Assessing fitness costs for transgenic<i>Aedes aegypti</i>expressing the GFP marker and transposase genes

Irvin, Nic; Hoddle, Mark S.; O’Brochta, David A.; Carey, Bryan; Atkinson, Peter W.

doi:10.1073/pnas.0305511101

Cited by 122 publications

(108 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Catteruccia et al (6) found that Anopheles stephensi homozygous transgenic lines have lower fitness compared with WT, and Irvin et al (7) reached similar conclusions with transgenic lines of Aedes aegypti. However, these studies could not distinguish fitness effects due to the transgene itself versus insertion-site effects and/or inbreeding depression (8).…”

supporting

confidence: 51%

Transgenic malaria-resistant mosquitoes have a fitness advantage when feeding onPlasmodium-infected blood

Marrelli

Rasgon

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

107

View full text Add to dashboard Cite

The introduction of genes that impair Plasmodium development into mosquito populations is a strategy being considered for malaria control. The effect of the transgene on mosquito fitness is a crucial parameter influencing the success of this approach. We have previously shown that anopheline mosquitoes expressing the SM1 peptide in the midgut lumen are impaired for transmission of Plasmodium berghei. Moreover, the transgenic mosquitoes had no noticeable fitness load compared with nontransgenic mosquitoes when fed on noninfected mice. Here we show that when fed on mice infected with P. berghei, these transgenic mosquitoes are more fit (higher fecundity and lower mortality) than sibling nontransgenic mosquitoes. In cage experiments, transgenic mosquitoes gradually replaced nontransgenics when mosquitoes were maintained on mice infected with gametocyte-producing parasites (strain ANKA 2.34) but not when maintained on mice infected with gametocyte-deficient parasites (strain ANKA 2.33). These findings suggest that when feeding on Plasmodium-infected blood, transgenic malaria-resistant mosquitoes have a selective advantage over nontransgenic mosquitoes. This fitness advantage has important implications for devising malaria control strategies by means of genetic modification of mosquitoes. malaria control ͉ genetic modification ͉ gene drive T he use of genetically modified mosquitoes refractory to pathogen transmission is a potential strategy for controlling vector-borne diseases (1-4). In the past few years, important technical advances, including germ-line transformation of mosquitoes, the characterization of tissue-specific promoters, and the identification of molecules that interfere with parasite development (effector molecules), have led to the generation of transgenic mosquitoes that are impaired in their capacity to transmit the malaria parasite (1, 5). However, although the feasibility of genetically modifying mosquito vector competence has been demonstrated in the laboratory, we do not yet know how transgenes can be introgressed into mosquito populations in the field. Several possible approaches have been proposed (transposable elements, Wolbachia, and meiotic drive), but success of any mechanism will depend in part on the fitness load that is imposed by the presence of the transgene.Previous studies suggested that transgenic mosquitoes are less fit than wild type (WT) (6, 7). Catteruccia et al. (6) found that Anopheles stephensi homozygous transgenic lines have lower fitness compared with WT, and Irvin et al. (7) reached similar conclusions with transgenic lines of Aedes aegypti. However, these studies could not distinguish fitness effects due to the transgene itself versus insertion-site effects and/or inbreeding depression (8). In a separate study, Moreira et al. (2) demonstrated that hemizygous transgenic mosquitoes expressing the SM1 dodecapeptide under the control of the blood-inducible carboxypeptidase promoter were as fit as WT controls when fed on blood of noninfected mice.Plasmodium and other path...

show abstract

supporting

confidence: 51%

Transgenic malaria-resistant mosquitoes have a fitness advantage when feeding onPlasmodium-infected blood

Marrelli

Rasgon

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

107

View full text Add to dashboard Cite

show abstract

“…aegypti was assessed using a life-table approach (Irvin et al 2004). From mosquitoes that had been in colony since 1961, three lines homozygous for the transgenes were established and maintained for 2-3 years.…”

Section: Research On Gmm Fitnessmentioning

confidence: 99%

Fitness studies: developing a consensus methodology

Scott¹,

Rasgon²,

Black³

2006

Bridging Laboratory and Field Research for Genetic Control of Disease Vectors

View full text Add to dashboard Cite

In the near future, population biologists will be increasingly called upon to assess the potential of a large number of different genetically modified mosquito (GMM) strains to reduce pathogen transmission by natural mosquito populations. Adopting a standardized methodology for GMM fitness assessment will allow researchers to compare results from different laboratories and rapidly identify constructs and GMM strains that are most likely to be of applied use in the field. In this article we provide an operational definition for fitness, review the complexity of fitness, discuss lessons that can be learned from past genetic-based mosquito control programmes, and propose a methodology for rapidly and effectively assessing the fitness of GMMs compared to wild-type mosquitoes. Fitness is best understood as success at producing offspring. Because it can vary across identical genotypes, fitness is often considered as the average contribution to succeeding generations. Herein, we refer to the relative fitness of GMMs because they will be compared to their wild-type counterparts. Fitness is dynamic and measuring it is complicated. It can be influenced by variation in environment and genetic background. Based on conclusions from past mosquito population reduction projects, mating competitiveness and processes by which the size of populations are regulated will be important considerations for population replacement strategies. An examination of published results from fitness assessment of three transgenic mosquito lines indicates that to avoid the effects of inbreeding and fitness depression, transgenic lines should be outbred with wild-type strains before measuring fitness, and that transgenes may not necessarily confer a fitness cost. As a methodology for assessing GMM fitness we advocate three phases of cage competition experiments, beginning in the laboratory and ending in large field enclosures. For all three we recommend introgression of transgenes into the genetic background of the proposed target field population. Control cages should be included to assess common environmental effects. Relative fitness can be estimated from the frequency of transgene genotypes in subsequent generations. In the first phase, outbred GMMs would be introduced into laboratory cages at equal frequencies with 172 mosquitoes from the target field population. Phase two would be the same experiment, except that cages would be held at the proposed release site and GMMs would compete against mosquitoes collected directly from the field. In the third phase, mosquitoes would be released into large replicate outdoor enclosures and competed against field-collected conspecifics. The process would begin with many GMM candidate lines and end with one or very few lines that will be seriously considered for use in disease prevention.

show abstract

“…Furthermore, the small size (1.3 kb) of the 3xP3-EGFP marker provides an additional advantage, as it allows small transposon constructs resulting in high transformation rates (Horn et al, 2002). This transformation system has been applied to generate transgenic insects in different orders as Diptera, Hymenoptera, Lepidoptera and Coleoptera (Horn et al,2002;Lorenzen et al, 2003;Robinson et al, 2004;Irvin et al, 2004). Among the Drosophila species, D. willistoni stands out for possessing a great genetic variability and ecological versatility, being one of most studied of the family Drosophilidae.…”

Section: Introductionmentioning

confidence: 99%

“…This transposon is naturally found in the genomes of some lepidopteran (Cary et al, 1989). The piggyBac element was first used to transform the medfly, C. capitata (Handler et al, 1998), and more recently it has been used for transformation of many other species (Horn and Wimmer, 2000;Handler and McColombs, 2000;Handler, 2001;Horn et al, 2002;Atkinson, 2002;Robinson et al, 2004;Irvin et al, 2004). Other important component for the effective development of insect transformation technology is the use of genetic markers that allows recognition of the transformed individuals (O'Brochta and Atkinson, 1997).…”

Section: Introductionmentioning

confidence: 99%

“…The use of these methodologies is also being considered as a possible solution to certain medical and agricultural problems caused by some insects, through the cautious releasing in nature of insects with desirable genetic alterations (Kidwell and Wattam, 1998;Irvin et al, 2004). A widely method employed for insect germ-line transformation utilizes transposon-based vectors in a binary vector/helper system.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Genetic transformation of Drosophila willistoni using piggyBac transposon and GFP

Finokiet

Goñi

Loreto

2007

Braz. arch. biol. technol.

View full text Add to dashboard Cite

show abstract

Assessing fitness costs for transgenicAedes aegyptiexpressing the GFP marker and transposase genes

Cited by 122 publications

References 23 publications

Transgenic malaria-resistant mosquitoes have a fitness advantage when feeding onPlasmodium-infected blood

Transgenic malaria-resistant mosquitoes have a fitness advantage when feeding onPlasmodium-infected blood

Fitness studies: developing a consensus methodology

Genetic transformation of Drosophila willistoni using piggyBac transposon and GFP

Contact Info

Product

Resources

About