Could stem cells be the key to helping panda conservation efforts? Photo credit: Sid Balachandran via Unsplash
The giant panda (Ailuropoda melanoleuca) is one of the world’s most loved animals. Yet today, there are only 1,864 left in the wild. Although the threat posed to the giant panda by poaching is less significant now than it has been in the past, habitat loss is increasingly prevalent. The rapid development of infrastructure has fragmented the wild giant panda population, with railways and roads physically separating them.
While there has been success involving captive breeding projects, there are limitations. The majority of captive male pandas will not mate naturally for reasons that are not entirely clear. Additionally, there will always be risks with breeding within a small population, as the lack of genetic diversity seen in the offspring can lead to the accumulation of certain genetic diseases that would be considered “rare” in a wild population. Not all hope is not lost though. In an effort to solve this, scientists have turned to stem cell technology to aid in the fight to save the giant panda.
The majority of captive male pandas will not mate naturally…
Stem cells are unlike many other kinds of cells, with two key properties setting them apart. They have the power to self-renew and also to give rise to many different types of cells (a process known as differentiation). In most species (including the giant panda), stem cells are named based on what they can differentiate into. Pluripotent cells are found in early-stage embryos and can differentiate to form any type of cell. On the other hand, multipotent stem cells are found in particular tissues in adults, such as the brain and bone marrow. This type of stem cell is limited to differentiating into the cells of their tissue of origin. For example, a blood multipotent stem cell would be able to differentiate into either a red blood cell or a white blood cell but would not be able to form a skin cell. Scientists are now interested in “reprogramming” normal, differentiated cells to generate new stem cells that can be used for research or in regenerative therapies to restore damaged tissues. There has been success in the regeneration of multipotent stem cells from the differentiated cells lining the inside of the giant panda’s cheeks. Although this is useful technology, the limited differentiation potential of multipotent stem cells means that the formation of pluripotent cells remains a clear goal.
…a form of giant panda pluripotent stem cells have been created.
A paper published in September 2024 by Jing Liu and his lab describes how, for the first time, a form of giant panda pluripotent stem cells have been created. Induced pluripotent stem cells (iPSCs) are formed from adult differentiated cells that are “reprogrammed” using a variety of genetic tools to revert them into a pluripotent state. There are many advantages to using these iPSCs over traditional stem cells. Although the key benefit is the wide differentiation potential of iPSCs into a whole range of cell types, there are also ethical advantages, as the iPSCs do not need to be harvested from early-stage embryos like traditional pluripotent stem cells would be. This was not an easy process for Jing Liu and his lab, as the techniques used for one species will not necessarily work for another species. The path to success involved a certain degree of trial and error to fine-tune and optimise the growth conditions necessary to sustain this induced pluripotency.
…the techniques used for one species will not necessarily work for another species.
The success of Jing Liu and his lab in producing these giant panda iPSCs provides a beacon of hope for the future of the panda, along with other endangered and vulnerable animals. Currently, the focus is on maintaining the health of the giant pandas currently in the wild and captivity. iPSCs can be used to model the development of many diseases in a lab environment, avoiding the need to study the effects on the animal itself. The effect of new drugs can also be tested on populations of iPSCs to understand better the impact these may have on different cell types. iPSCs can also be used to increase the genetic diversity seen in captive populations when used alongside gene editing technologies. This ultimately helps to prevent genetic disorders and the increased susceptibility to disease often seen in captive populations.
iPSCs can also be used to increase the genetic diversity seen in captive populations when used alongside gene editing technologies.
In the future, there is hope that someday, this iPSC technology will provide the ability to produce gamete (sperm and egg) cells to generate giant panda embryos in vitro to assist their reproduction. Although not possible with current tools, genetic technology is progressing at such a rapid rate that it may only be a matter of years before this is a viable and widespread conservation method.
