Team:GZHS-United/Demonstrate
Demonstrate
To demonstrate why our project will work in realistic condition, it is important to break our project into two different components and understand the functions of each components.
Our project can be divided into two parts: the protein part and the virus part.
As we are making a effective and environmental friendly mosquito killers, the two points that we will be looking at include the effect of mosquito control and its safety.
First, the protein we used to kill mosquito is Cry11Aa; Protein Cry11Aa is protoxin that is solubilized in the mosquito midgut. The Cry toxic fragment can bind to specific receptors located in the midgut epithelial cells. Oligomerization of the toxin that follows leads to membrane insertion, pore formation and cell lysis.
It should be emphasize that Cry11Aa will work only after the reaction happened in the mosquito midgut. Therefore, the characteristic of Cry11Aa is that it is highly-efficient and highly-specific.
According to research, Cry11Aa proteins are specifically toxic to mosquito larvae, harming neither plants nor mammals.
The utility of Cry11Aa is very promising. It shows high toxic to several kinds of mosquito including Aedes aegypti and Aedes albopictus, which are wildly spread mosquitoes which could spread diseases like dengue fever. Also, in compare to most insecticide and other protein in Cry family, there is less case of resistance found towards Cry11Aa.
Our virus part aims at producing recombinant virus which combines BmK IT (Buthus martensii Karsch insect toxin) and Aedes aegypti densovirus (AeDNV). BmK IT is a strong insect toxin from scorpion. It is an insect-selective neurotoxic polypeptide composed of 88 amino acid. It can affect insect neuronal sodium conductance by binding to excitable sodium channels. Then, the insect will be overexcited and died.
Aedes aegypti densoviruses (AeDNV) are small, single-stranded DNA viruses. These viruses are pathogenic to their hosts: they replicate in the nuclei of cells of mosquitoes and cause characteristic histopathological signs, which include hypertrophied, densely stained nuclei [3].
However, each of them will not work well if they are used separately. Using BmK IT to kill mosquito will be less sufficient if it is not acted inside the body. And the effect of AeDNV are usually slow. This is the reason why they have to combined in order to work well. We use the densovirus as a vector that can carry BmK IT specifically inside the mosquito and act in vivo.
There are a few things that make this combination realistic.
Firstly , the genome of AeDNV is relatively short, which makes the clone and transfection of foreign gene more convenience.
Secondly, after the transfection, the genome of AeDNV can release itself from the recombinant plasmid and replicate like the wild type virus does.
Thirdly, the gene segment of BmK IT is very short, which is only 267 bp. Therefore, it will not be a great burden for AeDNV when replicating.
Last but not least, the recombinant virus will be safe. First, AeDNV will infest only mosquitoes so that other kinds of animal won’t even be affected. Also BmK IT shows a high degree of neurotoxicity specifically toward insects and are safe for human beings and other animals.
