The Experts below are selected from a list of 1320 Experts worldwide ranked by ideXlab platform
Rick A Relyea - One of the best experts on this subject based on the ideXlab platform.
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very highly toxic effects of endosulfan across nine species of tadpoles lag effects and family level sensitivity
Environmental Toxicology and Chemistry, 2009Co-Authors: Devin K Jones, John I Hammond, Rick A RelyeaAbstract:Pesticides are commonly used for health and economic benefits worldwide, but increased use has led to increased contamination of aquatic habitats. To understand potential impacts on nontarget organisms in these habitats, toxicologists generally use short-term (4-d) toxicity tests on model organisms. For most pesticides, few amphibian tests have been conducted, but there is growing concern about the potential impact of pesticides to amphibian populations. For the insecticide endosulfan, previous studies have found that low concentrations can be very highly toxic to amphibians and have suggested that this mortality may exhibit important lag effects. To estimate the lethal concentration of endosulfan that would cause 50% mortality after 4 d (LC504-d) across a diversity of amphibians and the presence of lag effects, LC504-d experiments were conducted on nine species of tadpoles from three families (Bufonidae: Bufo americanus, B. boreas; Hylidae: Pseudacris crucifer, P. regilla, Hyla versicolor, and Ranidae: Rana pipiens, R. clamitans, R. cascadae, R. catesbeiana) and then held the animals for an additional 4 d in clean water. The LC504-d values for endosulfan ranged from 1.3 to 120 ppb, which classifies endosulfan as highly toxic to very highly toxic. Moreover, holding the animals for an additional 4 d in clean water revealed significant additional mortality in three of the nine species. Leopard frogs, for example, experienced no significant death during the initial 4-d exposure to 60 ppb but 97% death after an additional 4 d in clean water. A phylogenetic pattern also appears to exist among families, with Bufonidae being least susceptible, Hylidae being moderately susceptible, and Ranidae being most susceptible. Results from the present study provide valuable data to assess the impact of endosulfan on a globally declining group of vertebrates.
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VERY HIGHLY TOXIC EFFECTS OF ENDOSULFAN ACROSS NINE SPECIES OF TADPOLES: LAG EFFECTS AND FAMILY-LEVEL SENSITIVITY
2009Co-Authors: Devin K Jones, John I Hammond, Rick A RelyeaAbstract:Abstract—Pesticides are commonly used for health and economic benefits worldwide, but increased use has led to increased contamination of aquatic habitats. To understand potential impacts on nontarget organisms in these habitats, toxicologists generally use short-term (4-d) toxicity tests on model organisms. For most pesticides, few amphibian tests have been conducted, but there is growing concern about the potential impact of pesticides to amphibian populations. For the insecticide endosulfan, previous studies have found that low concentrations can be very highly toxic to amphibians and have suggested that this mortality may exhibit important lag effects. To estimate the lethal concentration of endosulfan that would cause 50 % mortality after 4 d (LC504-d) across a diversity of amphibians and the presence of lag effects, LC504-d experiments were conducted on nine species of tadpoles from three families (Bufonidae: Bufo americanus, B. boreas; Hylidae: Pseudacris crucifer, P. regilla, Hyla versicolor; and Ranidae: Rana pipiens, R. clamitans, R. cascadae, R. catesbeiana) and then held the animals for an additional 4 d in clean water. The LC504-d values for endosulfan ranged from 1.3 to 120 ppb, which classifies endosulfan as highly toxic to very highly toxic. Moreover, holding the animals for an additional 4 d in clean water revealed significant additional mortality in three of the nine species. Leopard frogs, for example, experienced no significant death during the initial 4-d exposure to 60 ppb but 97 % death after an additional 4 d in clean water. A phylogenetic pattern also appears to exist among families, with Bufonidae being least susceptible, Hylidae being moderately susceptible, and Ranidae being most susceptible. Results from the present study provide valuable data to assess the impact of endosulfan on a globally declining group of vertebrates. Keywords—Ecotoxicology Amphibian decline Nontarget Anuran Contaminan
Devin K Jones - One of the best experts on this subject based on the ideXlab platform.
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very highly toxic effects of endosulfan across nine species of tadpoles lag effects and family level sensitivity
Environmental Toxicology and Chemistry, 2009Co-Authors: Devin K Jones, John I Hammond, Rick A RelyeaAbstract:Pesticides are commonly used for health and economic benefits worldwide, but increased use has led to increased contamination of aquatic habitats. To understand potential impacts on nontarget organisms in these habitats, toxicologists generally use short-term (4-d) toxicity tests on model organisms. For most pesticides, few amphibian tests have been conducted, but there is growing concern about the potential impact of pesticides to amphibian populations. For the insecticide endosulfan, previous studies have found that low concentrations can be very highly toxic to amphibians and have suggested that this mortality may exhibit important lag effects. To estimate the lethal concentration of endosulfan that would cause 50% mortality after 4 d (LC504-d) across a diversity of amphibians and the presence of lag effects, LC504-d experiments were conducted on nine species of tadpoles from three families (Bufonidae: Bufo americanus, B. boreas; Hylidae: Pseudacris crucifer, P. regilla, Hyla versicolor, and Ranidae: Rana pipiens, R. clamitans, R. cascadae, R. catesbeiana) and then held the animals for an additional 4 d in clean water. The LC504-d values for endosulfan ranged from 1.3 to 120 ppb, which classifies endosulfan as highly toxic to very highly toxic. Moreover, holding the animals for an additional 4 d in clean water revealed significant additional mortality in three of the nine species. Leopard frogs, for example, experienced no significant death during the initial 4-d exposure to 60 ppb but 97% death after an additional 4 d in clean water. A phylogenetic pattern also appears to exist among families, with Bufonidae being least susceptible, Hylidae being moderately susceptible, and Ranidae being most susceptible. Results from the present study provide valuable data to assess the impact of endosulfan on a globally declining group of vertebrates.
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VERY HIGHLY TOXIC EFFECTS OF ENDOSULFAN ACROSS NINE SPECIES OF TADPOLES: LAG EFFECTS AND FAMILY-LEVEL SENSITIVITY
2009Co-Authors: Devin K Jones, John I Hammond, Rick A RelyeaAbstract:Abstract—Pesticides are commonly used for health and economic benefits worldwide, but increased use has led to increased contamination of aquatic habitats. To understand potential impacts on nontarget organisms in these habitats, toxicologists generally use short-term (4-d) toxicity tests on model organisms. For most pesticides, few amphibian tests have been conducted, but there is growing concern about the potential impact of pesticides to amphibian populations. For the insecticide endosulfan, previous studies have found that low concentrations can be very highly toxic to amphibians and have suggested that this mortality may exhibit important lag effects. To estimate the lethal concentration of endosulfan that would cause 50 % mortality after 4 d (LC504-d) across a diversity of amphibians and the presence of lag effects, LC504-d experiments were conducted on nine species of tadpoles from three families (Bufonidae: Bufo americanus, B. boreas; Hylidae: Pseudacris crucifer, P. regilla, Hyla versicolor; and Ranidae: Rana pipiens, R. clamitans, R. cascadae, R. catesbeiana) and then held the animals for an additional 4 d in clean water. The LC504-d values for endosulfan ranged from 1.3 to 120 ppb, which classifies endosulfan as highly toxic to very highly toxic. Moreover, holding the animals for an additional 4 d in clean water revealed significant additional mortality in three of the nine species. Leopard frogs, for example, experienced no significant death during the initial 4-d exposure to 60 ppb but 97 % death after an additional 4 d in clean water. A phylogenetic pattern also appears to exist among families, with Bufonidae being least susceptible, Hylidae being moderately susceptible, and Ranidae being most susceptible. Results from the present study provide valuable data to assess the impact of endosulfan on a globally declining group of vertebrates. Keywords—Ecotoxicology Amphibian decline Nontarget Anuran Contaminan
Rongquan Zheng - One of the best experts on this subject based on the ideXlab platform.
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Complete mitochondrial genomes of Nanorana taihangnica and N. yunnanensis (Anura: Dicroglossidae) with novel gene arrangements and phylogenetic relationship of Dicroglossidae.
BMC evolutionary biology, 2018Co-Authors: Jiayong Zhang, Kenneth B Storey, Le-ping Zhang, Rongquan ZhengAbstract:Complete mitochondrial (mt) genomes have been used extensively to test hypotheses about microevolution and to study population structure, phylogeography, and phylogenetic relationships of Anura at various taxonomic levels. Large-scale mt genomic reorganizations have been observed among many fork-tongued frogs (family Dicroglossidae). The relationships among Dicroglossidae and validation of the genus Feirana are still problematic. Hence, we sequenced the complete mt genomes of Nanorana taihangnica (=F. taihangnica) and N. yunnanensis as well as partial mt genomes of six Quasipaa species (dicroglossid taxa), two Odorrana and two Amolops species (Ranidae), and one Rhacophorus species (Rhacophoridae) in order to identify unknown mt gene rearrangements, to investigate the validity of the genus Feirana, and to test the phylogenetic relationship of Dicroglossidae. In the mt genome of N. taihangnica two trnM genes, two trnP genes and two control regions were found. In addition, the trnA, trnN, trnC, and trnQ genes were translocated from their typical positions. In the mt genome of N. yunnanensis, three control regions were found and eight genes (ND6, trnP, trnQ, trnA, trnN, trnC, trnY and trnS genes) in the L-stand were translocated from their typical position and grouped together. We also found intraspecific rearrangement of the mitochondrial genomes in N. taihangnica and Quasipaa boulengeri. In phylogenetic trees, the genus Feirana nested deeply within the clade of genus Nanorana, indicating that the genus Feirana may be a synonym to Nanorana. Ranidae as a sister clade to Dicroglossidae and the clade of (Ranidae + Dicroglossidae) as a sister clade to (Mantellidae + Rhacophoridae) were well supported in BI analysis but low bootstrap in ML analysis. We found that the gene arrangements of N. taihangnica and N. yunnanensis differed from other published dicroglossid mt genomes. The gene arrangements in N. taihangnica and N. yunnanensis could be explained by the Tandem Duplication and Random Loss (TDRL) and the Dimer-Mitogenome and Non-Random Loss (DMNR) models, respectively. The invalidation of the genus Feirana is supported in this study.
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the complete mitochondrial genome of lithobates sylvaticus anura Ranidae
Mitochondrial DNA, 2015Co-Authors: Ningning Ni, Rongquan Zheng, Danna Yu, Kenneth B Storey, Jiayong ZhangAbstract:AbstractThe complete mitochondrial genome of Lithobates sylvaticus (Anura: Ranidae) was sequenced. The genome is a circular molecule of 17,343 bp in length and contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and a large non-coding region. The gene order and mitochondrial genome information of L. sylvaticus is similar to most other frogs. The overall AT content of L. sylvaticus mitochondrial DNA is 59.3%. In BI and MLtrees, we found L. sylvaticus is a sister clade to L. catesbeianus. The monophyly of Lithobates, Rana, Odorrana, Glandirana, Pelophylax, and Amolops is well supported, but the paraphyly of Babina is supported.
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The complete mitochondrial genome of Babina adenopleura (Anura: Ranidae)
Mitochondrial DNA, 2012Co-Authors: Jiayong Zhang, Rongquan ZhengAbstract:The mitochondrial (mt) genome of Babina adenopleura (Anura: Ranidae) is a circular molecule of 18,982 bp in length, containing 38 genes as well as other anurans. The complete mtDNA of B. adenopleura is 18,982 bp in length, and the A+T content of the overall base composition of H-strand is 58.9% (T, 29.8%; C, 26.6%; A, 29.1%; G, 14.4%). The control regions are 3159 bp in length, and the A+T content of this region is 70.2% (A, 36.6%; C, 16.8%; G, 12.9%; T, 33.6%). The control region possesses distinct repeat regions at both 5′ and 3′ sides. A long space region between ND5 and ND6 genes is 461 bp.
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complete nucleotide sequence and gene organization of the mitochondrial genome of paa spinosa anura ranoidae
Gene, 2009Co-Authors: Yan Zhou, Rongquan Zheng, Jiayong Zhang, Guang YangAbstract:The mt genome of Paa spinosa (Anura: Ranoidae) is a circular molecule of 18,012 bp in length, containing 38 genes (including an extra copy of tRNA-Met gene). This mt genome is characterized by three distinctive features: a cluster of rearranged tRNA genes (LTPF tRNA gene cluster), a tandem duplication of tRNA-Met gene (Met1 and Met2), and distinct repeat regions at both 5' and 3'-sides in the control region. Comparing the locations and the sequences of all tRNA-Met genes among Ranoidae, and constructing NJ tree of the nucleotide of those tRNA-Met genes, we suggested a tandem duplication of tRNA-Met gene can be regarded as a synapomorphy of Dicroglossinae. To further investigate the phylogenetic relationships of anurans, phylogenetic analyses (BI, ML and MP) based on the nucleotide dataset and the corresponding amino acid dataset of 11 protein-coding genes (except ND5 and ATP8) arrived at the similar topology.
Lei Chen - One of the best experts on this subject based on the ideXlab platform.
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the complete mitochondrial genome of dhole cuon alpinus phylogenetic analysis and dating evolutionary divergence within canidae
Molecular Biology Reports, 2011Co-Authors: Hong-hai Zhang, Lei ChenAbstract:The dhole (Cuon alpinus) is the only existent species in the genus Cuon (Carnivora: Canidae). In the present study, the complete mitochondrial genome of the dhole was sequenced. The total length is 16672 base pairs which is the shortest in Canidae. Sequence analysis revealed that most mitochondrial genomic functional regions were highly consistent among canid animals except the CSB domain of the control region. The difference in length among the Canidae mitochondrial genome sequences is mainly due to the number of short segments of tandem repeated in the CSB domain. Phylogenetic analysis was progressed based on the concatenated data set of 14 mitochondrial genes of 8 canid animals by using maximum parsimony (MP), maximum likelihood (ML) and Bayesian (BI) inference methods. The genera Vulpes and Nyctereutes formed a sister group and split first within Canidae, followed by that in the Cuon. The divergence in the genus Canis was the latest. The divarication of domestic dogs after that of the Canis lupus laniger is completely supported by all the three topologies. Pairwise sequence divergence data of different mitochondrial genes among canid animals were also determined. Except for the synonymous substitutions in protein-coding genes, the control region exhibits the highest sequence divergences. The synonymous rates are approximately two to six times higher than those of the non-synonymous sites except for a slightly higher rate in the non-synonymous substitution between Cuon alpinus and Vulpes vulpes. 16S rRNA genes have a slightly faster sequence divergence than 12S rRNA and tRNA genes. Based on nucleotide substitutions of tRNA genes and rRNA genes, the times since divergence between dhole and other canid animals, and between domestic dogs and three subspecies of wolves were evaluated. The result indicates that Vulpes and Nyctereutes have a close phylogenetic relationship and the divergence of Nyctereutes is a little earlier. The Tibetan wolf may be an archaic pedigree within wolf subspecies. The genetic distance between wolves and domestic dogs is less than that among different subspecies of wolves. The domestication of dogs was about 1.56–1.92 million years ago or even earlier.
Jiayong Zhang - One of the best experts on this subject based on the ideXlab platform.
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Complete mitochondrial genomes of Nanorana taihangnica and N. yunnanensis (Anura: Dicroglossidae) with novel gene arrangements and phylogenetic relationship of Dicroglossidae.
BMC evolutionary biology, 2018Co-Authors: Jiayong Zhang, Kenneth B Storey, Le-ping Zhang, Rongquan ZhengAbstract:Complete mitochondrial (mt) genomes have been used extensively to test hypotheses about microevolution and to study population structure, phylogeography, and phylogenetic relationships of Anura at various taxonomic levels. Large-scale mt genomic reorganizations have been observed among many fork-tongued frogs (family Dicroglossidae). The relationships among Dicroglossidae and validation of the genus Feirana are still problematic. Hence, we sequenced the complete mt genomes of Nanorana taihangnica (=F. taihangnica) and N. yunnanensis as well as partial mt genomes of six Quasipaa species (dicroglossid taxa), two Odorrana and two Amolops species (Ranidae), and one Rhacophorus species (Rhacophoridae) in order to identify unknown mt gene rearrangements, to investigate the validity of the genus Feirana, and to test the phylogenetic relationship of Dicroglossidae. In the mt genome of N. taihangnica two trnM genes, two trnP genes and two control regions were found. In addition, the trnA, trnN, trnC, and trnQ genes were translocated from their typical positions. In the mt genome of N. yunnanensis, three control regions were found and eight genes (ND6, trnP, trnQ, trnA, trnN, trnC, trnY and trnS genes) in the L-stand were translocated from their typical position and grouped together. We also found intraspecific rearrangement of the mitochondrial genomes in N. taihangnica and Quasipaa boulengeri. In phylogenetic trees, the genus Feirana nested deeply within the clade of genus Nanorana, indicating that the genus Feirana may be a synonym to Nanorana. Ranidae as a sister clade to Dicroglossidae and the clade of (Ranidae + Dicroglossidae) as a sister clade to (Mantellidae + Rhacophoridae) were well supported in BI analysis but low bootstrap in ML analysis. We found that the gene arrangements of N. taihangnica and N. yunnanensis differed from other published dicroglossid mt genomes. The gene arrangements in N. taihangnica and N. yunnanensis could be explained by the Tandem Duplication and Random Loss (TDRL) and the Dimer-Mitogenome and Non-Random Loss (DMNR) models, respectively. The invalidation of the genus Feirana is supported in this study.
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the complete mitochondrial genome of lithobates sylvaticus anura Ranidae
Mitochondrial DNA, 2015Co-Authors: Ningning Ni, Rongquan Zheng, Danna Yu, Kenneth B Storey, Jiayong ZhangAbstract:AbstractThe complete mitochondrial genome of Lithobates sylvaticus (Anura: Ranidae) was sequenced. The genome is a circular molecule of 17,343 bp in length and contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and a large non-coding region. The gene order and mitochondrial genome information of L. sylvaticus is similar to most other frogs. The overall AT content of L. sylvaticus mitochondrial DNA is 59.3%. In BI and MLtrees, we found L. sylvaticus is a sister clade to L. catesbeianus. The monophyly of Lithobates, Rana, Odorrana, Glandirana, Pelophylax, and Amolops is well supported, but the paraphyly of Babina is supported.
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The complete mitochondrial genome of Babina adenopleura (Anura: Ranidae)
Mitochondrial DNA, 2012Co-Authors: Jiayong Zhang, Rongquan ZhengAbstract:The mitochondrial (mt) genome of Babina adenopleura (Anura: Ranidae) is a circular molecule of 18,982 bp in length, containing 38 genes as well as other anurans. The complete mtDNA of B. adenopleura is 18,982 bp in length, and the A+T content of the overall base composition of H-strand is 58.9% (T, 29.8%; C, 26.6%; A, 29.1%; G, 14.4%). The control regions are 3159 bp in length, and the A+T content of this region is 70.2% (A, 36.6%; C, 16.8%; G, 12.9%; T, 33.6%). The control region possesses distinct repeat regions at both 5′ and 3′ sides. A long space region between ND5 and ND6 genes is 461 bp.
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complete nucleotide sequence and gene organization of the mitochondrial genome of paa spinosa anura ranoidae
Gene, 2009Co-Authors: Yan Zhou, Rongquan Zheng, Jiayong Zhang, Guang YangAbstract:The mt genome of Paa spinosa (Anura: Ranoidae) is a circular molecule of 18,012 bp in length, containing 38 genes (including an extra copy of tRNA-Met gene). This mt genome is characterized by three distinctive features: a cluster of rearranged tRNA genes (LTPF tRNA gene cluster), a tandem duplication of tRNA-Met gene (Met1 and Met2), and distinct repeat regions at both 5' and 3'-sides in the control region. Comparing the locations and the sequences of all tRNA-Met genes among Ranoidae, and constructing NJ tree of the nucleotide of those tRNA-Met genes, we suggested a tandem duplication of tRNA-Met gene can be regarded as a synapomorphy of Dicroglossinae. To further investigate the phylogenetic relationships of anurans, phylogenetic analyses (BI, ML and MP) based on the nucleotide dataset and the corresponding amino acid dataset of 11 protein-coding genes (except ND5 and ATP8) arrived at the similar topology.
