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.

scholarly journals Studies on the Scutellar Bristles of Drosophila melanogaster. IV. Selection for Low Bristle Number in Oregon-RC Wild-type Lines

1984 ◽  
Vol 37 (4) ◽  
pp. 277
Author(s):  
BL Sheldon ◽  
M K Evans
Keyword(s):  
Recessive Gene ◽  
Population Level ◽  
Initial Response ◽  
The Other ◽  
Selection Line ◽  
Base Population ◽  
Wild Type ◽  
Threshold Phenomenon ◽  
Bristle Number ◽  
Selection For

Results are presented of 130-145 generations of selection for low scutellar bristle number in four lines of D. melanogaster derived directly from an Oregon-RC wild-type stock and in one derived from an Oregon-RC line selected for low sternital bristle number. The most rapid initial response and the lowest mean scutellar bristle number ultimately reached, just below 2 bristles, occurred in a line in which the response was due to a new recessive gene located at approximately 17�4 on the X chromosome. Three of the other four lines reached a plateau just above a mean of 2 bristles after different patterns of response. These plateaux reflected a new canalization or threshold phenomenon at 2 bristles in these lines. The remaining line reached a mean of about 2� 5 bristles after some 50 generations and remained at that level or slightly higher thereafter, but had no indication of canalization at 2 bristles. Two relaxed lines were derived from each selection line at different times and showed variable patterns of regression towards the base population level.

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.

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%.

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

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 Acclimation and Selection for Increased Resistance to Thermal Stress in Drosophila buzzatii

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 471-479 ◽  
Author(s):  
Robert A Krebs ◽  
Volker Loeschcke
Keyword(s):  
Heat Shock ◽  
Direct Selection ◽  
Selection Line ◽  
Base Population ◽  
Cytoplasmic Effects ◽  
Drosophila Buzzatii ◽  
Direct Exposure ◽  
Shock Resistance ◽  
Selection For ◽  
And Control

Abstract Direct selection for increased resistance to a heat shock (41.9° for 90 min) was carried out using two replicate lines of Drosophila buzzatii that were derived from a large base population. Selected individuals were first acclimated to high temperature before selection, while control individuals were acclimated but not selected, and selection was performed every second generation. Resistance to heat shock with acclimation increased in selected lines. Without acclimation, a correlated smaller increase in heat-shock resistance was suggested. Survival of males was higher than that of females in all lines when tested with acclimation, but with direct exposure to high temperatures, survival of females was greater than that of males both in selection and control lines but not in the base population. From analysis of reciprocal cross progeny between lines, one selection line was found to possess a dominant autosomal factor that significantly increased resistance of males much more than resistance of females. Also suggestive was recessive traits on the X chromosome in both selection lines that increased thermotolerance. No cytoplasmic effects were found. After accounting for other effects, survival of F1 flies was intermediate, suggesting that additive variation is present for one or more of the autosomes.

Selection alters the pattern of emergence from the host cadaver in the entomopathogenic nematode, Steinernema glaseri

Parasitology ◽  
1996 ◽  
Vol 113 (2) ◽  
pp. 183-189 ◽  
Author(s):  
R. J. Stuart ◽  
E. E. Lewis ◽  
R. Gaugler
Keyword(s):  
Entomopathogenic Nematode ◽  
Natural Populations ◽  
Genetic Component ◽  
Infective Juvenile ◽  
Base Population ◽  
Emergence Period ◽  
Emergence Pattern ◽  
Steinernema Glaseri ◽  
Complex Life History ◽  
Selection For

SUMMARYWe used selection to test for a genetic component to the pattern of emergence of infective juveniles from the host cadaver in the entomopathogenic nematode, Steinernema glaseri (Steiner), and whether other traits would respond to selection on this major and complex life-history character. We selected for early (‘ fast’) and late (‘ slow’) emerging lines by perpetuating nematodes that emerged on the first and after the seventh day of emergence respectively. After 12 cycles of selection, the pattern for the slow line but not the fast line differed significantly from the base population. Cumulative emergence for the slow line was less than the base population from Days 4 to 14 of the 18-day emergence period. The maximum difference occurred on the fourth day when 72·6% of emergence was complete for the base population but only 55·4% for the slow line. Decreases in infective juvenile size over the emergence period were consistent with the change in emergence pattern, but variation in sex ratios was not. No differences in infectivity were found. These results indicate that the emergence pattern has a genetic component, and that genetic variability for this trait occurs in natural populations. Furthermore, the asymmetric response to selection suggests that our field population is under strong selection for a highly skewed early emergence.

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.

Resistance to DDT in the catle trick, Boophilus microplus (Canestrini)

1957 ◽  
Vol 8 (4) ◽  
pp. 424 ◽  
Author(s):  
BF Stone
Keyword(s):  
Resistant Strain ◽  
Boophilus Microplus ◽  
Susceptible Strain ◽  
Cattle Tick ◽  
Three Generations ◽  
Adult Females ◽  
Selection For

Difficulty was experienced in controlling the cattle tick, on a herd at Rockhampton in central Queensland, by dipping in 0.5 per cent. w/v pp'-DDT. When an animal artificially infested with this strain was sprayed with 1 per cent. w/v pp'-DDT, only 26 per cent. of the engorged females falling from the animal over the 48-hr period after spraying failed to lay viable eggs, as compared with 64 per cent. of susceptible ticks falling from a similarly treated aninial. Both strains were, however, equally susceptible to "Diazinon". Laboratory concentration-response tests with a culture of the Rockhampton ticks indicated that the larvae exhibited a resistance 22 times that of a susceptible strain, and the engorged adult females a degree of resistance probably of the same order. The Rockhampton strain showed no significant resistance to dieldrin or toxaphene. There was no difference in susceptibility to DDT between adults of an 'early-falling' and a "late-falling" substrain of the resistant strain after selection for three generations.

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