These resultant haploidcells can fuse with other haploidcells of the opposite sex or mating type during fertilization to create a new diploid cell, or zygote.
Here we used genome - saturated mutagenesis to create a biobank of over 100,000 individual haploid mouse embryonic stem (mES) cell lines targeting 16,970 genes with genetically barcoded, conditional and reversible mutations.