Q. With reference to Site-Directed Nuclease (SDN), consider the following statements;
1.SDN 1 introduces changes in the host genome’s DNA through small insertions/deletions without the introduction of foreign genetic material.
2.SDN 2 involves larger DNA elements or full-length genes of foreign origin which makes it similar to Genetically Modified Organisms (GMO) development.
Which of the statements given above is/are correct?

[A] 1 only

[B] 2 only

[C] .Both 1 and 2

[D] .Neither 1 nor 2

Answer: A
Notes:

Depending on the nature of the genome editing that is carried out, the process is divided into three categories — Site-Directed Nuclease(SDN 1), SDN 2 and SDN 3:

Statement 1 is correctSDN 1 introduces changes in the host genome’s DNA through small insertions/deletions without the introduction of foreign genetic material.

Statement 2 is incorrect: In SDN 2, the edit involves using a small DNA template to generate specific changes. Both these processes do not involve alien genetic material and the end result is indistinguishable from conventionally bred crop varieties.

The SDN3 process involves larger DNA elements or full-length genes of foreign origin which makes it similar to Genetically Modified Organisms (GMO) development.

Source: Notification of Standard Operating Procedures(SOPs) for regulatory review of Genome Edited Plants under SDN-1 and SDN-2 categories, 2022