Mariposa Super Mutants have genders, the whole reason the Master's plan would have failed was because female Super Mutants were barren. Vault 87 Super Mutants are apparently asixual, but Super Mutants on the west coast retain their primary sixual characteristics.
I could have swore that master's plan would have failed because there was no genders. I thought It didn't matter if the subject was male or female they still turn out the same and there is no way to distinguish if they are male or female after they are turned into a super mutants. I really don't remember anything mentioning they keep their primary sixual characteristics until new Vegas came out...
Well I do know for a fact is that they were dipping people in the FEV because they have no way of reproducing in fallout 1. Genders or no genders they have no way of reproducing without exposing people to FEV.
I could be wrong but that's how I remembered it...