As a science fiction fan and ardent futurist, recent work coming out of Japan and what it could mean for gay couples, infertile people and the future of in vitro fertilization (IVF) has me feeling full of wonder.
Though, for the sake of realism, it’s important to note this work is just that, a future prospect.
That doesn’t make it any less incredible that Japanese molecular biologists Drs. Mitinori Saitou and Katsuhiko Hayashi of Kyoto University have started on a path that could, according to them, viably build an egg from human skin cells, creating the possibility of two men birthing a child with genetic material exclusively from the couple, among many other variations the technology could create.
The idea inspires imaginings of a future where couples of any kind, especially gay, transgender and infertile people, could reproduce together, passing on their own traits, free from the shackles of exclusively dichotomous female-egg with male-sperm. The scientific development, as so often is the case, starts with mice.
For those who want to understand their work, I am going to do my best to break it down as simply as possible from a fantastic and thorough Nature article, which explains the Doctors’ work in depth.
We’ll start with the creation of typical sperm and eggs. A germ cell is a biological cell that migrates to developing gonads, the inner workings of the human reproductive system and, through cell division and cellular differentiation, when cells take on more specialized types, eventually become mature gametes, the sperm or eggs.
For mice, these germ cells come about after the first week of embryonic development as a few dozen primordial germ cells (PGCs), which would go on to be the eggs and sperm mice have at birth. These PGCs are the very basic of material that pass on a mouse’s genetic heritage. From the skin cells of mice in vitro, Hayashi was able to create PGCs.
With years of work on molecular biology between them, Hayashi and Saitou worked together, inserting PGCs into the testes of mice that couldn’t produce their own sperm. These developed into viable sperm which, when coupled with an egg, the embryo inserted into a female resulted in fertile male and female mice.
The next step was to create sperm through induced pluripotent stem cells, basically turning adult cells into an embryo-like state. The sperm cells worked, this scientific achievement called “a rare accomplishment,” but eggs were expected to be more difficult.
Hayashi created PGCs in vitro, making those very basic cells that normally transform into eggs or sperm within mice, from the cells of a normal-coloured mouse. He put those PGCs into the ovaries of an albino female, and the eggs, fertilized in vitro, grew into albino pups.
The science is essentially, take the PGCs from skin cells, like those that are found within embryonic stem cells, insert these into the place where they would normally develop into eggs or sperm, and let nature take its course.
Hayashi has already been receiving a number of requests from prospective parents, but he warns them that a viable human treatment could be decades away. “My impression is that it is very far away,” he says. “I don't want to give people unfeasible hope.”
There are a number of other long-term technical and ethical concerns that have scientists, including Saitou, urging caution, and they’ve explained that working on the human option would be basically starting from scratch.
However, with no stretch of the imagination for humans, this has a great future prospect for same-sex parents, or couples with a transgender parent. This means you could take the PGCs from the skin cells of a human male — for instance, a gay man — transfer them into the ovaries of a female, and let them create their own eggs with the male’s genetic material. These eggs could then be fertilized in vitro by the sperm of the gay man’s partner, birthed by a surrogate, and the child would have all of the genetic material from the two parents.
Not a very sexy process as far as making babies, but a very big, sexy scientific leap forward!