Final answer:
In recombinant DNA construction, the GFP gene's coding region can be deleted, inverted, replaced, or amplified. The procedure and subsequent modifications play a critical role in gene expression and the study of protein production. Specific libraries constructed from mRNA highlight expressed genes, enabling targeted research.
Step-by-step explanation:
Understanding Recombinant DNA and Gene Expression
When constructing recombinant DNA, a foreign DNA fragment is inserted into a plasmid vector. This process can lead to different outcomes depending on the manipulation of the DNA sequence. Specifically,
- If the coding region of the GFP gene is deleted, it means the gene has been removed from the DNA sequence.
- If it is inverted, the gene sequence is reversed within the DNA.
- If it is replaced, another DNA sequence has taken the place of the GFP gene.
- If it is amplified, the number of copies of the gene within the DNA is increased.
DNA must be treated to express silenced genes, as seen with the demethylated and acetylated forms. For transcription testing, genes are altered, showing varying levels (++), (+), and (+++) representing normal, low, and high transcription levels, respectively. Researchers can identify, clone, and sequence foreign DNA in recombinant colonies to verify protein expression. Constructing libraries from mRNA, as opposed to genomic DNA, allows focus on expressed genes, excluding intronic and other non-coding regions.