Understanding where we come from can shed light on how life itself evolved into its stunning complexity. The study dives into the origins of the very cells that make healing, growth, and regeneration possible in animals: stem cells. By tracing the surprising roots of critical proteins to ancient single-celled organisms, this research uncovers a story that links humanity to its earliest ancestors, revealing how the building blocks of life evolved long before animals walked the Earth.
Scientists have long wondered about the origins of multicellular animals and how their cells develop into such a wide variety of forms and functions. A new study led by Professor Ralf Jauch, Dr. Alex de Mendoza, and their colleagues from the University of Hong Kong and the Max Planck Institute for Terrestrial Microbiology sheds light on the history of Sox and POU proteins, which are essential to the functioning of animal stem cells. Published in Nature Communications, this research challenges the previous assumption that these proteins only appeared in animals.
Findings from this study reveal that Sox and POU proteins were present in the single-celled ancestors of animals. These proteins were discovered in choanoflagellates, single-celled organisms closely related to animals. Remarkably, Sox proteins in these organisms were found to be similar to mammalian versions, particularly Sox2, and could even transform mouse body cells into cells with the ability to develop into any type of specialized cell. However, POU proteins from these organisms, while similar in structure, lacked the necessary traits to perform this transformation.
Experts in the field may find the lead researcher’s comments compelling. Professor Jauch explained, “Our findings imply that the evolution of animal stem cells might have involved the adaptation of a pre-existing set of transcription factors.” This means that the characteristics of Sox proteins from ancient organisms may have made them suitable for early animal stem cell processes.
Advanced techniques allowed the researchers to recreate versions of ancient Sox proteins and test their abilities. These experiments showed that such proteins could induce the transformation of body cells into versatile stem cells in modern animals. This suggests that the tools needed for creating stem cells existed long before animals emerged, potentially making the shift to multicellular life more feasible.
Moving forward, the implications of this work expand our understanding of how cell diversity and complexity evolved. The researchers highlight that these proteins, refined over time, play a crucial role in helping cells maintain their ability to renew themselves and transform into specialized forms. Their study also identifies gaps in older research that may have underestimated how widespread these proteins were in ancient single-celled relatives of animals.
Ultimately, this research offers strong evidence that Sox and POU proteins were key players in the development of animal stem cells, even before multicellular organisms existed. It connects a significant missing piece in the story of evolution and sets the stage for further studies into the mechanisms that helped life transition from simple to complex forms.
Journal Reference
Gao, Y., Tan, D. S., Girbig, M., et al. “The emergence of Sox and POU transcription factors predates the origins of animal stem cells.” Nature Communications (2024). DOI: https://doi.org/10.1038/s41467-024-54152-x
About the Authors
Professor Ralf Jauch is a distinguished scientist specializing in stem cell biology and transcriptional regulation. Based at the University of Hong Kong, he is a leader in uncovering the molecular mechanisms that drive cellular identity and pluripotency. His work focuses on transcription factors like Sox and POU proteins, which play pivotal roles in stem cell maintenance and differentiation. With a deep commitment to understanding the evolutionary origins of these factors, Professor Jauch bridges the fields of molecular biology and evolutionary science. His innovative research employs state-of-the-art techniques to reconstruct ancient proteins, shedding light on how cellular complexity emerged over evolutionary time. Widely respected for his scientific rigor, he actively collaborates with global researchers and mentors the next generation of scientists. Through his groundbreaking studies, Professor Jauch continues to make significant contributions to both stem cell biology and our understanding of life’s earliest molecular foundations.
Dr. Alex de Mendoza is a prominent evolutionary biologist whose research explores the molecular origins of complex life forms. Affiliated with Queen Mary University of London, he is dedicated to decoding how early transcription factors, such as Sox and POU, contributed to the evolution of multicellular organisms. Dr. de Mendoza’s work combines evolutionary theory with cutting-edge molecular biology, enabling him to uncover the ancient genetic mechanisms that shaped the diversity of life. His investigations delve into how unicellular ancestors laid the groundwork for animal stem cells, revealing a fascinating link between ancient proteins and modern biology. Known for his interdisciplinary approach, Dr. de Mendoza collaborates with scientists worldwide to address fundamental questions about life’s evolution. Through his research, teaching, and scientific outreach, he continues to inspire curiosity about the origins of multicellularity and the molecular pathways that connect ancient life to today’s biological systems.
