosphorylation, and transamination by KEGG pathway identification. Most of the identified pathways were also related to those differentially expressed unigenes and observed enzymes from our previous studies. Inhibited aerobic respiration and oxidative phosphorylation, and energy deficiency were implied further to be the leading causes of the final death of snails after molluscicide treatments. The hypothesised mathematical model in this study identified the rational hysteresis to explain the inconsistency of responses of unigenes, enzymes, and metabolites to molluscicide treatments. This study contributes to the comprehensive understanding of the molluscicidal mechanism in the metabolic process and this could assist in improving existing molluscicide formulations or development of new molluscicides.

  • morphological and enzymatical observations in oncomelania hupensis after molluscicide treatment implication for future molluscicide development
    Parasitology Research, 2016
    Co-Authors: Tao Xiong, Xing Jian Xu, Qinping Zhao, Ming Sen Jiang, Huifen Dong
    Abstract:

    A preparation of niclosamide named 50 % wettable powder of niclosamide ethanolamine salt (WPN), the only chemical molluscicide available in China, has been widely used for Oncomelania hupensis control over the past 20 years, but its molluscicidal mechanism has not been elucidated yet. Recently, a derivative of niclosamide, the salt of quinoid-2',5-dichloro-4'-nitro-salicylanilide (Liu Dai Shui Yang An, LDS), has been proven to have equivalent molluscicidal effects as WPN but with lower cost and significantly lower toxicity to fish than WPN. In our previous study, gene expression profiling of O. hupensis showed significantly effects after these two molluscicides had been applied. This study was designed to use morphological and enzymological analyses to further elucidate the mechanism by which these molluscicides cause snail death. After WPN or LDS treatment, the number of mitochondria of O. hupensis was reduced and their cristae appeared unclear, heterochromatin gathered to be polarized, ribosome numbers of the rough endoplasmic reticulums (rERs) decreased, myofilaments in muscle cells became disordered and loose, and cytoplasm in some liver cells was concentrated. Damage of cell structures and organelles suggested inhibited movement ability and effects on liver and energy metabolism following treatment. In parallel, activities of enzymes related with carbohydrate metabolism were inhibited except lactate dehydrogenase (LDH) increased in muscle tissue, and activities of enzymes related with stress response increased followed by decreasing to lower levels than those of the H2O-treated group. This shift of carbohydrate metabolism patterns led to insufficient energy supply and lactic acid accumulation, and variations of nitric oxide synthase (NOS), alanine aminotransferase (ALT), and superoxide dismutase (SOD) during process of molluscicide treatment suggested a stress response of snail to the molluscicides at early stages and later fatal damage in liver and nervous system. In general, effects of WPN and LDS were similar although LDS-treated snails showed more serious damage in the liver and a stronger inhibition of enzymes related with aerobic respiration and stress response. This was consistent with the transcriptome profile obtained previously. However, considering enzyme activities at post-transcriptional and protein levels, comprehensive identification and annotation of potential enzyme-related genes and regulation pattern would be necessary to provide great benefit for understanding of potential mechanism of these molluscicides and even for future molluscicide development.

  • de novo transcriptome analysis of oncomelania hupensis after molluscicide treatment by next generation sequencing implications for biology and future snail interventions
    PLOS ONE, 2015
    Co-Authors: Qinping Zhao, Tao Xiong, Xing Jian Xu, Ming Sen Jiang, Huifen Dong
    Abstract:

    The freshwater snail Oncomelania hupensis is the only intermediate host of Schistosoma japonicum, which causes schistosomiasis. This disease is endemic in the Far East, especially in mainland China. Because niclosamide is the only molluscicide recommended by the World Health Organization, 50% wettable powder of niclosamide ethanolamine salt (WPN), the only chemical molluscicide available in China, has been widely used as the main snail control method for over two decades. Recently, a novel molluscicide derived from niclosamide, the salt of quinoid-2',5-dichloro-4'-nitro-salicylanilide (Liu Dai Shui Yang An, LDS), has been developed and proven to have the same molluscicidal effect as WPN, with lower cost and significantly lower toxicity to fish than WPN. The mechanism by which these molluscicides cause snail death is not known. Here, we report the next-generation transcriptome sequencing of O. hupensis; 145,008,667 clean reads were generated and assembled into 254,286 unigenes. Using GO and KEGG databases, 14,860 unigenes were assigned GO annotations and 4,686 unigenes were mapped to 250 KEGG pathways. Many sequences involved in key processes associated with biological regulation and innate immunity have been identified. After the snails were exposed to LDS and WPN, 254 unigenes showed significant differential expression. These genes were shown to be involved in cell structure defects and the inhibition of neurohumoral transmission and energy metabolism, which may cause snail death. Gene expression patterns differed after exposure to LDS and WPN, and these differences must be elucidated by the identification and annotation of these unknown unigenes. We believe that this first large-scale transcriptome dataset for O. hupensis will provide an opportunity for the in-depth analysis of this biomedically important freshwater snail at the molecular level and accelerate studies of the O. hupensis genome. The data elucidating the molluscicidal mechanism will be of great benefit in future snail control efforts.

Qinping Zhao - One of the best experts on this subject based on the ideXlab platform.

  • metabolic profiles of oncomelania hupensis after molluscicidal treatment carbohydrate metabolism targeted and energy deficiency
    Acta Tropica, 2020
    Co-Authors: Shi-zhu Li, Tao Xiong, Ni Jiang, Sha Xu, Yan Zhang, Xing Jian Xu, Huifen Dong, Qinping Zhao
    Abstract:

    Abstract Oncomelania hupensis is the intermediate host of Schistosoma japonicum, one of the Schistosoma species that can cause human schistosomiasis. Molluscicidal treatment remains the primary means to control snail. Niclosamide is the only molluscicide recommended by the World Health Organization, and it has been used throughout schistosomiasis-endemic areas in China for almost 30 years. In our previous studies on transcriptomics, morphology, and enzymology of snails after molluscicidal treatment, two effective molluscicides were used, 50% wettable powder of niclosamide ethanolamine salt (WPN) and a new molluscicide derived from niclosamide, the salt of quinoid-2′, 5-dichloro-4′-nitro-salicylanilide (LDS, simplified for Liu Dai Shui Yang An). Genes involved in cell structure mintenance, inhibition of neurohumoral transmission, and energy metabolism showed significant differential expression after molluscicide treatments. Damages in the structure of liver and muscle cells were accompanied by inhibited activities of enzymes related to carbohydrate metabolism and energy supply. This study was designed to clarify the dynamic metabolic process by metabonomics, together with the previous transcriptomic and enzymological profiles, to identify potential metabolite markers and metabolism pathways that related to the toxic mechanism of the molluscicide. In total, 56 metabolites were identified for O. hupensis, and 75% of these metabolites consisted of amino acids and derivatives, organic acids, and nucleic acid components. The concentration of glucose, maltose, succinate, choline, and alanine changed significantly after molluscicide treatments. These changes in metabolites mainly occurred in the process of carbohydrate metabolism, energy metabolism, and amino acid metabolism, primarily related to glycolysis/gluconeogenesis, oxidative phosphorylation, and transamination by KEGG pathway identification. Most of the identified pathways were also related to those differentially expressed unigenes and observed enzymes from our previous studies. Inhibited aerobic respiration and oxidative phosphorylation, and energy deficiency were implied further to be the leading causes of the final death of snails after molluscicide treatments. The hypothesised mathematical model in this study identified the rational hysteresis to explain the inconsistency of responses of unigenes, enzymes, and metabolites to molluscicide treatments. This study contributes to the comprehensive understanding of the molluscicidal mechanism in the metabolic process and this could assist in improving existing molluscicide formulations or development of new molluscicides.

  • morphological and enzymatical observations in oncomelania hupensis after molluscicide treatment implication for future molluscicide development
    Parasitology Research, 2016
    Co-Authors: Tao Xiong, Xing Jian Xu, Qinping Zhao, Ming Sen Jiang, Huifen Dong
    Abstract:

    A preparation of niclosamide named 50 % wettable powder of niclosamide ethanolamine salt (WPN), the only chemical molluscicide available in China, has been widely used for Oncomelania hupensis control over the past 20 years, but its molluscicidal mechanism has not been elucidated yet. Recently, a derivative of niclosamide, the salt of quinoid-2',5-dichloro-4'-nitro-salicylanilide (Liu Dai Shui Yang An, LDS), has been proven to have equivalent molluscicidal effects as WPN but with lower cost and significantly lower toxicity to fish than WPN. In our previous study, gene expression profiling of O. hupensis showed significantly effects after these two molluscicides had been applied. This study was designed to use morphological and enzymological analyses to further elucidate the mechanism by which these molluscicides cause snail death. After WPN or LDS treatment, the number of mitochondria of O. hupensis was reduced and their cristae appeared unclear, heterochromatin gathered to be polarized, ribosome numbers of the rough endoplasmic reticulums (rERs) decreased, myofilaments in muscle cells became disordered and loose, and cytoplasm in some liver cells was concentrated. Damage of cell structures and organelles suggested inhibited movement ability and effects on liver and energy metabolism following treatment. In parallel, activities of enzymes related with carbohydrate metabolism were inhibited except lactate dehydrogenase (LDH) increased in muscle tissue, and activities of enzymes related with stress response increased followed by decreasing to lower levels than those of the H2O-treated group. This shift of carbohydrate metabolism patterns led to insufficient energy supply and lactic acid accumulation, and variations of nitric oxide synthase (NOS), alanine aminotransferase (ALT), and superoxide dismutase (SOD) during process of molluscicide treatment suggested a stress response of snail to the molluscicides at early stages and later fatal damage in liver and nervous system. In general, effects of WPN and LDS were similar although LDS-treated snails showed more serious damage in the liver and a stronger inhibition of enzymes related with aerobic respiration and stress response. This was consistent with the transcriptome profile obtained previously. However, considering enzyme activities at post-transcriptional and protein levels, comprehensive identification and annotation of potential enzyme-related genes and regulation pattern would be necessary to provide great benefit for understanding of potential mechanism of these molluscicides and even for future molluscicide development.

  • de novo transcriptome analysis of oncomelania hupensis after molluscicide treatment by next generation sequencing implications for biology and future snail interventions
    PLOS ONE, 2015
    Co-Authors: Qinping Zhao, Tao Xiong, Xing Jian Xu, Ming Sen Jiang, Huifen Dong
    Abstract:

    The freshwater snail Oncomelania hupensis is the only intermediate host of Schistosoma japonicum, which causes schistosomiasis. This disease is endemic in the Far East, especially in mainland China. Because niclosamide is the only molluscicide recommended by the World Health Organization, 50% wettable powder of niclosamide ethanolamine salt (WPN), the only chemical molluscicide available in China, has been widely used as the main snail control method for over two decades. Recently, a novel molluscicide derived from niclosamide, the salt of quinoid-2',5-dichloro-4'-nitro-salicylanilide (Liu Dai Shui Yang An, LDS), has been developed and proven to have the same molluscicidal effect as WPN, with lower cost and significantly lower toxicity to fish than WPN. The mechanism by which these molluscicides cause snail death is not known. Here, we report the next-generation transcriptome sequencing of O. hupensis; 145,008,667 clean reads were generated and assembled into 254,286 unigenes. Using GO and KEGG databases, 14,860 unigenes were assigned GO annotations and 4,686 unigenes were mapped to 250 KEGG pathways. Many sequences involved in key processes associated with biological regulation and innate immunity have been identified. After the snails were exposed to LDS and WPN, 254 unigenes showed significant differential expression. These genes were shown to be involved in cell structure defects and the inhibition of neurohumoral transmission and energy metabolism, which may cause snail death. Gene expression patterns differed after exposure to LDS and WPN, and these differences must be elucidated by the identification and annotation of these unknown unigenes. We believe that this first large-scale transcriptome dataset for O. hupensis will provide an opportunity for the in-depth analysis of this biomedically important freshwater snail at the molecular level and accelerate studies of the O. hupensis genome. The data elucidating the molluscicidal mechanism will be of great benefit in future snail control efforts.