In a groundbreaking development, scientists in China have unveiled a novel method for breeding baby mice with two male parents. This innovative approach not only allows the offspring to survive to adulthood but also provides fresh insights into a complex suite of genes that exhibit variable activity based on the parent of origin. The study, published in the journal Cell Stem Cell, marks a significant milestone in genetic research and builds upon previous work conducted in Japan.
Researchers in China have successfully bred mice using skin cells from adult male mice, transforming these cells into stem cells capable of developing into eggs. This process involves injecting these embryonic stem cells, along with sperm from a male mouse, into a second egg. To address challenges related to placental development—a critical hurdle in such reproductive experiments—scientists introduced 20 strategic genetic modifications into the DNA of the stem cells.
"Our approach directly targets imprinted genes, which have long been suspected to play a central role in bi-paternal reproductive barriers," stated Zhi-kun Li.
The research builds on earlier work by scientists in Japan, who achieved similar results by transforming skin cells into stem cells. The resultant mice from both studies managed to survive to adulthood, although they displayed deficits such as shorter lifespans compared to typical mice. This ongoing research explores the intricate activity of imprinted genes and their influence on offspring viability based on parental origin.
"It is somewhat surprising that manipulation of only 20 imprinting genes allows relatively normal development of bi-paternal embryos where there are hundreds of imprinting loci in mice," remarked Kotaro Sasaki.
The new method not only provides insight into genetic imprinting but also holds potential for broader applications. Imprinting disorders—genetic conditions caused by anomalies in the expression of imprinted genes—could eventually benefit from such pioneering techniques. By understanding these genetic mechanisms, researchers aim to pave the way for innovative treatments using gene editing technologies.
In past experiments conducted in Japan, scientists faced challenges with placental growth during pregnancy, although the offspring fared better post-birth. The recent advances by Chinese scientists highlight an alternative approach that achieves similar outcomes, yet still requires refinement to address observed developmental deficits.
"This is another significant step forward in understanding the biology of imprinting," stated Keith Latham, underscoring the importance of these findings in advancing genetic research.
The long-term objective of this research is to deepen scientific understanding of imprinting disorders and potentially develop gene editing solutions to correct these anomalies in humans. As scientists continue to unravel the complexities of genetic imprinting, the possibilities for future medical breakthroughs remain vast.
Virginijus Šikšnys noted that this research "will provide cures for genetic diseases that were incurable before."
