Scientists create mice with 2 biological fathers
What's the story
In a groundbreaking study, scientists from China have successfully created mice with two biological fathers.
Though the achievement resulted in developmental abnormalities and sterility in the offspring, it could potentially help preserve critically endangered species.
The research was led by Zhi-Kun Li, a developmental biologist at the Chinese Academy of Sciences.
"This is a notable accomplishment in mammalian genetic engineering," Li told Reuters.
Methodology
CRISPR technology used to overcome genomic imprinting
To tackle the challenge of genomic imprinting, the research team employed CRISPR, a cutting-edge gene-editing tool.
This biological phenomenon makes sure that some genes are expressed differently depending on whether they are inherited from the mother or father.
To create mice with two fathers, scientists targeted 20 of these imprinted genes in male embryonic stem cells with CRISPR.
They then fused these edited cells with sperm and injected them into egg cells with removed nuclei.
Challenges
Offspring faced developmental challenges and sterility
The embryos were implanted into surrogate mothers, resulting in 134 pups. However, only 12% of the embryos survived to birth, and over half died before reaching adulthood.
The surviving mice were sterile, had craniofacial deformities, and exhibited behavioral abnormalities.
Guan-Zheng Luo, a co-author of the study said "The bipaternal mice exhibited developmental disorders."
Implications
Potential implications for conservation and genomic imprinting
Despite these challenges, the research could help conserve endangered species.
"This technique provides a potential method for producing offspring without relying on complex stem cell differentiation processes," said Li.
The study also sheds new light on genomic imprinting, with paternal genes promoting growth and maternal ones restraining it.
Kotaro Sasaki, a developmental biologist at University of Pennsylvania, not involved in the study, told MIT Tech Review, "This work helps us better understand the role of imprinting in development and reproduction."
Human application
Application in humans remains uncertain
The application of this research to humans is still unclear. Li said "Editing 20 imprinted genes in humans would not be acceptable."
Some experts argue that alternative and current family planning methods are more effective.
Martin Leeb, a stem cell biologist at the Max Perutz Labs Vienna, agreed saying "I can't imagine that these experiments could ever be replicated in humans."
But the Chinese team intends to expand their work to primates which are genetically closer to humans.