Practice question

Several recombinases perform site-specific DNA rearrangements. RecA mediates homologous recombination, not site specific excision. Flp recognizes FRT sites in yeast system analogous to Cre. Cas9 is RNA guided nuclease, not recombinase. Cre from bacteriophage P1 is widely used in eukaryotes for both deletion when loxP sites are directly repeated and inversion when oppositely oriented. Its ability to function without cofactors, high efficiency in mammalian nuclei, and reversibility control via mutant lox variants makes Cre preferred for conditional knockouts, lineage tracing and chromosome engineering.