Question

The anticoagulant hirudin is obtained from:
(a) Ti plasmid of Agrobacterium
(b) Bt toxin produced by cry gene
(c) Seeds of Brassica napus
(d) None of the above

Answer 1

The anticoagulant hirudin was previously obtained from blood-sucking leeches. However, due to the low output, there are various ways where other organisms can be transgenically modified to produce hirudin instead.

Complete step by step answer:
- Hirudin is an anticoagulant produced in the salivary glands of the blood-sucking leeches.
- The substance has a high affinity for thrombin and is its inhibitor, hence it is used for research and therapeutic purposes.
- It can be difficult to extract large amounts of hirudin from leeches alone, hence recombinant technology to create transgenic species that produce hirudin is created.
- Brassica napus or the rapeseed plant is a candidate for the production of hirudin. It is genetically modified such that its seeds produce hirudin in large quantities.
So, the correct answer is ‘Seeds of Brassica napus ’.

Additional Information:
- The Ti plasmid of Agrobacterium has wide applications in genetic transformations in plant cells.
- The Bt toxin produced by the cry gene has been expressed in multiple plants and crops as this is a pesticide preventing pests like the bollworm. Bt toxin has been expressed in cotton and brinjal. The Bt stands for Bacillus thuringiensis.
- The technique used for the production of proteins in oilseeds is called oleosin partitioning.

Note:
- The blood-sucking leeches used for medical procedures are known as medical leeches. An example of them is Hirudo medicinalis.
- The leeches puncture the vein of the host and then produce the anticoagulant. The puncturing process is known as phlebotomy.
- Hirudin and its analogs are being considered as better therapeutic options over heparin, another commonly used blood anticoagulant.