TLS Online TPP Program

#Id: 6168

#Unit 12. Applied Biology

Cry proteins divided into four main groups or first ranks, viz., Cryl, Cry II, CryIII and CryIV, on the basis of their insecticidal activities.

TLS Online TPP Program

#Id: 6169

#Unit 12. Applied Biology

The commercial Bt–cotton available today contain genes from the isolate B-thuringiensis, ssp. that produces Cry I A(a), Cry I A(b), Cry I A(c), Cry IIA.

TLS Online TPP Program

#Id: 6170

#Unit 12. Applied Biology

The Cry proteins are solubilized in the alkaline environment of insect midgut and are then proteolytically processed to yield a toxic core fragment.

TLS Online TPP Program

#Id: 6171

#Unit 12. Applied Biology

The toxin fragments of Cry proteins have 3 domains: 

Domain, I functions in pore and ion channel formations, 

Domain II is involved in receptor recognition, 

Domain III binds the receptor and affects channel properties. The toxin fragments arc believed to bind to specific high-affinity receptors present in the brush border of midgut epithelial cells

TLS Online TPP Program

#Id: 6172

#Unit 12. Applied Biology

TLS Online TPP Program

#Id: 6173

#Unit 12. Applied Biology

Cry proteins, in general, have no adverse effects on higher animals, including mammals since, there are no specific receptors in the gastrointestinal tracts of mammals.