Insect Control Flashcards
What are the key potential outcomes of transmission-blocking vaccines for the target organism?
reduced fecundity
reduced lifespan
prevent parasite transmission to vector
What is a transmission-blocking vaccine?
- a vaccination against a vector protein or parasite protein.
What is required for the development of a transmission-blocking vaccine?
target organism target gene(s)/replacement gene gene regulatory elements selection mechanism reporter or marker mechanism for DNA insertion/alteration mechanism to drive transgene into a population
Types of release (of GM insects)
Pre-control - suppress existing vector pop. with insecticide before release of GM vectors
Inundative - choose time & place where released GM vectors are competitive with wild type.
Example of a target organism
Anopheles or Aedes mosquitoes
Target gene or replacement gene
Physical acquisition of the gene:
Once identified, the gene of interest can be amplified (PCR), either by using gDNA or cDNA (synthesised using mRNA)
cDNA is best as it does not contain introns
What is a gene regulatory element?
Only 15% of genes are expressed at any given time
Transcription factors (TFs) are gene regulatory proteins that control protein expression of other proteins – can repress or activate expression
Operators can repress expression and are stretches of DNA to which TFs bind
Molecular approaches to control disease transmission in insects
Transmission blocking vaccines
Example of a successful GM reporter or marker
Green Fluorescent Pigment (GFP)
Mechanism for DNA insertion/alteration
Vertical Transmission: transfer from parent to offspring
Horizontal Transmission: transfer of genetic information to non-offspring organisms (rare)
Mechanism to drive a transgene into a population
Sterile Insect Technique (SIT)
(Release of Insects Carrying Dominant Lethal) RIDL
Techniques used in genetic engineering
Transgenics
CRISPR
Techniques used in genetic engineering
Transgenics
CRISPR
What is the importance of GSM (genetic sexing mechanisms)?
There are problems related to releasing female insects i.e. even if non-disease carriers, they bite people, so we want to select for males
Release of male and female together may lead to poor dispersal (they will stay in one place and mate). So, may want to select for males…
What is the tTAV-tetO system?
tTSV = Tetracycline-controlled transactivator tetO = tetracycline operator
