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Shengping L Hwang - One of the best experts on this subject based on the ideXlab platform.
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myosin heavy chain expression in cranial pectoral fin and Tail Muscle regions of zebrafish embryos
Molecular Reproduction and Development, 2002Co-Authors: Mouyun Peng, Lijane Shih, Shengping L HwangAbstract:To investigate whether different myosin heavy chain (MHC) isoforms may constitute myofibrils in the trunk and Tail musculature and if their respective expression may be regulated by spadeTail (spt) and no Tail (brachyury), we identified and characterized mRNA expression patterns of an embryonic- and Tail Muscle-specific MHC gene (named myhz2) during zebrafish development in wild type, spt, and ntl mutant embryos. The identified myhz2MHC gene encodes a polypeptide containing 1,935 amino acids. Deduced amino acid comparisons showed that myhz2 MHC shared 92.6% sequence identity with that of carp fast skeletal MHC. Temporal and spatial myhz2 MHC mRNA expression patterns were analyzed by quantitative RT-PCR and whole-mount in situ hybridization using primer pairs and probes designed from the 3′-untranslated region (UTR). Temporally myhz2 MHC mRNA appears in pharyngula embryos and peaks in protruding-mouth larvae. The expression level decreased in 7-day-old hatching larvae, and mRNA expression was not detectable in adult fish. Spatially in pharyngula embryos, mRNA was localized only in the Tail somite region, while in long-pec embryos, transcripts were also expressed in the two cranial Muscle elements of the adductor mandibulae and medial rectus, as well as in pectoral fin Muscles and the Tail Muscle region. Myhz2 MHC mRNA was expressed in most cranial Muscle elements, pectoral fin Muscles, and the Tail Muscle region of 3-day-old hatching larvae. In contrast, no expression of myhz2 MHC mRNA could be observed in spt prim-15 mutant embryos. In spt long-pec mutant embryos, transcripts were expressed in two cranial Muscle elements and the Tail Muscle region, but not in pectoral fin Muscles, while only trace amounts of myhz2 MHC mRNA were expressed in the remaining Tail Muscle region of 38 hpf and long-pec ntl mutant embryos. Mol. Reprod. Dev. 63: 422–429, 2002. © 2002 Wiley-Liss, Inc.
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myosin heavy chain expression in cranial pectoral fin and Tail Muscle regions of zebrafish embryos
Molecular Reproduction and Development, 2002Co-Authors: Mouyun Peng, Lijane Shih, Huiju Wen, Chingming Kuo, Shengping L HwangAbstract:To investigate whether different myosin heavy chain (MHC) isoforms may constitute myofibrils in the trunk and Tail musculature and if their respective expression may be regulated by spadeTail (spt) and no Tail (brachyury), we identified and characterized mRNA expression patterns of an embryonic- and Tail Muscle-specific MHC gene (named myhz2) during zebrafish development in wild type, spt, and ntl mutant embryos. The identified myhz2 MHC gene encodes a polypeptide containing 1,935 amino acids. Deduced amino acid comparisons showed that myhz2 MHC shared 92.6% sequence identity with that of carp fast skeletal MHC. Temporal and spatial myhz2 MHC mRNA expression patterns were analyzed by quantitative RT-PCR and whole-mount in situ hybridization using primer pairs and probes designed from the 3'-untranslated region (UTR). Temporally myhz2 MHC mRNA appears in pharyngula embryos and peaks in protruding-mouth larvae. The expression level decreased in 7-day-old hatching larvae, and mRNA expression was not detectable in adult fish. Spatially in pharyngula embryos, mRNA was localized only in the Tail somite region, while in long-pec embryos, transcripts were also expressed in the two cranial Muscle elements of the adductor mandibulae and medial rectus, as well as in pectoral fin Muscles and the Tail Muscle region. Myhz2 MHC mRNA was expressed in most cranial Muscle elements, pectoral fin Muscles, and the Tail Muscle region of 3-day-old hatching larvae. In contrast, no expression of myhz2 MHC mRNA could be observed in spt prim-15 mutant embryos. In spt long-pec mutant embryos, transcripts were expressed in two cranial Muscle elements and the Tail Muscle region, but not in pectoral fin Muscles, while only trace amounts of myhz2 MHC mRNA were expressed in the remaining Tail Muscle region of 38 hpf and long-pec ntl mutant embryos.
Huan Zhong - One of the best experts on this subject based on the ideXlab platform.
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mechanistic understanding of low methylmercury bioaccessibility from crayfish procambarus clarkii Muscle tissue
Science of The Total Environment, 2017Co-Authors: Qian Peng, B K Greenfield, Fei Dang, Huan Zhong, Yu GongAbstract:Recent research indicates that dietary exposure to mercury and other metals from crayfish consumption poses a human health concern, particularly in regions with high crayfish-consuming populations. To better understand consumption risk from methylmercury (MeHg), we quantified MeHg bioaccessibility in edible Tail Muscle of cooked red swamp crayfish (Procambarus clarkii, collected from seven cities in China), versus cooked fillet tissue of two finfish species: yellow croaker (Larimichthys polyactis) and snakehead (Channa argus). Results indicated that digestive solubilization rate (DSR) of MeHg in crayfish (7.8±3.9% for restaurant-crayfish and 9.8±0.8% for market-crayfish) was lower than the rate in yellow croaker (25.8±2.7%) and snakehead (26.2±4.7%) tissue, suggesting that relatively low MeHg bioaccessibility in crayfish may reduce dietary exposure to humans. Three possible mechanisms for the reduced MeHg DSR in crayfish tissue were examined: MeHg-Se interactions, MeHg subcellular fractionation, and Hg-amino acid binding. Selenium concentrations were comparable among the examined species, and no significant relationship was observed between tissue Se and MeHg DSR. Similarly, observed differences in subcellular fractionation of MeHg could not explain the species-specific MeHg DSR. Therefore, MeHg-Se interactions and MeHg subcellular fractionation do not explain the relatively low MeHg bioaccessibility in crayfish. Significantly higher cysteine and arginine content was found in crayfish than in the finfish. We suspect that the lower MeHg bioaccessibility of crayfish Tail Muscle may be attributed to the higher cysteine concentrations, and thus, stronger MeHg-protein binding in crayfish. These results support the interpretation that bioaccessibility differences will alter risk interpretations for MeHg, especially when comparing hazard across aquatic food types.
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human exposure to methylmercury from crayfish procambarus clarkii in china
Environmental Geochemistry and Health, 2016Co-Authors: Qian Peng, B K Greenfield, Fei Dang, Huan ZhongAbstract:Methylmercury (MeHg) accumulation in aquatic food raises global concerns about human exposure to MeHg. Crayfish is the world’s third largest farmed crustacean species and a favorite aquatic food in many countries. However, human health hazard due to MeHg exposure via crayfish consumption is unclear, partly because appropriate survey data are lacking. We report on mercury concentrations and speciation in edible Tail Muscle of crayfish collected from restaurants in 23 Chinese cities. On average, MeHg constituted 99.1 % of mercury in Tail Muscle, and MeHg concentrations were comparable with those reported for fish in China. Variation in MeHg concentrations was not attributable to broad geographic region (i.e., provinces) or Tail length. For different populations, potential health risk (characterized by hazard quotient or HQ) of MeHg exposure through crayfish consumption depended largely on crayfish consumption rates. In particular, a health hazard (HQ > 1) was found for high-rate consumers (i.e., 95 %ile or higher) in some cities in the middle and lower reaches of the Yangtze River (MLYR), during the peak consumption season. Our results suggest that more attention should be paid to dietary MeHg intake via crayfish consumption in China, particularly for communities with high consumption in MLYR.
Trude Vrålstad - One of the best experts on this subject based on the ideXlab platform.
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Microcystins in European Noble Crayfish Astacus astacus in Lake Steinsfjorden, a Planktothrix-Dominated Lake.
Toxins, 2020Co-Authors: Ingunn A. Samdal, David A. Strand, Andreas Ballot, Johannes Rusch, Sigrid Haande, Kjersti E. Løvberg, Christopher O. Miles, Trude VrålstadAbstract:Lake Steinsfjorden, an important Norwegian location for noble crayfish (Astacus astacus), is often affected by cyanobacterial blooms caused by microcystin (MC)-producing Planktothrix spp. The impact of MCs on noble crayfish as a food source and crayfish health is largely unknown. We investigated the quantities and correlations of MCs in noble crayfish and lake water during and after a cyanobacterial bloom peaking in June-July 2015. Noble crayfish and water samples were collected monthly from June to October 2015 and in October 2016. The content of MCs was analysed by ELISA from Tail Muscle, intestine, stomach and hepatopancreas. PCR analysis for Planktothrix gene markers was performed on crayfish stomach content. Water samples were analysed for phytoplankton composition, biomass and MCs. PCR-positive stomach contents indicated Planktothrix to be part of the noble crayfish diet. Concentrations of MCs were highest in the hepatopancreas, stomach and intestine, peaking in August-September. Tail Muscle contained low concentrations of MCs. Similar levels of MCs were found in crayfish from 2016. Except in September 2015, a normal portion of boiled noble crayfish Tails was below the tolerable daily intake (TDI) for MCs for humans. Removing the intestine more than halved the content of MCs and seems a reasonable precautionary measure for noble crayfish consumers.
Mouyun Peng - One of the best experts on this subject based on the ideXlab platform.
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myosin heavy chain expression in cranial pectoral fin and Tail Muscle regions of zebrafish embryos
Molecular Reproduction and Development, 2002Co-Authors: Mouyun Peng, Lijane Shih, Shengping L HwangAbstract:To investigate whether different myosin heavy chain (MHC) isoforms may constitute myofibrils in the trunk and Tail musculature and if their respective expression may be regulated by spadeTail (spt) and no Tail (brachyury), we identified and characterized mRNA expression patterns of an embryonic- and Tail Muscle-specific MHC gene (named myhz2) during zebrafish development in wild type, spt, and ntl mutant embryos. The identified myhz2MHC gene encodes a polypeptide containing 1,935 amino acids. Deduced amino acid comparisons showed that myhz2 MHC shared 92.6% sequence identity with that of carp fast skeletal MHC. Temporal and spatial myhz2 MHC mRNA expression patterns were analyzed by quantitative RT-PCR and whole-mount in situ hybridization using primer pairs and probes designed from the 3′-untranslated region (UTR). Temporally myhz2 MHC mRNA appears in pharyngula embryos and peaks in protruding-mouth larvae. The expression level decreased in 7-day-old hatching larvae, and mRNA expression was not detectable in adult fish. Spatially in pharyngula embryos, mRNA was localized only in the Tail somite region, while in long-pec embryos, transcripts were also expressed in the two cranial Muscle elements of the adductor mandibulae and medial rectus, as well as in pectoral fin Muscles and the Tail Muscle region. Myhz2 MHC mRNA was expressed in most cranial Muscle elements, pectoral fin Muscles, and the Tail Muscle region of 3-day-old hatching larvae. In contrast, no expression of myhz2 MHC mRNA could be observed in spt prim-15 mutant embryos. In spt long-pec mutant embryos, transcripts were expressed in two cranial Muscle elements and the Tail Muscle region, but not in pectoral fin Muscles, while only trace amounts of myhz2 MHC mRNA were expressed in the remaining Tail Muscle region of 38 hpf and long-pec ntl mutant embryos. Mol. Reprod. Dev. 63: 422–429, 2002. © 2002 Wiley-Liss, Inc.
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myosin heavy chain expression in cranial pectoral fin and Tail Muscle regions of zebrafish embryos
Molecular Reproduction and Development, 2002Co-Authors: Mouyun Peng, Lijane Shih, Huiju Wen, Chingming Kuo, Shengping L HwangAbstract:To investigate whether different myosin heavy chain (MHC) isoforms may constitute myofibrils in the trunk and Tail musculature and if their respective expression may be regulated by spadeTail (spt) and no Tail (brachyury), we identified and characterized mRNA expression patterns of an embryonic- and Tail Muscle-specific MHC gene (named myhz2) during zebrafish development in wild type, spt, and ntl mutant embryos. The identified myhz2 MHC gene encodes a polypeptide containing 1,935 amino acids. Deduced amino acid comparisons showed that myhz2 MHC shared 92.6% sequence identity with that of carp fast skeletal MHC. Temporal and spatial myhz2 MHC mRNA expression patterns were analyzed by quantitative RT-PCR and whole-mount in situ hybridization using primer pairs and probes designed from the 3'-untranslated region (UTR). Temporally myhz2 MHC mRNA appears in pharyngula embryos and peaks in protruding-mouth larvae. The expression level decreased in 7-day-old hatching larvae, and mRNA expression was not detectable in adult fish. Spatially in pharyngula embryos, mRNA was localized only in the Tail somite region, while in long-pec embryos, transcripts were also expressed in the two cranial Muscle elements of the adductor mandibulae and medial rectus, as well as in pectoral fin Muscles and the Tail Muscle region. Myhz2 MHC mRNA was expressed in most cranial Muscle elements, pectoral fin Muscles, and the Tail Muscle region of 3-day-old hatching larvae. In contrast, no expression of myhz2 MHC mRNA could be observed in spt prim-15 mutant embryos. In spt long-pec mutant embryos, transcripts were expressed in two cranial Muscle elements and the Tail Muscle region, but not in pectoral fin Muscles, while only trace amounts of myhz2 MHC mRNA were expressed in the remaining Tail Muscle region of 38 hpf and long-pec ntl mutant embryos.
Laurent Coen - One of the best experts on this subject based on the ideXlab platform.
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In Vivo Transfection of Naked DNA into Xenopus Tadpole Tail Muscle
Cold Spring Harbor protocols, 2017Co-Authors: Lindsey Marshall, Fabrice Girardot, Barbara A. Demeneix, Laurent CoenAbstract:In vivo gene transfer systems are important to study foreign gene expression and promoter regulation in an organism, with the benefit of exploring this in an integrated environment. Direct injection of plasmids encoding exogenous promoters and genes into Muscle has numerous advantages: the protocol is easy, efficient, and shows time-persistent plasmid expression in transfected muscular cells. After injecting naked-DNA plasmids into tadpole Tail Muscle, transgene expression is strong, reproducible, and correlates with the amount of DNA injected. Moreover, expression is stable as long as the tadpoles remain, or are maintained, in premetamorphic stages. By directly expressing genes and regulated promoters in Xenopus tadpole Muscle in vivo, one can exploit the powerful experimental advantages of gene transfer systems in an intact, physiologically normal animal.
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Apoptosis of Tail Muscle during amphibian metamorphosis involves a caspase 9-dependent mechanism.
Developmental Dynamics, 2005Co-Authors: Isaline Rowe, Barbara A. Demeneix, K. Palmier, G. Levi, Karine Le Blay, David Du Pasquier, Laurent CoenAbstract:The climax of amphibian metamorphosis is marked by thyroid hormone-dependent tadpole Tail resorption, implicating apoptosis of multiple cell types, including epidermal cells, fibroblasts, nerve cells, and Muscles. The molecular cascades leading to and coordinating the death of different cell types are not fully elucidated. It is known that the mitochondrial pathway, and in particular the Bax and XR11 genes, regulates the balance between apoptosis and survival in Muscle. However, the down-stream factors modulated by changes in mitochondrial permeability have not been studied in a functional context. To investigate further the mitochondrial-dependent pathway, we analyzed the regulation and the role of caspase 9 in Xenopus tadpoles. We report that caspase 9 mRNA is expressed in the Tail before metamorphosis and increases before and during climax. Similarly, at the protein level, the production of active forms of caspase 9 increases in Muscle tissue as metamorphosis progresses. To assess the functional role of caspase 9, we designed a dominant-negative protein. Overexpression of this dominant-negative abrogates both Bax-induced cell death in vitro and Muscle apoptosis in vivo during natural metamorphosis. These findings consolidate a model of metamorphic Muscle death that directly implicates the mitochondrial pathway and the apoptosome.
