All ETDs from UAB

Advisory Committee Chair

Maria D Luca

Advisory Committee Members

Asim K Bej

Pauline E Jolly

Douglas R Watson

Stephen A Watts

Document Type

Dissertation

Date of Award

2013

Degree Name by School

Doctor of Philosophy (PhD) College of Arts and Sciences

Abstract

Widespread use of pyrethroids for control of malaria vectors together with use in agriculture for pest control has led to an increase in emergence of populations of pyrethroid resistant phenotypes. Insecticide resistance can likely alter vector development time, reproduction, behavior, and longevity, all of which can affect the potential for disease transmission. In this study we assessed whether the genetic modifications (kdr mutation, cytochrome P450 and esterase detoxification) in a permethrin resistant strain of An. gambiae influence traits related to fitness. The performances of these traits were compared between two strains of An. gambiae, one permethrin susceptible (ASEMBO1) and the other permethrin resistant (RSP) when held under identical conditions. First we assessed several life history traits and energy metabolism traits in females. We found that the RSP larvae had a longer developmental time, but a reduced normal lifespan compared to the ASEMBO1 strain. We also measured metabolic rate and mitochondrial ROS production and found that RSP adult females had reduced metabolic rate and mitochondrial coupling efficiency but higher mitochondrial ROS production. Temperature is an important abiotic factor which influences mosquito life cycle. Next, we compared develop-mental time from L1 to adult emergence and adult body size between the two strains cultured at 25C or 30C. Both strains showed reduced survivorship at 30C. RSP had a longer mean developmental time than ASEMBO1 strain. The mean dry weight was significantly lower in mosquitoes cultured at 30C than at 25C. Lastly, we assessed the effect of temperature on glycogen utilization to understand effects of rearing temperature on survival strategies between the two strains. Glycogen content was measured in teneral adults and in adults reared at 25C or 30C and exposed to two nutritional states (honey-fed or starved). Glycogen content in teneral adults fed and in starved adults was significantly higher in the RSP strain than in the ASEMBO1 strain. Under starvation conditions, the RSP strain lived significantly longer than the ASEMBO1 strains at both 25C and 30C. This dissertation provides the first insights into life history and energy metabolism traits in An. gambiae with co-occurrence of kdr mutation and metabolic detoxification mechanisms.

Share

COinS