The possibility of men in same-sex relationships and people who do not have their own eggs having biological children has been advanced by new research into in vitro gametogenesis, in which functional haploid gametes are generated from diploid somatic cells.

In previous, proof-of-principle experiments showing that haploidy in somatic cell genomes can be induced experimentally by premature cell division, the authors reported successful generation of haploid chromosomes from somatic cells using mature oocytes using an adapted somatic cell nuclear transfer (SCNT) technique. “Conventional SCNT produces diploid eggs that cannot be fertilized with sperm,” says principal investigator Shoukhrat Mitalipov, continuing, “Thus, we developed and added to the SCNT approach an experimental reductive cell division, which enables ploidy reduction in diploid somatic cells and production of haploid SCNT oocytes.” In this adapted SCNT approach, a somatic cell nucleus is transferred into an enucleated, metaphase meiosis II (MII)-arrested oocyte. Metaphase activity in these oocytes induces premature cell division, resulting in ploidy reduction in transplanted G0–G1 diploid somatic cell genomes by bypassing the S phase. In this SCNT approach, the somatic chromosomes have pseudo-meiotic spindles derived from the diploid G0–G1 somatic nucleus that are composed of two single chromatids, and these chromatids can be segregated at fertilization. On fertilization, somatic chromosome segregation into pseudo polar body 2 and a female pronucleus occurs, and the sperm genome forms a male pronucleus. The resulting mouse zygotes containing somatic and sperm pronuclei were able to develop into diploid blastocysts, embryonic stem cells and live offspring, but with very low efficacy. However, the mechanisms and factors influencing spindle organization and chromosome segregation in SCNT were unclear from these initial experiments.

体外配子发生的新研究提高了同性关系中的男性和没有自己卵子的人生出亲生孩子的可能性，其中功能性单倍体配子是由二倍体体细胞产生的。

在之前的原理验证实验中，作者报道了利用成熟卵母细胞利用适应性体细胞核移植（SCNT）技术从体细胞成功生成单倍体染色体。 “传统的 SCNT 产生的二倍体卵子不能与精子受精，”首席研究员 Shoukhrat Mitalipov 继续说道，“因此，我们开发了一种实验性细胞还原分裂方法，并将其添加到 SCNT 方法中，这使得二倍体体细胞的倍性减少并产生单倍体 SCNT 卵母细胞。”在这种改良的 SCNT 方法中，体细胞核被转移到去核的中期减数分裂 II (MII) 停滞的卵母细胞中。这些卵母细胞的中期活动会诱导细胞过早分裂，从而绕过 S 期，导致移植的 G0-G1 二倍体体细胞基因组的倍性减少。在这种 SCNT 方法中，体细胞染色体具有源自二倍体 G0-G1 体细胞核的假减数分裂纺锤体，这些纺锤体由两个单一染色单体组成，并且这些染色单体可以在受精时分离。受精时，体细胞染色体分离成伪极体 2 和雌性原核，精子基因组形成雄性原核。由此产生的含有体细胞和精子原核的小鼠受精卵能够发育成二倍体囊胚、胚胎干细胞和活的后代，但效率非常低。然而，从这些最初的实验来看，影响 SCNT 中纺锤体组织和染色体分离的机制和因素尚不清楚。