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Research Article
ScienceAsia 26 (2000) : 123-130 |doi: 10.2306/scienceasia1513-1874.2000.26.123
Biochemical Systematics and Isozyme Expression
in Insectiside Susceptible and Resistant
Anopheles albimanus Wiedemann Populations
Theeraphap Chareonviriyaphapa,* , Sylvie Manguinb, Donald R Robertsc and
Richard G Andrec
ABSTRACT: Isozymes of 6 test populations of Anopheles albimanus Wiedemann were compared using
starch gel electrophoresis. Tests were performed on laboratory colonies from El Salvador, Guatemala,
and Mexico, and 3 wild caught populations from Belize. From a total of 31 enzyme systems, 24 were
consistently detected and 35 putative loci were scorable. Higher genetic variability was found in the 3
wild caught populations from Belize and the young colonies (2 years in the laboratory) from Guatemala
and Mexico. Mean heterozygosity values of populations from Belize and the young colonies from
Guatemala and Mexico ranged from 0.093 to 0.200, compared with 0.057 of the old colony (20 years in
laboratory) from El Salvador. Detailed analyses showed all 6 populations of An. albimanus to be conspecific
with minor instraspecific variations. Zymograms were compared among 6 test populations of An. albimanus, including a pyrethroid resistant colony from Guatemala (El Salvador). One locus of esterase,
Est-3, was found to be diagnostic for separating susceptible and resistant populations. Since esterase
was consistently elevated in the resistant population, we conclude that esterase may be specifically
involved in the metabolic detoxification pathway in a pyrethroid resistant population. Due to regular
agricultural use of organophosphate and carbamate insecticides in Guatemala, the elevated esterase
activity in El Semillero colony also may be associated with these 2 compounds. Therefore, the elevated
esterases in wild An. albimanus populations may be related to the exposure to organophosphate, carbamate,
pyrethroids, or all 3 compounds, and may limit insecticide use against An. albimanus populations in
parts of Central America.
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a Division of Biology, Faculty of Liberal Arts and Science, Kasetsart University, Kamphangsaen Campus, Nakhon Pathom 73140, Thailand.
b CR1 LIN, IRD 911 Ave Agropolis. BP 504534032 Montpellier Cedex 1. France.
c Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda, MD. 20814-4799.
* Corresponding author E-mail: faasthc@nontri.ku.ac.th
Received 4 Jan 2000, Accepted 6 Jun 2000
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