SRY gene is sex-determining region on the Y chromosome. SRY is essential for maleness. If it is inactivated, the progeny will develop as a female although it has a Y chromosome.
So, the progeny produced by a sperm with inactivated SRY gene, the phenotype will be female although it has a Y chromosome.
The mice, which are produced by a sperm with inactivated SRY gene, will be female in its phenotype. But on the genotype it may be XX and XY. Thus, XY will be sterile and look like females.