By my understanding, this research has identified a small number of epigenetically regulated genes that affect the ability of two haploid sets to combine into a

By my understanding, this research has identified a small number of epigenetically regulated genes that affect the ability of two haploid sets to combine into a viable zygote. The researchers proved their effect by knocking them out, probably with a CRISPR/Cas9-like deactivation complex. Future developments will have to instead epigenetically de-regulate and artificially re-regulate those target genes in order to produce a healthy adult organism. They may eventually be able to make the haploid set from a stem cell masquerade as either the set from an egg or the set from a sperm, as required.