1.   These may be transferred to the next generation when individual reproductive cells have been manipulated.

2.   An exception is cells in the testes and ovaries, which have active telomerase because reproductive cells must keep dividing.

3.   Exceptions are reproductive cells and cancer cells.

4.   Only reproductive cells, eggs and sperm, produce telomerase.

5.   Virtually all types of body cells, except reproductive cells, contain an aging clock.

6.   While far from perfected, the technique of piggybacking ovarian tissue on another species could provide a way to generate female reproductive cells for endangered species in breeding programs.

7.   In earlier research, however, Shay and others found that some cancer cells and reproductive cells release an enzyme called telomerase that keeps the telomere from shortening.

8.   Previously, most cloning experiments ranging from mice to Dolly the Sheep used DNA extracted from female reproductive cells.

9.   Lactoferrin devours iron, depriving the bacteria of an essential nutrient and forcing them to wander across the surface for a new home instead of forming reproductive cell clusters.