[something098]

Both eggs and sperm producing cells are created during formation of embrio. We could even define that these cells as "clones of you" that were created not much after your first cells were created, because your DNA, that undergoes changes in your organism is never given to your offsprings - it is DNA of your "clone" cells. Eggs are as you have defined - "very old cells". Most probably cells that are producing sperm also can be defined as "very old cells" as most probably sperm production does not function the same way as other cells, that are staying in organism and accumulate mutations.

Stem cells from other organs has absolutelly nothing to do with this. Unless you are refering to procedures of planting stem cells from one organ to another to help failing organ, as stem cells are universal cells, that are able to produce cells for any organ.