A mammal needs fertilized egg cells to have children, right? Not so fast. University of Bath scientists report that they're the first to successfully breed healthy mice without any fertilized eggs, instead relying on inactive embryos. The team first doused eggs in strontium chloride, which prevents them from going into a state of arrest while they're turned into embryos -- previous attempts to fool the eggs saw them die within a few days. Researchers then inserted sperm nuclei that reprogrammed the embryos, readying them for the wombs of their surrogate mothers.
The university isn't sure exactly how the reprogramming works, so there's still plenty to discover. Also, there's no certainty that you'd see the same result in humans. It's probable but not guaranteed, lead researcher Tony Perry explains to Gizmodo.
At a minimum, this is a breakthrough for our understanding of mammalian reproduction: it demonstrates that sperm don't need an egg to mature and create a living child. However, it also has far-reaching implications for human reproduction. Gay men wanting children would only need women as surrogate mothers, and couples could sometimes overcome seemingly intractable infertility issues. Assuming technology permits this in humans in the first place, society may need to hold an ethical debate to decide whether or not it wants children conceived without conventional fertilization.