What the new study revealed is that various binary combinations and doses of Bt toxins
target mammalian cells, particularly the erythroid (red blood cell) lineage, resulting in white and red blood cell changes indicative of significant damage.
Insect resistance to Bt toxins
in GM insect resistant crops.
Furthermore, as Bt cotton plants age, toxin concentrations decline, which could increase survival of pests that have inherently low susceptibility to Bt toxins
(Carriere et al., 2010; Brevault et al., 2012).
'The technology not only enabled us to knock out and validate a receptor for Bt toxins
used in insect controls, we were also able to demonstrate that the CRISPR-Cas9 technique can act as a powerful and efficient genome editing tool to study gene function in a global agricultural pest.'
The genomic DNA will be used to prepare high-throughput genome sequencing libraries for targeted enrichment of genetic loci associated with resistance to Bacillus thruringiensis crystalline toxins (Bt toxins
) Cry1Ac and Cry2Ab as well as receptors for all major classes of insecticides.
Nutrition affects insect susceptibility to Bt toxins
. Scientific Reports 7: 39705.
Truncated forms of the genes that code for Bt toxins
have been genetically engineered into plants.
Strains of this bacterium produce over 200 different Bt toxins
, each harmful to different insects.
produce insecticidal toxins with oral toxicity similar to that of Bt toxins
, but have not yet been fully utilized.
get adhered to specific binding sites in insect's midgut lining where they unsettle the cytoplasmic membranes making the way to cell lysis.
Monsanto downplayed the findings, saying that Bt toxins
are "inoffensive and break down in the digestive tract." Lead scientist Marcia Ishii-Eiteman of the Pesticide Action Network North America (PANNA) is not so sure.
US government agencies consider the Bt proteins produced by genetically modified (GM) crops to be the same as natural Bt toxins
. However, toxins produced by GM crops " ...