Q.Explain the role of Cry genes in genetically modified crops.

Cry genes from Bacillus thuringiensis let genetically modified crops manufacture their own insecticidal protein, protecting them from specific pests.

The soil bacterium Bacillus thuringiensis naturally produces crystal proteins encoded by cry genes (such as cryIAc and cryIIAb); these Cry proteins are toxic specifically to certain insect larvae because they bind to receptors present only in the gut lining of susceptible insects, causing gut-cell lysis and death of the larva, while being harmless to humans, livestock and most non-target organisms lacking these specific gut receptors. Scientists isolated these cry genes and introduced them into crop plants through genetic engineering -- Bt cotton, carrying cryIAc and cryIIAb genes, is the best-known Indian example, producing its own Cry toxin throu …