With stem cells and #CRISPR, scientists breed mice with same-sex parents
Mammals still need both sets, though, to have their full suite of genetic instructions. IGF2, for example, is a gene crucial for growth and development, but only the paternal copy is normally active. If we just inherited DNA maternally then, we wouldn’t grow or develop properly; that gene would simply remain off. On the flip side, there are a number of these genes for which we rely on our mothers.
But scientists started challenging nature’s way a decade and a half ago. The trick was to cajole certain maternal genes to act like paternal genes in terms of their activity, or vice versa.