Gong T

References (6)

Title : Acetylcholinesterase Activity Staining in Freshwater Planarians - Rabeler_2023_Curr.Protoc_3_e674
Author(s) : Rabeler C , Gong T , Ireland D , Cochet-Escartin O , Collins ES
Ref : Curr Protoc , 3 :e674 , 2023
Abstract : The serine hydrolase acetylcholinesterase (AChE) is an important neuronal enzyme which catalyzes the hydrolysis of the neurotransmitter acetylcholine and other choline esters. The breakdown of acetylcholine by AChE terminates synaptic transmission and regulates neuromuscular communication. AChE inhibition is a common mode of action of various insecticides, such as carbamates and organophosphorus pesticides. Freshwater planarians, especially the species Dugesia japonica, have been shown to possess AChE activity and to be a suitable alternative model for studying the effects of pesticides in vivo. AChE activity can be quantified in homogenates using the Ellman assay. However, this biochemical assay requires specialized equipment and large numbers of planarians. Here, we present a protocol for visualizing AChE activity in individual planarians. Activity staining can be completed in several hours and can be executed using standard laboratory equipment (a fume hood, nutator, and light microscope with imaging capability). We describe the steps for preparing the reagents, and the staining and imaging of the planarians. Planarians are treated with 10% acetic acid and fixed with 4% paraformaldehyde and then incubated in a staining solution containing the substrate acetylthiocholine. After incubation in the staining solution for 3.5 hr on a nutator at 4 degreesC, or stationary on ice, planarians are washed and mounted for imaging. Using exposure to an organophosphorus pesticide as an example, we show how AChE inhibition leads to a loss of staining. Thus, this simple method can be used to qualitatively evaluate AChE inhibition due to chemical exposure or RNA interference, providing a new tool for mechanistic studies of effects on the cholinergic system. 2023 Wiley Periodicals LLC. Basic Protocol 1: Preparing the staining solution Basic Protocol 2: Fixing, staining, and imaging whole-mount planarian specimens for visualization of acetylcholinesterase activity.
ESTHER : Rabeler_2023_Curr.Protoc_3_e674
PubMedSearch : Rabeler_2023_Curr.Protoc_3_e674
PubMedID: 36799654

Title : Bioactivation and detoxification of organophosphorus pesticides in freshwater planarians shares similarities with humans - Ireland_2022_Arch.Toxicol__
Author(s) : Ireland D , Rabeler C , Gong T , Collins ES
Ref : Archives of Toxicology , : , 2022
Abstract : Organophosphorus pesticides (OPs) are a chemically diverse class of insecticides that inhibit acetylcholinesterase (AChE). Many OPs require bioactivation to their active oxon form via cytochrome P450 to effectively inhibit AChE. OP toxicity can be mitigated by detoxification reactions performed by carboxylesterase and paraoxonase. The relative extent of bioactivation to detoxification varies among individuals and between species, leading to differential susceptibility to OP toxicity. Because of these species differences, it is imperative to characterize OP metabolism in model systems used to assess OP toxicity. We have shown that the asexual freshwater planarian Dugesia japonica is a suitable model to assess OP neurotoxicity and developmental neurotoxicity via rapid, automated testing of adult and developing organisms in parallel using morphological and behavioral endpoints. D. japonica has two cholinesterase enzymes with intermediate properties between AChE and butyrylcholinesterase that are sensitive to OP inhibition. Here, we demonstrate that D. japonica contains the major OP metabolic machinery to be a relevant model for OP neurotoxicity studies. Adult and regenerating D. japonica can bioactivate chlorpyrifos and diazinon into their respective oxons. Significant AChE inhibition was only observed after in vivo metabolic activation but not when the parent OPs were directly added to planarian homogenate using the same concentrations and timing. Using biochemical assays, we found that D. japonica has both carboxylesterase (24 nmol/(min*mg protein)) and paraoxonase (60 pmol/(min*mg protein)) activity. We show that planarian carboxylesterase activity is distinct from cholinesterase activity using benzil and tacrine. These results further support the use of D. japonica for OP toxicity studies.
ESTHER : Ireland_2022_Arch.Toxicol__
PubMedSearch : Ireland_2022_Arch.Toxicol__
PubMedID: 36173421

Title : Engineering Pseudomonas putida KT2440 for simultaneous degradation of organophosphates and pyrethroids and its application in bioremediation of soil - Zuo_2015_Biodegradation_26_223
Author(s) : Zuo Z , Gong T , Che Y , Liu R , Xu P , Jiang H , Qiao C , Song C , Yang C
Ref : Biodegradation , 26 :223 , 2015
Abstract : Agricultural soils are usually co-contaminated with organophosphate (OP) and pyrethroid pesticides. To develop a stable and marker-free Pseudomonas putida for co-expression of two pesticide-degrading enzymes, we constructed a suicide plasmid with expression cassettes containing a constitutive promoter J23119, an OP-degrading gene (mpd), a pyrethroid-hydrolyzing carboxylesterase gene (pytH) that utilizes the upp gene as a counter-selectable marker for upp-deficient P. putida. By introduction of suicide plasmid and two-step homologous recombination, both mpd and pytH genes were integrated into the chromosome of a robust soil bacterium P. putida KT2440 and no selection marker was left on chromosome. Functional expression of mpd and pytH in P. putida KT2440 was demonstrated by Western blot analysis and enzyme activity assays. Degradation experiments with liquid cultures showed that the mixed pesticides including methyl parathion, fenitrothion, chlorpyrifos, permethrin, fenpropathrin, and cypermethrin (0.2 mM each) were degraded completely within 48 h. The inoculation of engineered strain (10(6) cells/g) to soils treated with the above mixed pesticides resulted in a higher degradation rate than in noninoculated soils. All six pesticides could be degraded completely within 15 days in fumigated and nonfumigated soils with inoculation. Theses results highlight the potential of the engineered strain to be used for in situ bioremediation of soils co-contaminated with OP and pyrethroid pesticides.
ESTHER : Zuo_2015_Biodegradation_26_223
PubMedSearch : Zuo_2015_Biodegradation_26_223
PubMedID: 25917649

Title : An upp-based markerless gene replacement method for genome reduction and metabolic pathway engineering in Pseudomonas mendocina NK-01 and Pseudomonas putida KT2440 - Wang_2015_J.Microbiol.Methods_113_27
Author(s) : Wang Y , Zhang C , Gong T , Zuo Z , Zhao F , Fan X , Yang C , Song C
Ref : J Microbiol Methods , 113 :27 , 2015
Abstract : A markerless gene replacement method was adapted by combining a suicide plasmid, pEX18Tc, with a counterselectable marker, the upp gene encoding uracil phosphoribosyltransferase (UPRTase), for the medium-chain length polyhydroxyalkanoates (PHAMCL)-producing strain Pseudomonas mendocina NK-01. An NK-01 5-fluorouracil (5-FU) resistant background strain was first constructed by deleting the chromosomal upp gene. The suicide plasmid pEX18Tc, carrying a functional allele of the upp gene of P. mendocina NK-01, was used to construct the vectors to delete the algA (encoding mannose-1-phosphate guanylyltransferase) and phaZ (encoding PHAMCL depolymerase) genes, and a 30kb chromosomal fragment in the 5-FU resistant background host. The genes were removed efficiently from the genome of P. mendocina NK-01 and left a markerless chromosomal mutant. In addition, two exogenous genes were inserted into the phaC1 (PHAMCL polymerase) loci of Pseudomonas putida KT-UPP simultaneously. Thus, we constructed a genetically stable and marker-free P. putida KT2440 mutant with integrated mpd (encoding methyl parathion hydrolase (MPH)) and pytH (encoding a pyrethroid-hydrolyzing carboxylesterase (PytH)) gene on the chromosome. The upp-based counterselection system could be further adapted for P. mendocina NK-01 and P. putida KT2440 and used for genome reduction and metabolic pathway engineering.
ESTHER : Wang_2015_J.Microbiol.Methods_113_27
PubMedSearch : Wang_2015_J.Microbiol.Methods_113_27
PubMedID: 25828098

Title : Genome Sequence of the epsilon-Poly-l-Lysine-Producing Strain Streptomyces albulus NK660, Isolated from Soil in Gutian, Fujian Province, China - Gu_2014_Genome.Announc_2_e00532
Author(s) : Gu Y , Yang C , Wang X , Geng W , Sun Y , Feng J , Wang Y , Quan Y , Che Y , Zhang C , Gong T , Zhang W , Gao W , Zuo Z , Song C , Wang S
Ref : Genome Announc , 2 :e00532 , 2014
Abstract : We determined the complete genome sequence of a soil bacterium, Streptomyces albulus NK660. It can produce epsilon-poly-l-lysine, which has antimicrobial activity against a spectrum of microorganisms. The genome of S. albulus NK660 contains a 9,360,281-bp linear chromosome and a 12,120-bp linear plasmid.
ESTHER : Gu_2014_Genome.Announc_2_e00532
PubMedSearch : Gu_2014_Genome.Announc_2_e00532
PubMedID: 24926050
Gene_locus related to this paper: stra9-a0a059w351

Title : The sequence and de novo assembly of the giant panda genome - Li_2010_Nature_463_311
Author(s) : Li R , Fan W , Tian G , Zhu H , He L , Cai J , Huang Q , Cai Q , Li B , Bai Y , Zhang Z , Zhang Y , Wang W , Li J , Wei F , Li H , Jian M , Nielsen R , Li D , Gu W , Yang Z , Xuan Z , Ryder OA , Leung FC , Zhou Y , Cao J , Sun X , Fu Y , Fang X , Guo X , Wang B , Hou R , Shen F , Mu B , Ni P , Lin R , Qian W , Wang G , Yu C , Nie W , Wang J , Wu Z , Liang H , Min J , Wu Q , Cheng S , Ruan J , Wang M , Shi Z , Wen M , Liu B , Ren X , Zheng H , Dong D , Cook K , Shan G , Zhang H , Kosiol C , Xie X , Lu Z , Li Y , Steiner CC , Lam TT , Lin S , Zhang Q , Li G , Tian J , Gong T , Liu H , Zhang D , Fang L , Ye C , Zhang J , Hu W , Xu A , Ren Y , Zhang G , Bruford MW , Li Q , Ma L , Guo Y , An N , Hu Y , Zheng Y , Shi Y , Li Z , Liu Q , Chen Y , Zhao J , Qu N , Zhao S , Tian F , Wang X , Wang H , Xu L , Liu X , Vinar T , Wang Y , Lam TW , Yiu SM , Liu S , Huang Y , Yang G , Jiang Z , Qin N , Li L , Bolund L , Kristiansen K , Wong GK , Olson M , Zhang X , Li S , Yang H
Ref : Nature , 463 :311 , 2010
Abstract : Using next-generation sequencing technology alone, we have successfully generated and assembled a draft sequence of the giant panda genome. The assembled contigs (2.25 gigabases (Gb)) cover approximately 94% of the whole genome, and the remaining gaps (0.05 Gb) seem to contain carnivore-specific repeats and tandem repeats. Comparisons with the dog and human showed that the panda genome has a lower divergence rate. The assessment of panda genes potentially underlying some of its unique traits indicated that its bamboo diet might be more dependent on its gut microbiome than its own genetic composition. We also identified more than 2.7 million heterozygous single nucleotide polymorphisms in the diploid genome. Our data and analyses provide a foundation for promoting mammalian genetic research, and demonstrate the feasibility for using next-generation sequencing technologies for accurate, cost-effective and rapid de novo assembly of large eukaryotic genomes.
ESTHER : Li_2010_Nature_463_311
PubMedSearch : Li_2010_Nature_463_311
PubMedID: 20010809
Gene_locus related to this paper: ailme-ABH15 , ailme-ACHE , ailme-BCHE , ailme-d2gtv3 , ailme-d2gty9 , ailme-d2gu87 , ailme-d2gu97 , ailme-d2gve7 , ailme-d2gwu1 , ailme-d2gx08 , ailme-d2gyt0 , ailme-d2gz36 , ailme-d2gz37 , ailme-d2gz38 , ailme-d2gz39 , ailme-d2gz40 , ailme-d2h5r9 , ailme-d2h7b7 , ailme-d2h9c9 , ailme-d2h794 , ailme-d2hau7 , ailme-d2hau8 , ailme-d2hcd9 , ailme-d2hdi6 , ailme-d2heu6 , ailme-d2hga4 , ailme-d2hqw5 , ailme-d2hs98 , ailme-d2hsx4 , ailme-d2hti6 , ailme-d2htv3 , ailme-d2htz6 , ailme-d2huc7 , ailme-d2hwj8 , ailme-d2hwy7 , ailme-d2hxm1 , ailme-d2hyc8 , ailme-d2hyv2 , ailme-d2hz11 , ailme-d2hza3 , ailme-d2hzr4 , ailme-d2i1l4 , ailme-d2i2g8 , ailme-g1l7m3 , ailme-g1lu36 , ailme-g1m769 , ailme-g1mc29 , ailme-g1mdj8 , ailme-g1mdr5 , ailme-g1mfp4 , ailme-g1mfx5 , ailme-g1lj41 , ailme-g1lm28 , ailme-g1l3u1 , ailme-g1l7l1 , ailme-g1m5i3 , ailme-g1l2f6 , ailme-g1lji5 , ailme-g1lqk3 , ailme-g1l8s9 , ailme-d2h717 , ailme-d2h718 , ailme-d2h719 , ailme-d2h720 , ailme-g1m5v0 , ailme-g1m5y7 , ailme-g1lkt7 , ailme-g1l2a1 , ailme-g1lsc8 , ailme-g1lrp4 , ailme-d2gv02 , ailme-g1mik5 , ailme-g1ljr1 , ailme-g1lxw7 , ailme-d2h8b5 , ailme-d2h2r2 , ailme-d2h9w7 , ailme-g1meh3 , ailme-g1m719