Panda-potent!

Image Credit: [1]

Written by Wonjong Ko ‘28

Edited by Alicia Kim ‘28

Pandas are one of the most influential animals, serving as both a global icon and the national treasure of China. With their black and white fur coats and their large, clumsy demeanors, they have gained worldwide fame and adoration. They are gentle, solitary, and slow-moving. These exact traits unfortunately make them vulnerable, as they lack the proper survival skills to protect themselves from human deforestation. Recent conservation efforts have propelled their populations upwards, but a major concern still looms over the future of their species (1).

While decades of captive breeding programs have allowed the giant panda to rebound from previous numbers, this strategy alone is not sustainable and cannot guarantee the survival and health of the species. Pandas reproduce only a few days each year since females are not fertile often. Additionally, cub survival rates in captivity are somewhat low. Furthermore, there is limited genetic diversity within captivity which not only reduces the resilience to disease, but also threatens the overall health of future generations (1). So, what can be done if pandas are threatened in the wild and lack proper genetic variety in conservation sites?

This is where induced pluripotent stem cells come in. Induced pluripotent stem cells (iPSCs) are a type of stem cell that have the potential to differentiate into any cell type. They are created by reprogramming adult body cells, such as skin, back into an embryonic-like state. This technology has already shown promise in conservation science with endangered species such as the northern white rhinoceros and the Tasmanian devil (2,3). For giant pandas, researchers had long struggled to replicate these results. However, new advancements have been accomplished resulting in a breakthrough for the panda community (3).

Jing Liu, a stem cell biologist at the Chinese Academy of Sciences, has successfully obtained iPSC clones from giant panda fibroblasts, which are cells that are a key component of connective tissues such as cartilage. At first, Liu attempted to use conditions that have worked for humans and mice in the past, although this was surprisingly unsuccessful. This prompted Liu’s team to look deeper into the biology of giant panda fibroblasts, where they identified a specific microRNA cluster that enhanced cellular reprogramming by fine-tuning how certain genes were expressed. When they added this with panda-specific transcription factors—proteins that switch genes on or off—the two mechanisms worked together to overcome previous roadblocks, allowing the team to successfully produce giant panda iPSCs (3,4). However, this entire process of creating iPSCs from giant panda fibroblasts took nearly five months, much too long to be sustainable for improving panda population. Liu’s team analyzed their current protocol and were able to tweak parts of the reprogramming process. For example, they changed the cell culture medium to include certain cell signal pathway modulators, kinase blockers, and epigenetic inhibitors to cut the experiment down to a little less than a month. Speed is a critical part of the experiment, but the true test would be whether these cells could function as genuine, healthy stem cells (4).

Figure 1: Process of how fibroblasts can  turn into specialized cells

Image Credit: [3]

While cutting down its time is an important factor in this experiment, ensuring that the iPSCs are usable and healthy is paramount. In order for iPSCs to be effective, they need to be able to differentiate into three germ layers called the endoderm, mesoderm, and ectoderm. Germ layers are the foundations of all tissues in the body. Demonstrating that panda iPSCs can reliably produce cells from all three germ layers is crucial, because it shows that these lab-grown cells could one day give rise to eggs, sperm, or even entire tissues needed for breeding and health research (4). To test this, researchers analyzed the formation of embryoid bodies, a group of pluripotent stem cells that behave similar to an embryo developing. They noticed that ectodermal markers increased early in the developmental stage, while mesodermal and endodermal markers increased later on. To further test this hypothesis, they injected giant panda iPSCs into mice, where a mass composed of all three layers started to form. It was a success, proving that giant panda iPSCs can truly function like stem cells from other species (4). However, this is only the beginning. While demonstrating pluripotency confirms their potential, turning this potential into a practical tool that can be used for reproduction and genetic rescue will require more research. Scientists now face the task of coaxing panda iPSCs down the right developmental pathways, ensuring that these cells not only grow properly but also take on the exact roles needed to boost population numbers and strengthen genetic diversity (3,4).

While generating iPSCs is not necessarily like creating dinosaurs from Jurassic Park or cloning Dolly the sheep, they represent an important step in conservation. This breakthrough illustrates that by combining modern biotechnological advancements with traditional efforts, scientists can address the growing issue of population endangerment not just in pandas, but with all animals. Getting the Earth’s wildlife back to normal will not take a year. It may not even take a decade. But with consistent progress and more technological innovation, there remains a real hope for biodiversity and securing the survival of endangered species for generations to come.

References

1. Giant Panda [Internet]. National Geographic Kids. National Geographic; 2015. Available from: https://kids.nationalgeographic.com/animals/mammals/facts/giant-panda

2. National Geographic Kids. Giant panda facts [Internet]. Washington (DC): National Geographic; 2024. Available from: https://kids.nationalgeographic.com/animals/mammals/facts/giant-panda

3. Duke Vertices. Saving the giants: advances in stem cell research for panda conservation [Internet]. Durham (NC): Duke Vertices; 2024. Available from: https://www.dukevertices.org/blog/saving-the-giants-advances-in-stem-cell-research-for-panda-conservation

4. The Scientist. Stem cells could save the giant panda [Internet]. 2024. Available from: https://www.the-scientist.com/stem-cells-could-save-the-giant-panda-72191

5. Liu J, Chinese Academy of Sciences. Generation and characterization of giant panda induced pluripotent stem cells [Internet]. Beijing (CN): Chinese Academy of Sciences;