In the described cloning process, what is the purpose of including a sheep promoter in front of the Factor IX gene?

• A. To drive expression of the human Factor IX gene in sheep cells
• B. To allow jellyfish gene to glow
• C. To protect the gene from degradation
• D. To assist replication of plasmid

Answer: (A)

Promoters act as the switches that tell cells where transcription should start. A sheep promoter placed in front of the human Factor IX gene ensures that the sheep’s cellular machinery can recognize and initiate transcription of that gene in sheep cells. That means mRNA for Factor IX is produced, which is then translated into the Factor IX protein in the animal. Without a promoter that the host species can use, the gene wouldn’t be transcribed and no protein would be made.

This isn’t about making proteins glow (that would involve a different gene and its own promoter) or about protecting the gene from degradation, or about helping the plasmid replicate. The promoter’s role here is to drive transcription in the sheep.