Saving Pandas: One Cell at a time
With only 2,000 giant pandas remaining in the wild, the species face significant threats from habitat destruction, human encroachment, and limited genetic diversity. The question is, how can they be saved? Researchers have been actively seeking solutions to preserve this beloved species. In a promising discovery, a team of biologists has successfully converted panda skin cells into “induced pluripotent stem cells” (iPSCS), cells that can be transformed into almost any other cell in the body. This research is a monumental step forward in creating primordial germ cells, the biological predecessors to sperm and egg cells, thereby paving the way for new reproductive methods. This research holds the potential not only to breed giant pandas but also to treat diseases and expand the genetic diversity of these giant pandas (Phys.org, 2024).
Induced pluripotent stem cells, or iPSCs, are adult cells reprogrammed to revert to a pluripotentstate, meaning they can differentiate easily. This means the cells have the potential to turn into almost any cell type in the body. Originally developed in 2006 by Shinya Yamanaka and Kazutoshi Takahashi at Kyoto University (Embryo Project, 2006), iPSCs are now used in various places in regenerative medicine and conservation biology. Unlike embryonic stem cells (ESCs), which are harvested from embryos, iPSCs offer a more “moral” alternative as they do not require the destruction of an embryo and can be sourced from adult tissues, such as skin or blood cells. iPSCs have shown promise in other endangered species. Researchers have successfully created iPSCs from rare species like the northern white rhino, Tasmanian devil, and even a rare zebra, showing the huge role that iPSCs can play in conserving species (Science.org, 2024). By creating cells that can eventually mature into reproductive cells or even entire organs, iPSCs are vital in the preservation of species. The adaptability of iPSCs for such applications has opened new avenues in conservation and biodiversity research. (Phys.org, 2024).
For the giant panda iPSC research, the team selected fibroblast cells, a type of skin cell integral to the structure and function of the skin. Fibroblasts produce collagen and also play a role in tissue repair. These cells are ideal for iPSC creation because they are accessible and can be sourced without invasive procedures. Transforming fibroblasts into iPSCs, however, is not straightforward. Each animal species requires a unique reprogramming protocol because the transcription factors and reprogramming conditions vary across species. For giant pandas, scientists had to identify specific factors that would make the fibroblasts turn back into their pluripotent state. (Phys.org, 2024)
To convert giant panda fibroblasts into iPSCs, researchers introduced a carefully chosen combination of transcription factors and a specialized microRNA cluster known to aid in reprogramming. This microRNA cluster, when combined with the appropriate transcription factors, helped activate genes within the fibroblasts to reprogram them back to an embryonic-like, pluripotent state (Science.org, 2024).
There are two different kinds of iPSCs: naïve and primed. The former are early-stage, highly flexible cells that can easily form multiple cell types or even entire organisms under specific conditions, while the latter are further along the differentiation pathway. In this study, the researchers achieved a primed pluripotent state in panda iPSCs. This state is vital because it allows the iPSCs to differentiate into specialized cells needed for reproductive applications. However, the research team was not able to revert the iPSCs to their naïve state (Phys.org, 2024).
The giant panda iPSCs, or GPiPSCs, developed in this research demonstrated the ability to differentiate into the three primary germ layers—endoderm, mesoderm, and ectoderm—If successful, the ability to produce primordial germ cells from iPSCs could enhance breeding programs for pandas by creating reproductive cells without using invasive procedures. Additionally, GPiPSCs offer potential applications in medical research for these giant pandas, such as developing treatments for diseases that affect the panda population (Science News, 2024).
This research on panda iPSCs opens promising pathways to conserving endangered species. The giant panda’s limited genetic diversity and reproduction challenges—joined with their isolated populations and inbreeding risks—make it imperative to try innovative approaches like stem cell research. Further research will focus on refining GPiPSC production methods, particularly in developing fully naïve iPSCs that can develop fully into chimeric embryos. Additionally, creating primordial germ cells from these iPSCs would offer flexibility in conservation, helping scientists support giant panda reproduction even in situations where normal breeding approaches are not possible (Science.org, 2024).
Not only is this discovery hugely impactful for the giant panda population, but for all animals around the world. Creating these cells could save numerous species on the verge of extinction. While each animal’s transcription process and microRNA are different, the fact that researchers made the discovery work for pandas is promising for other species (Science News, 2024).
References
Liu, Y., Zhang, S., Zou, G., An, J., Li, Y., Lin, D., Wang, D., Li, Y., Chen, J., Feng, T., Li, H., Chen, Y., Zhang, M., Kumar, M., Wang, L., Hou, R., & Liu, J. (2024). Generation and characterization of giant panda induced pluripotent stem cells. Science Advances, 10(38). https://doi.org/10.1126/sciadv.adn7724
Yirka, B. (2024, September 23). Giant panda skin cells transformed into stem cells to help ensure their survival. Phys.org. https://phys.org/news/2024-09-giant-panda-skin-cells-stem.html