Provide two explanations for how telomerestelomerase modulat

Provide two explanations for how telomeres/telomerase modulate the aging process and discuss a disease that involves premature aging.

Solution

Telomeres are repetitive DNA sequences present at the ends of chromosomes. Telomerase is a ribonucleoprotein, RNA based DNA polymerase that maintains telomere length. Telomerase consists of reverse transcriptase action. It has its own RNA, against which it synthesizes DNA at the ends of chromosomes to maintain the integrity of chromosomes.

In the absence of telomerase, telomeres progressively shorten. Shortening of telomeres limits the growth of cells, either by senescence, in cells with intact cell-cycle checkpoints (such as G1 arrest), or by crisis in cells with inactivated checkpoints (telomerase end to end fusion causes breakage of chromosomes and mitotic catastrophe).

A recent study proved that reactivation of telomerase enzymes resulted in reversing the aging process and regaining the fertility. However, excess production of telomerases would result in cancer.

Dyskeratosis congentia (DC) is a rare disease that is caused mainly due to inhibition of telomerase at an early stage that resulted in premature aging.