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Unveiling the Role of Ancient Viral DNA in Mammalian Embryo Development
Recent studies indicate that our genomes are significantly shaped by remnants of ancient viral DNA, particularly transposable elements, which cover over half of our genetic makeup. Once considered merely the “dark side” of genetics, these elements are now recognized for their key functions in the early stages of embryo development, according to researchers at Helmholtz Munich and Ludwig-Maximilians-Universität (LMU).
Exploring the Unresolved Role of Ancient Viral DNA
During the critical initial hours and days post-fertilization, transposable elements are reactivated, coinciding with a phase in which embryonic cells exhibit remarkable versatility. Despite the clear importance of this plasticity, the precise molecular mechanisms governing it remain largely unexplained. While research in animal models like mice indicates that these viral remnants contribute substantially to cellular adaptability, the universality of this phenomenon among all mammals is still up for debate. The evolution of these viral segments fosters questions about their conservation in mammalian genetics, urging further investigation into how they could impact reproductive medicine and the foundational rules of genome regulation.
Rediscovery of Previously Thought Extinct Viral Elements
A research team directed by Prof. Maria-Elena Torres-Padilla employed innovative techniques to delve into these ancient sequences, constructing a comprehensive single-embryo atlas through comparative studies across mammals, including mice, cattle, pigs, rabbits, and rhesus macaques. The results were revealing: long-thought-extinct viral elements were found to be reactivated in mammalian embryos, with each species expressing a unique set of these elements.
Implications for Gene Manipulation and Research on Cell Plasticity
These findings affirm that transposable element activation is consistent across different species, unveiling opportunities to influence the expression of numerous genes simultaneously. Dr. Marlies Oomen, a co-first author of the study, notes the potential of this approach to manipulate cell identity, particularly in directing stem cell differentiation—a task typically requiring extensive gene manipulation. “Our findings underline the need to grasp the regulatory mechanisms that govern transposable elements,” Oomen stated.
Prof. Torres-Padilla elaborates on the significance of their discovery: “The activation of transposable elements is a hallmark of early embryonic development in several mammals. This is integral because these cells can evolve into any cell type in the body. A deeper understanding of how these cells regulate viral remnants provides valuable insights into the dynamics of cellular versatility, setting the groundwork for future explorations into regulatory elements with implications across health, disease, and cellular functionality.”
Creating an Unprecedented Dataset for Cross-Species Development
Beyond pioneering novel techniques that enhance single-cell and embryo research, this study has produced a highly detailed dataset unparalleled in its scope. While early embryonic development has been a focus for many researchers, studies often concentrate on a singular species, such as mice or humans. This research stands apart by analyzing various mammals, illuminating essential regulatory pathways shared among them. The biological insights gained, along with the extensive data compiled, will prove invaluable for further research in developmental and reproductive biology.
About the Researchers
Prof. Maria-Elena Torres-Padilla serves as the Director at the Institute of Epigenetics and Stem Cells at Helmholtz Munich and holds a professorial position at the Faculty of Biology at Ludwig-Maximilians-Universität (LMU).
Dr. Marlies Oomen is a Postdoctoral Researcher at the Institute of Epigenetics and Stem Cells at Helmholtz Munich.
Source
www.sciencedaily.com