Four types of anchoring junctions are present in cells:

1. Adherens junctions

2. Desmosomes

3. Hemidesmosomes

4. Focal adhesions

TLS Online TPP Program

#Id: 6166

#Unit 12. Applied Biology

B. thuringiensis is a spore forming bacterium, which produces a crystal protein as parasporic inclusion in the vegetative cell containing the spore.

TLS Online TPP Program

#Id: 6167

#Unit 12. Applied Biology

The cry gene of B. thuringiensis produces a protein, which forms crystalline inclusions in the bacterial spores. These crystal proteins are responsible for the insecticidal activities of the bacterial strains.

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.

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#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.

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#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