Final answer:
Knock-out mice experiments with no telomerase involve the use of mice that are deficient in telomerase, an enzyme responsible for the maintenance and extension of telomeres. Reactivation of telomerase in these mice has shown positive effects in reversing tissue degeneration and improving organ function.
Step-by-step explanation:
Knock-out mice experiments with no telomerase involve the use of mice that are deficient in telomerase, an enzyme responsible for the maintenance and extension of telomeres, which are protective caps at the ends of chromosomes. Telomerase-deficient mice exhibit tissue atrophy, stem cell depletion, organ system failure, and impaired tissue injury responses. The reactivation of telomerase in these mice has shown to extend telomeres, reduce DNA damage, reverse neurodegeneration, and improve organ function.