Scientists Create Mice wiht two Fathers, Paving the Way for Groundbreaking Genetic Research
In a groundbreaking achievement, researchers from the Chinese Academy of Sciences in Beijing have successfully conceived mice with “two fathers” that survived to adulthood. Published in the journal Cell Stem Cell, this study marks a significant milestone in genetic research and opens the door to potential applications in primates and beyond.
The Role of Genomic imprinting
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At the heart of this breakthrough lies the concept of genomic imprinting. Certain genes, known as “imprint genes,” are expressed differently depending on whether they are inherited from the mother or the father. For healthy embryonic progress,animals require a balanced “dose” of these genes from both parents. Without this balance, gene expression can become deregulated, leading to developmental anomalies.
To overcome this biological hurdle, the team targeted 20 of the 200 known mouse imprint genes, which are crucial for embryonic development. Using the CRISPR genetic editing tool, they were able to ”go around the biological incompatibility of reproduction between two males.”
Complex Genetic Manipulations
The process began with fertilizing an immature, enucleated egg (emptied of its DNA) with the gametes of a male mouse. The resulting embryonic cells were then genetically modified to “disable” or “alter” the 20 targeted imprint genes. These modified cells were subsequently merged with the sperm of a second male within another enucleated egg, creating embryos with DNA from two fathers.
Out of 164 embryos implanted in female mice, seven were born and survived to adulthood. However, these mice exhibited various malformations, including larger-than-average size and hypertrophied organs. They were also sterile and had shorter lifespans compared to “normal” mice.
Building on Previous Research
This study builds on earlier work by Japanese researchers in 2023,who also produced mice with ”two fathers.” Those mice reached adulthood and were fertile, highlighting the evolving nature of this field.
Interestingly, previous research on mice with “two mothers” revealed that they were smaller and lived longer than expected. In contrast, mice with “two fathers” grew excessively and died prematurely. As developmental biologist Kotaro Sasaki from the University of Pennsylvania explained, “Perhaps paternal imprint genes promote growth and maternal imprint genes limit it, and animals need both to reach a healthy size.”
Implications for Humans
while this research is a scientific milestone, its application to humans remains distant. Zhi-Kun Li, the study’s lead researcher, emphasized that “changing 20 imprint genes in humans would not be acceptable, and producing individuals who could not be healthy or viable is simply not an option.”
The team acknowledges that laboratory procedures for human cells are not yet established, and health risks remain a significant concern. Ethical considerations regarding the creation of humans with a double paternal line have also been largely omitted from the discussion.
Key Findings at a Glance
| Aspect | Details |
|————————–|—————————————————————————–|
| Species | Mice |
| Genetic Tool | CRISPR |
| Targeted Genes | 20 of 200 imprint genes |
| Survival Rate | 7 out of 164 embryos reached adulthood |
| Physical Traits | Larger size, hypertrophied organs, sterility, shorter lifespan |
| Previous Research | Mice with “two fathers” born in 2023 were fertile and reached adulthood |
Looking Ahead
The researchers plan to extend their approach to primates, further exploring the possibilities of genetic manipulation. While human applications are “still very distant,” this study represents a significant step forward in understanding genomic imprinting and its role in reproduction.
As the scientific community continues to push the boundaries of genetic research, the ethical and practical implications of such advancements will undoubtedly remain at the forefront of the conversation.
For more details on this groundbreaking study,visit the original publication in Cell Stem Cell here.
Interview on Breakthrough Genetic Research: Mice with Two Fathers
Editor: Thank you for joining us today. Could you start by explaining the significance of the recent study where mice were conceived with two fathers?
guest: Absolutely. This study, conducted by researchers at the Chinese Academy of Sciences in Beijing, is groundbreaking because it successfully created mice with genetic material from two male parents. Published in Cell Stem Cell, this research advances our understanding of genomic imprinting and opens new possibilities for genetic manipulation in mammals, including primates.
Editor: What is genomic imprinting, and why is it crucial in this context?
Guest: Genomic imprinting refers to the phenomenon where certain genes are expressed differently depending on whether they are inherited from the mother or the father.for healthy embryonic development,a balanced expression of these “imprint genes” is essential. Without this balance, gene deregulation can lead to developmental anomalies. In this study, scientists targeted 20 of the 200 known imprint genes in mice to overcome the biological incompatibility of reproduction between two males.
Editor: Can you walk us through the process the researchers used to achieve this?
Guest: Certainly. The process began with fertilizing an immature, enucleated egg (which had its DNA removed) with the sperm of a male mouse. The resulting embryonic cells were then genetically modified using the CRISPR tool to alter the 20 targeted imprint genes. These modified cells were merged with the sperm of a second male within another enucleated egg, creating embryos with DNA from two fathers. Out of 164 embryos, seven survived to adulthood, though they exhibited physical abnormalities like larger size, hypertrophied organs, sterility, and a shorter lifespan.
Editor: How does this study build on previous research?
Guest: This work builds on a 2023 study by Japanese researchers, who also produced mice with two fathers. Importantly, those mice were fertile and reached adulthood, demonstrating progress in this field. Additionally, earlier research on mice with two mothers showed they were smaller and lived longer than normal mice. This suggests that paternal imprint genes may promote growth,while maternal imprint genes limit it,and a balance between the two is necessary for healthy development.
Editor: What are the potential implications of this research for humans?
Guest: While this is a significant scientific milestone, applying this to humans is far from feasible. Zhi-Kun li, the lead researcher, emphasized that modifying 20 imprint genes in humans would be unacceptable due to health risks and ethical concerns. The procedures for human cells are not yet established, and creating individuals who might not be healthy or viable is not an option.The ethical implications of a double paternal lineage in humans also remain unaddressed.
Editor: What are the key findings of this study?
Guest: The key findings include the successful use of CRISPR to modify imprint genes, a 7 out of 164 survival rate for embryos, and the physical and developmental abnormalities observed in the surviving mice. This research also highlights the importance of balancing maternal and paternal imprint genes for healthy growth and development.
Editor: What’s next for this line of research?
Guest: the team plans to extend their approach to primates, further exploring the possibilities of genetic manipulation. While human applications remain distant, this study represents a significant step forward in understanding genomic imprinting and its role in reproduction. Ethical and practical considerations will continue to be central as this research progresses.
Editor: Thank you for shedding light on this fascinating study. For readers who want to learn more, they can access the original publication in Cell Stem Cell here.