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

Hint: 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.