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Identifier

000412868

Title

In vivo λειτουργική αξιολόγηση σημειακών μεταλλαγών ανθεκτικότητας στόχου οι οποίες έχουν βρεθεί στα είδη Aedes aegypti και Tetranychus urticae

Alternative Title

In vivo functional validation of target site resistance mutations identified in Aedes aegypti and Tetranychus urticae species

Author

Χρήστου, Ιάσων Κωνσταντίνος

Author

Βόντας, Ιωάννης

Reviewer

Δελιδάκης, Χρήστος
Χαλεπάκης, Γεώργιος

Abstract

Resistance to insecticides is a long-term and staggering global threat directly affecting the health and agricultural sectors as it poses a significant obstacle to effective control of harmful insects. The long-term and frequent use of insecticides has exacerbated the frequency of resistance, with more than 550 resistant insect and mite species being recorded so far. Understanding insecticide resistance mechanisms is essential to further develop tools and interventions that can improve pest control. One of the main mechanisms of insect resistance is target site resistance resulting from mutations in the target molecule of the insecticide. Drosophila melanogaster, although not a harmful species, has been extensively used as an experimental model in research to understand insecticide resistance mechanisms. The first part of this thesis focuses on the study of the role of the point mutation V1016G found in resistant populations of Aedes aegypti, a major disease vector. With the usage of CRISPR/Cas system and a series of successive crosses, Drosophila melanogaster homozygous strains were constructed with the V1016G mutation. Bioassays with the insecticide deltamethrin were then performed on wild-type and homozygous mutants (V1016G). The results show that the presence of the V1016G mutation in the voltage-gated sodium channel renders the mutant strains up to 25 times more resistant to deltamethrin. The second section concerns the mutations G323D and G326E found in resistant populations of Tetranychus urticae. This mite affects a large variety of plants and is characterized as one of the most insecticide resistant organisms in the world. These two mutations are found in two of the five T. urticae GluCl genes, GluCl1 and GluCl3, and share the same genomic position as the D. melanogaster orthologue DrosGluClalpha. This chapter consists of two independent experiments. The first of concerns the construction of homozygous strains with the G323D mutation and the second the construction of homozygous strains with the G326E mutation. In the crossing process, both strains were unable to carry the mutation in a homozygous state. Chapters D.B.1 and D.B.2 analyze the possible causes that may underpin the lethality as well as future experimental directions which could be pursued in order to study the nature of these mutations.

Language

Greek

Subject

CRISPR/CAS

Dunge fever vector

Genetic modification-engineering

Insecticide resistance

KDR mutations

Molecular entomology

SNPS

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