Dehydrochlorination and DDT-Resistance in Aedes aegypti

1963 ◽  
Vol 56 (4) ◽  
pp. 511-517 ◽  
Author(s):  
Z. H. Abedi ◽  
J. R. Duffy ◽  
A. W. A. Brown
Keyword(s):  
1975 ◽  
Vol 17 (3) ◽  
pp. 311-322 ◽  
Author(s):  
Judith M. Hitchen ◽  
R. J. Wood

The gene RDDT2, which gives resistance to DDT in the imago of Aedes aegypti L. has been mapped on linkage group III with respect to six visible markers. The best interpretation of the order of the genes is:–blp – blt – co – fz – wi – RDDT2 – min, but the orderblp – blt – co – fz – RDDT2 – wi – min is also possible.


1962 ◽  
Vol 53 (2) ◽  
pp. 287-299 ◽  
Author(s):  
R. J. Wood

Oviposition time (the time from blood-meal to egg deposition) has been investigated in five strains of Aedes aegypti (L.), two being DDT-resistant (from Trinidad and Haiti) and three susceptible (from West Africa (2) and Haiti). All the strains except the two DDT-resistant ones differed significantly from one another in mean oviposition time.There was a close correlation between mean oviposition time, oviposition period (the over-all period during which eggs are laid) and ‘oviposition light preference’, both the former being greater in the ‘dark-laying’ strains than in the ‘light-laying’ ones. There was a positive correlation amongst four of the strains between degree of DDT-resistance and both mean oviposition time and oviposition period; the fifth, which combined long oviposition time with susceptibility to DDT, was a recently colonised West African strain.In small mass crosses between two strains differing markedly in mean oviposition time, this character showed no dominance; it appears to be under poly genie control. Evidence is given which indicates that there is no close genetic connection between oviposition time and DDT-resistance. There is also no obvious genetic association between oviposition time and ‘oviposition light preference’.It is concluded that the observed differences in oviposition time may have come about as a result of DDT selection, but could equally well have been the result of a selective influence exercised by the laboratory environment.


1970 ◽  
Vol 16 (1) ◽  
pp. 37-47 ◽  
Author(s):  
R. J. Wood

SUMMARYThe influence of the linkage group II locus y on DDT resistance in Aedes aegypti has been studied in crosses between the Trinidad resistant strain and QS susceptible strain. The y locus influences DDT resistance in both R/R and R/+ larvae. The effect of y may be interpreted as reducing the penetrance of R (RDDT1), which is also located on linkage group II. y+ is partially dominant and incompletely penetrant in its resistance-enhancing role (although in its pleiotropic effect on larval colour it is dominant and fully penetrant). Penetrance of y+ is influenced by an environmental factor, probably associated with the larval diet.The effect of y on resistance is evaluated in relation to other genetic influences on the expression of RDDT1.The significance of polymorphism at the y locus is discussed.


1975 ◽  
Vol 17 (4) ◽  
pp. 543-551 ◽  
Author(s):  
Judith M. Hitchen ◽  
R. J. Wood

The DDT resistance gene RDDT1, and the dieldrin resistance gene Rd1 have been mapped on linkage group II with respect to visible markers, in the mosquito Aedes aegypti L. The best interpretation of the data gives the order wa – Rd1 – ds – RDDT1 – s – y but wa – Rd1 – ds – y – s – RDDT1 is also possible, h is very loosely linked with RDDT1. The length of the linkage group has been considerably extended from previous studies.


1974 ◽  
Vol 16 (1) ◽  
pp. 177-182 ◽  
Author(s):  
Judith M. Hitchen ◽  
R. J. Wood

A genetical investigation of DDT resistance in Aedes aegypti has provided similar values of recombination between the gene for DDT resistance and visible markers, whether the response to DDT was scored as knockdown or as kill, indicating that resistance to knockdown and resistance to kill are controlled at the same gene locus.


Heredity ◽  
1975 ◽  
Vol 34 (1) ◽  
pp. 53-59 ◽  
Author(s):  
J P Margham ◽  
R J Wood

1970 ◽  
Vol 12 (3) ◽  
pp. 407-414 ◽  
Author(s):  
W. L. Lockhart ◽  
W. Klassen ◽  
A. W. A. Brown

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%.


1964 ◽  
Vol 96 (1-2) ◽  
pp. 100-101
Author(s):  
A. W. A. Brown ◽  
W. Klassen ◽  
M. K. K. Pillai ◽  
G. S. H. Hooper

This exhibit represents part of the work of the Department of Zoology in the past 5 years, and others who have contributed to it are F. Matsumura, Z. H. Abedi, T. Kimura, P. G. Fast, J. G. Towgood, J. N. Telford and N. H. Khan.The work with the mosquito Aedes aegypti has involved study of 8 susceptible strains. The mechanism of DDT-resistance has been found to be associated with its detoxication by an enzymic process of dehydrochlorination to DDE; the amount of DDE produced has been found to be directly proportional to the resistance level, both by experiments with larvae in vivo and with larval homogenates incubated with DDT and glutathione in vitro. A secondary resistance mechanism in American strains has been a very pronounced secretion and excretion of peritrophic membrane by the larvae.


1962 ◽  
Vol 4 (3) ◽  
pp. 319-332 ◽  
Author(s):  
A. W. A. Brown ◽  
Z. H. Abedi
Keyword(s):  

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