During genome engineering process, the role of flippase enzyme in the next round of modification in the
target gene is to
1. add frt sequence
2. remove frt sequence
3. remove the antibiotic cassette
4. add the antibiotic cassettd

Detailed Explanation:

The correct answer is: 2. remove frt sequence

Understanding Genome Engineering and the Role of Flippase Enzyme:

Genome engineering involves manipulating the DNA sequence within the genome of an organism to achieve desired traits or to study gene functions. One of the essential tools used in genome engineering is the flippase enzyme, which plays a critical role in modifying DNA.

In genome engineering, the flippase enzyme is used in a system known as the FLP/FRT recombination system. The FRT (Flippase Recognition Target) sequence is a short DNA sequence that can be recognized and cleaved by the flippase enzyme. The role of the flippase enzyme is pivotal for precise modifications in the target gene.

Functions of Flippase Enzyme:

1. Removal of FRT Sequence:
   The primary function of flippase in the context of genome engineering is to remove the FRT sequence from the DNA after it has been used to insert or modify a particular gene. This allows for precise genetic modifications without leaving extraneous sequences in the genome.

2. Antibiotic Cassette Removal:
   In many genome engineering procedures, an antibiotic resistance cassette (used for selection) is inserted into the genome. After the selection process is complete, the flippase enzyme can also be used to remove the antibiotic cassette, ensuring that the modification is free from unwanted resistance markers.

Why is the Flippase Enzyme Important?

The use of flippase allows for precise and clean genetic modifications. By removing the FRT sequence or antibiotic cassettes after the desired modification, researchers can ensure that the genome remains as close as possible to its original form, except for the intended modifications.

This method is widely used in various model organisms and has proven to be essential in creating knockout mice, generating stable cell lines, and other genetic research applications.

Conclusion:

In the context of genome engineering, flippase enzymes play an essential role by removing the FRT sequence and facilitating the removal of antibiotic cassettes. This ensures precise genetic modifications without leaving unnecessary sequences in the genome, thus improving the efficiency and accuracy of genetic experiments.