Basic genetics: what would YY be?

Question

If the combination XX is female, and the combination XY is male, what - if anything - would result from a YY combination?

Answer 1

ok. i have an idea and a question to go with it.

it is known that artificial fertilization is possible in a lab, such as done when a mother can't carry the baby in her womb for some reason. it is also possible, with today's advancement in cloning, to remove all genetic material from and egg and implant it with new genetic material.

thus,

if we took the genetic material from a male and implanted it into a "clean" egg and then fertilized it with male sperm the following THEORETICAL combinations are possible:
XY + XY  =  XX, XY, XY, YY

in conclusion, it is indeed theoretically possible to allow such parring.
HOWEVER, it begs the question of do we really know enough about the Y chromosome to unequivocally rule out that such a baby can successfully develop? and if it is at all, even remotely possible, then what would be its characteristics?