1,721,173 research outputs found
Insect Biotechnology: Controllable Replacement of Disease Vectors
No full textSummaryTo fight human vector-borne diseases, first releases of sterile transgenic mosquitoes have been performed. Someday, disease-refractory mosquitoes will replace wild types to stop transmission. For such population replacements, gene drive mechanisms must be established that allow local confinement and reversibility
Comparative analysis of binary expression systems for directed gene expression in transgenic insects
No full textBinary expression systems are of key interest to functional gene analysis by over-or misexpression. The application of such systems in diverse organisms would allow the study of many biological problems not addressable in model organisms. Here we report a set of constructs and an effective kinetic approach to quantitatively compare a series of diverse binary expression systems based on GAL4/UAS, LexA/(LL)4 and tetracycline-controlled tTA/TRE. By the use of these constructs, we could show that in Drosophila melanogaster the yeast-derived GAL4/UAS systems are more effective in activating responder gene expression than the bacterial-derived LexA/(LL)4 and tTA/TRE systems. The constructs are embedded in broad-range piggyBac-based transposon vectors and the transactivators are driven by the widely applicable 3xP3 promoter. These constructs should therefore be transferable to evaluate the functionality of binary expression systems in non-model insect species. (c) 2006 Elsevier Ltd. All rights reserved
Eco-friendly insect management
No full textGenetic engineering promises to improve a technique for controlling medflies that avoids chemical insecticides
Insect transgenesis by site-specific recombination
No full textTargeted genomic insertion wilt improve the qualitative and quantitative functional comparison of similar transgenes and provide suitable integration points for transgenes of applied interest
Transgenic technologies to induce sterility
No full textThe last few years have witnessed a considerable expansion in the number of tools available to perform molecular and genetic studies on the genome of Anopheles mosquitoes, the vectors of human malaria. As a consequence, knowledge of aspects of the biology of mosquitoes, such as immunity, reproduction and behaviour, that are relevant to their ability to transmit disease is rapidly increasing, and could be translated into concrete benefits for malaria control strategies. Amongst the most important scientific advances, the development of transgenic technologies for Anopheles mosquitoes provides a crucial opportunity to improve current vector control measures or design novel ones. In particular, the use of genetic modification of the mosquito genome could provide for a more effective deployment of the sterile insect technique (SIT) against vector populations in the field. Currently, SIT relies on the release of radiation sterilized males, which compete with wild males for mating with wild females. The induction of sterility in males through the genetic manipulation of the mosquito genome, already achieved in a number of other insect species, could eliminate the need for radiation and increase the efficiency of SIT-based strategies. This paper provides an overview of the mechanisms already in use for inducing sterility by transgenesis in Drosophila and other insects, and speculates on possible ways to apply similar approaches to Anopheles mosquitoes
Size relationships of different body parts in the three dipteran species Drosophila melanogaster, Ceratitis capitata and Musca domestica
No full textBody size is an integral feature of an organism that influences many aspects of life such as fecundity, life span and mating success. Size of individual organs and the entire body size represent quantitative traits with a large reaction norm, which are influenced by various environmental factors. In the model system Drosophila melanogaster, pupal size and adult traits, such as tibia and thorax length or wing size, accurately estimate the overall body size. However, it is unclear whether these traits can be used in other flies. Therefore, we studied changes in size of pupae and adult organs in response to different rearing temperatures and densities for D. melanogaster, Ceratitis capitata and Musca domestica. We confirm a clear sexual size dimorphism (SSD) for Drosophila and show that the SSD is less uniform in the other species. Moreover, the size response to changing growth conditions is sex dependent. Comparison of static and evolutionary allometries of the studied traits revealed that response to the same environmental variable is genotype specific but has similarities between species of the same order. We conclude that the value of adult traits as estimators of the absolute body size may differ among species and the use of a single trait may result in wrong assumptions. Therefore, we suggest using a body size coefficient computed from several individual measurements. Our data is of special importance for monitoring activities of natural populations of the three dipteran flies, since they are harmful species causing economical damage (Drosophila, Ceratitis) or transferring diseases (Musca)
Extensive sexual wing shape dimorphism in Drosophila melanogaster, Ceratitis capitata, and Musca domestica
No full textThe ability to powered flight facilitated a great evolutionary success of insects and allowed them to occupy various ecological niches. In addition to primary tasks, wings are often involved in various premating behaviors, such as courtship songs and initiation of mating in flight. These specific implications require certain wing morphology, size, and shape. Although wing properties have been extensively studied in Drosophila, a comprehensive understanding of sexual shape dimorphisms and developmental plasticity in wing morphology is missing for other Diptera. To acquire this knowledge, we applied geometric morphometrics and analyzed wing shape in three dipteran species (Drosophila, Ceratitis, and Musca) raised in different environmental conditions. We extensively studied sexual dimorphism and impact of sex and environment on the adult wing morphology. We present allometric and non-allometric shape differences between males and females and show that wing shape is influenced by rearing conditions in a sex dependent manner. We determine common trends in shape alterations and show that the anterior and posterior crossveins are likely to be plastic regions changing substantially at different environmental conditions. We discuss our data in the light of vein development and hypothesize that the observed shape differences might recapitulate different mating behaviors and flight capabilities
Molecular cloning and expression of nanos in the Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae)
No full textThe gene nanos (nos) is a maternal-effect gene that plays an important role in posterior patterning and germ cell development in early stage embryos. nos is known from several diverse insect species, but has so far not been described for any Tephritid fruit fly. Here, we report the molecular cloning and expression pattern of the nos orthologous gene, Ccnos, in the Mediterranean fruit fly Ceratitis capitata, which is a destructive pest of high agricultural importance. CcNOS contains 398 amino acids and has a C-terminal region with two conserved CCHC zinc-binding motifs known to be essential for NOS function. Transcripts of Ccnos were confirmed by in situ hybridization to be maternally-derived and localized to the posterior pole of early stage embryos. Regulatory regions of nos have been employed in genetic engineering in some dipterans such as Drosophila and mosquitoes. Given the similarity in spatial and temporal expression between Ccnos and nos orthologs from other dipterans, its regulatory regions will be valuable to generate additional genetic tools that can be applied for engineering purposes to improve the fight against this devastating pest. (C) 2013 Elsevier B.V. All rights reserved.German Academic Exchange Service (DAAD
Erratum to: Size relationships of different body parts in the three dipteran species Drosophila melanogaster, Ceratitis capitata and Musca domestica
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