What is a transgenic mouse?

What is a transgenic mouse?

• A. A mouse that has DNA from a different source in its genes.
• B. A mouse that had DNA removed or disabled in its genes.
• C. A mouse that differs from another strain by one gene.
• D. A mouse with the genetic makeup of two strains.

Answer: (A)

Introducing foreign DNA into the genome to create a transgenic organism. In a transgenic mouse, DNA from a different source (such as a human gene or a reporter gene) is stably integrated and inherited, allowing researchers to study how that gene functions in the mouse model under a chosen promoter. This is different from removing or disabling a gene, which creates a knockout and changes function by loss rather than addition. It also differs from simply having a difference by one gene between strains, which reflects natural genetic variation rather than deliberate foreign DNA insertion. Likewise, having the genetic makeup of two strains describes crossing or combining backgrounds, not inserting new DNA. The defining feature is the presence of foreign DNA incorporated into the genome that is passed on to future generations.

Introducing foreign DNA into the genome to create a transgenic organism. In a transgenic mouse, DNA from a different source (such as a human gene or a reporter gene) is stably integrated and inherited, allowing researchers to study how that gene functions in the mouse model under a chosen promoter. This is different from removing or disabling a gene, which creates a knockout and changes function by loss rather than addition. It also differs from simply having a difference by one gene between strains, which reflects natural genetic variation rather than deliberate foreign DNA insertion. Likewise, having the genetic makeup of two strains describes crossing or combining backgrounds, not inserting new DNA. The defining feature is the presence of foreign DNA incorporated into the genome that is passed on to future generations.