Some properties of l-chloro-2,4-dinitrochlorobenzene linked glutathione S-transferase in dichlorvos resistant and susceptible strains of cotton aphid (Homoptera: Aphididae)

1996 ◽  
Vol 127 (4) ◽  
pp. 469-473 ◽  
Author(s):  
E. O. Owusu ◽  
M. Horiike
Keyword(s):  
Enzyme Activity ◽  
Resistant Strain ◽  
Aphis Gossypii ◽  
Susceptible Strain ◽  
Glutathione S Transferase ◽  
Cotton Aphid ◽  
High Positive Correlation ◽  
Application Frequency ◽  
Resistant Strains ◽  
Two Parameters

SUMMARYEffects of temperature, hydrogen ion and substrate concentrations on conjugation of l-chloro-2,4-dinitrochlorobenzene by glutathione S-transferase from susceptible and dichlorvos-resistant strains of cotton aphid (Aphis gossypii Glover (Homoptera: Aphididae)) were evaluated. Enzymes from both strains had common optimum temperature and substrate concentration values of 30 °C and 10 mM respectively. Also, while enzyme activity of the susceptible strain peaked at pH 7·2, that of the resistant strain showed complete linear dependency up to pH 8·0. Of four subcellular fractions, the 100 000 g supernatant (soluble fraction) gave the highest enzyme activity in both phosphate and Tris/HCl buffers. There was no linear relationship between insecticide application frequency and production of enzyme activity in the susceptible strain but there was a very high positive correlation between these two parameters in the resistant strain.

scholarly journals Polygenic and single gene responses to selection for resistance to diazinon in Lucilia cuprina.

Genetics ◽  
1992 ◽  
Vol 130 (3) ◽  
pp. 613-620 ◽  
Author(s):  
J A McKenzie ◽  
A G Parker ◽  
J L Yen
Keyword(s):  
Resistant Strain ◽  
Single Gene ◽  
Natural Populations ◽  
Susceptible Strain ◽  
Selection Line ◽  
Base Population ◽  
Gene Response ◽  
Biochemical Profiles ◽  
Resistant Strains ◽  
Selection For

Abstract Following mutagenesis with ethyl methanesulfonate, selection in a susceptible strain with a concentration of the insecticide diazinon (0.0004%, w/v) above that required to kill 100% of the susceptible strain, the LC100 of that strain, resulted in a single gene response. The resultant four mutant resistant strains have equivalent physiological, genetical and biochemical profiles to a diazinon-resistant strain derived from a natural population and homozygous for the Rop-1 allele. Modification of the microsomal esterase E3 is responsible for resistance in each case. The Rop-1 locus maps approximately 4.4 map units proximal to bu on chromosome IV. Selection within the susceptible distribution, at a concentration of diazinon [0.0001% (w/v)] less than the LC100, resulted in a similar phenotypic response irrespective of whether the base population had been mutagenized. The responses were polygenically based, unique to each selection line and independent of Rop-1. The relevance of the results to selection for insecticide resistance in laboratory and natural populations is discussed.

scholarly journals In vitro anti-mycobacterial activity of (E)-N´-(monosubstituted-benzylidene) isonicotinohydrazide derivatives against isoniazid-resistant strains

2012 ◽  
Vol 4 (1) ◽  
pp. 13 ◽  
Author(s):  
Tatiane S. Coelho ◽  
Jessica B. Cantos ◽  
Marcelle L.F. Bispo ◽  
Raoni S.B. Gonçalves ◽  
Camilo H.S. Lima ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Resistant Strain ◽  
Mechanisms Of Action ◽  
Susceptible Strain ◽  
Clinical Isolates ◽  
Coding Region ◽  
Resistant Strains

A series of twenty-three <em>N-acylhydrazones</em> derived from isoniazid (INH 1-23) have been evaluated for their <em>in vitro</em> antibacterial activity against INH- susceptible strain of <em>M. tuberculosis</em> (RG500) and three INH-resistant clinical isolates (RG102, RG103 and RG113). In general, derivatives 4, 14, 15 and 16 (MIC=1.92, 1.96, 1.96 and 1.86 mM, respectively) showed relevant activities against RG500 strain, while the derivative 13 (MIC=0.98 mM) was more active than INH (MIC=1.14 mM). However, these derivatives were inactive against RGH102, which displays a mutation in the coding region of <em>inhA</em>. These results suggest that the activities of these compounds depend on the inhibition of this enzyme. However, the possibility of other mechanisms of action cannot be excluded, since compounds 2, 4, 6, 7, 12-17, 19, 21 and 23 showed good activities against <em>katG</em>-resistant strain RGH103, being more than 10-fold more active than INH.

Comparisons Between the Response of German Cockroach Field-Collected Strains (Dictyoptera: Blattellidae) to Vapors and Contact with a Cyfluthrin Formulation

1993 ◽  
Vol 28 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Mary H. Ross
Keyword(s):  
Resistant Strain ◽  
German Cockroach ◽  
Susceptible Strain ◽  
Late Instar ◽  
Resistant Strains ◽  
Biochemical Resistance

Research on differences in insecticide-induced behavior of German cockroach field-collected strains was continued. Late instar nymphs (5th–6th stadia) were drawn from the Fairbanks, an insecticide susceptible strain, and two pyrethroid resistant strains, the Jacksonville and Forest Green. Dispersal induced by vapors of a cyfluthrin flowable concentrate (FC) and the FC formulation base (blank) was compared with response to the FC and the FC blank when dry. Jacksonville nymphs avoided the dried FC, but not as strongly as Fairbanks strain nymphs. The Al played a major role in eliciting avoidance by Fairbanks strain nymphs but, in the Jacksonville strain, avoidance was due more to an ingredient(s) of the formulation base. Forest Green nymphs did not avoid the dried FC or the FC blank. Vapors of the FC and the FC blank caused rapid dispersal of all strains, but dispersal of resistant strain nymphs was slower than that of susceptible strain nymphs. Although Jacksonville nymphs responded more strongly to the dried formulation than Forest Green nymphs, the response to vapors was weaker than that of Forest Green nymphs. It is suggested that localized populations of the German cockroach have developed many different combinations of behavioral modifications and physiological/biochemical resistance.

scholarly journals The role of detoxifying enzymes in the resistance of the cowpea aphid (Aphis craccivora Koch) to thiamethoxam

2016 ◽  
Vol 56 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Ibrahim Saleh Abdallah ◽  
Hala Mohamed Abou-Yousef ◽  
Eman Atef Fouad ◽  
Mohammed Abd El-Hady Kandil
Keyword(s):  
Resistant Strain ◽  
Insect Pest ◽  
Aphis Craccivora ◽  
Susceptible Strain ◽  
Cross Resistance ◽  
Glutathione S Transferase ◽  
Detoxifying Enzymes ◽  
Cowpea Aphid ◽  
Aphis Craccivora Koch

Abstract The cowpea aphid (Aphis craccivora Koch) is considered a serious insect pest attacking several crops. We carried out biochemical studies to elucidate the role of the metabolising enzymes in conferring resistance to thiamethoxam, in two strains (resistant and susceptible) of the cowpea aphid. Bioassay experiments showed that the thiamethoxam selected strain developed a 48 fold resistance after consecutive selection with thiamethoxam for 12 generations. This resistant strain also exhibited cross-resistance to the tested carbamates; pirimicarb and carbosulfan, organophosphorus (malathion, fenitrothion, and chlorpyrifos-methyl), and the neonicotinoid (acetamiprid). Synergism studies have indicated that S,S,S-tributyl phosphorotrithioate (DEF), a known inhibitor for esterases, increased thiamethoxam toxicity 5.58 times in the resistant strain compared with the susceptible strain. Moreover, the biochemical determination revealed that carboxylestersae activity was 30 times greater in the resistant strain than in the susceptible strain. In addition, the enzyme activity of glutathione S-transferase (GST) and mixed function oxidases (mfo) increased only in the resistant strain 3.7 and 2.7 times, respectively, in relation to the susceptible (the control). Generally, our results suggest that the higher activity of the detoxifying enzymes, particularly carboxylesterase, in the resistant strain of the cowpea aphid, apparently have a significant role in endowing resistance to thiamethoxam, although additional mechanisms may contribute.

CROSSOVER VALUES BETWEEN DIELDRIN-RESISTANCE AND DDT-RESISTANCE AND LINKAGE-GROUP-2 GENES IN AEDES AEGYPTI

1970 ◽  
Vol 12 (3) ◽  
pp. 407-414 ◽  
Author(s):  
W. L. Lockhart ◽  
W. Klassen ◽  
A. W. A. Brown
Keyword(s):  
Linkage Group ◽  
Aedes Aegypti ◽  
Resistant Strain ◽  
Susceptible Strain ◽  
Total Distance ◽  
Resistant Strains ◽  
Ddt Resistance ◽  
Group 2

Crosses and backcrosses between five dieldrin-resistant strains and the MYS susceptible strain in Aedes aegypti indicate the order of the genes to be Dl—si — s, the distance si — s being 6-7 units and the total distance Dl — s being 25-31 units.Crosses between the Trinidad DDT-resistant strain and the MYS marker strain indicate the order to be si — s — DDT, the distance si — s being 4 units and the total distance s — DDT being 10 units. Crosses between this strain and the AO and Multiple marker strains indicate the order to be y — s — DDT.These results indicate that the order of the genes in linkage-group 2 of Aedes aegypti is probably Dl — si — y —s — DDT. The total crossover distance of some 45 units thus implied between Dl and DDT is, however, at variance with previous work which found the direct crossover between these two genes to be only 4-7%.

Physiological Competence of Atrazine-Resistant Strains of the Photosynthetic BacteriumRhodobacter sphaeroides(Rhodospirillaceae)

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 703-706 ◽  
Author(s):  
Alfred E. Brown ◽  
Bryan Truelove ◽  
Claudia T. Highfill ◽  
Scott G. Smith
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Resistant Strain ◽  
Type Strain ◽  
Wild Type Strain ◽  
Photosynthetic Bacterium ◽  
Optimal Conditions ◽  
Wild Type ◽  
Culture Study ◽  
Resistant Strains ◽  
Two Parameters

Two parameters of physiological competence, rate of CO2fixation and intraspecific competitiveness, were determined for one or more atrazine-resistant isolates of the photosynthetic bacteriumRhodobacter sphaeroides. Measured over a 2-h period under optimal conditions, two of the resistant isolates fixed CO2at a greater rate than the atrazine-susceptible, wild-type organism. In a mixed culture study, an atrazine-resistant strain was able to grow and compete successfully with the susceptible, wild-type strain for at least 14 days.

THE PRODUCTION OF A DDT-RESISTANT STRAIN OF AEDES AEGYPTI MARKED ON ALL THREE LINKAGE GROUPS

1974 ◽  
Vol 16 (4) ◽  
pp. 883-888 ◽  
Author(s):  
J. P. Margham ◽  
R. J. Wood
Keyword(s):  
Aedes Aegypti ◽  
Resistance Genes ◽  
Resistant Strain ◽  
Genetic Background ◽  
Adult Stage ◽  
Susceptible Strain ◽  
Linkage Studies ◽  
Linkage Groups ◽  
Resistant Strains ◽  
Major Resistance Genes

DDT-resistant strains marked on all three linkage groups have been produced by selection at the adult stage after outcrossing a resistant strain (BANGKOK-HR) to a marked susceptible strain (64). The most resistant and viable line (BANGKOK-MR) was kept for linkage studies. The production of a marked resistant strain was not entirely straightforward. In the absence of a suitable genetic background, major resistance genes conferred little or no DDT tolerance and could not be selected. Selection at the adult stage produced resistance in larvae as well as in adults. Resistance was achieved more rapidly in larvae than in adults

scholarly journals Development and Characterization of Diamondback Moth Resistance to Transgenic Broccoli Expressing High Levels of Cry1C

2000 ◽  
Vol 66 (9) ◽  
pp. 3784-3789 ◽  
Author(s):  
Jian-Zhou Zhao ◽  
Hilda L. Collins ◽  
Juliet D. Tang ◽  
Jun Cao ◽  
Elizabeth D. Earle ◽  
...  
Keyword(s):  
Resistant Strain ◽  
Diamondback Moth ◽  
Membrane Vesicles ◽  
Continuous Selection ◽  
Susceptible Strain ◽  
Recessive Factor ◽  
Major Mechanism ◽  
Resistant Strains ◽  
Transgenic Broccoli

ABSTRACT A field-collected colony of the diamondback moth, Plutella xylostella, had 31-fold resistance to Cry1C protoxin ofBacillus thuringiensis. After 24 generations of selection with Cry1C protoxin and transgenic broccoli expressing a Cry1C protein, the resistance that developed was high enough that neonates of the resistant strain could complete their entire life cycle on transgenic broccoli expressing high levels of Cry1C. After 26 generations of selection, the resistance ratios of this strain to Cry1C protoxin were 12,400- and 63,100-fold, respectively, for the neonates and second instars by a leaf dip assay. The resistance remained stable until generation 38 (G38) under continuous selection but decreased to 235-fold at G38 when selection ceased at G28. The Cry1C resistance in this strain was seen to be inherited as an autosomal and incompletely recessive factor or factors when evaluated using a leaf dip assay and recessive when evaluated using Cry1C transgenic broccoli. Saturable binding of 125I-Cry1C was found with brush border membrane vesicles (BBMV) from both susceptible and Cry1C-resistant strains. Significant differences in Cry1C binding to BBMV from the two strains were detected. BBMV from the resistant strain had about sevenfold-lower affinity for Cry1C and threefold-higher binding site concentration than BBMV from the susceptible strain. The overall Cry1C binding affinity was just 2.5-fold higher for BBMV from the susceptible strain than it was for BBMV from the resistant strain. These results suggest that reduced binding is not the major mechanism of resistance to Cry1C.

scholarly journals UDP-Glycosyltransferases from the UGT344 Family Are Involved in Sulfoxaflor Resistance in Aphis gossypii Glover

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 356
Author(s):  
Kangsheng Ma ◽  
Qiuling Tang ◽  
Pingzhuo Liang ◽  
Jianhong Li ◽  
Xiwu Gao
Keyword(s):  
Resistant Strain ◽  
Transcriptome Sequencing ◽  
Synergistic Effects ◽  
Aphis Gossypii ◽  
Susceptible Strain ◽  
Detoxification Enzymes ◽  
Quantitative Real Time Pcr ◽  
Aphis Gossypii Glover ◽  
Nucleotide Sugars ◽  
Exogenous Compounds

UDP-glycosyltransferases (UGTs) are major phase II detoxification enzymes that catalyze the transfer of glycosyl residues from activated nucleotide sugars to acceptor hydrophobic molecules and play very important roles in the biotransformation of various endogenous and exogenous compounds. Our previous studies demonstrated that UGTs participated in the detoxification of insecticides in Aphis gossypii. However, the potential roles of UGTs in A. gossypii resistance to sulfoxaflor are still unclear. In this study, two inhibitors of UGT enzymes, sulfinpyrazone and 5-nitrouracil, significantly increased the toxicity of sulfoxaflor to a resistant strain of A. gossypii, whereas there were no synergistic effects in the susceptible strain. Based on the transcriptome sequencing results, the expression levels of 15 UGTs were analyzed by quantitative real-time PCR, and we found that seven UGT genes were highly over-expressed in a sulfoxaflor-resistant strain compared to the susceptible strain, including UGT344B4, UGT344C5, UGT344A11, UGT344A14, and UGT344L2. Further suppressing the expression of UGT344B4, UGT344C5, and UGT344A11 by RNA interference significantly increased the sensitivity of resistant aphids to sulfoxaflor, indicating that the overexpression of UGT genes is potentially associated with sulfoxaflor resistance. These results could provide valuable information for further understanding the mechanisms of insecticide resistance.

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