Giant pandas (Ailuropoda melanoleuca) belong to the order Carnivora, but they mainly feed on bamboo, and their unique dietary adaptability has always been the focus of research. Recent studies indicate that plant-derived microRNAs (miRNAs) can be delivered to animal organisms via exosomes — nano-sized vesicles (40-100 nm) released by various cell types into the extracellular space — and exert cross-kingdom regulatory effects on gene expression. To explore the role of plant-derived miRNAs in the dietary adaptation of giant pandas, scientists in China collected blood samples from three groups of pandas (juvenile females, adult females, and adult males) and extracted exosomes from the blood for small RNA analysis. Their results show that plant-derived miRNAs can enter the bloodstream of giant pandas and exert cross-kingdom regulatory effects, potentially playing a vital role in their dietary adaptation process.
Giant panda cub Xiao Liwu and his mother Bai Yun at the San Diego Zoo.
“We showed that plant-derived miRNAs are present in the blood of giant pandas,” said Dr. Feng Li, a researcher at China West Normal University.
“Our study proved that bamboo used as food for giant pandas does affect the change of giant pandas’ feeding habits.”
In the study, the researchers took blood samples from seven giant pandas, including three adult females, three adult males, and one juvenile female.
In those samples, they found 57 miRNAs that were likely derived from bamboo.
“miRNA in bamboo can enter giant pandas’ bodies through diet, be absorbed by the intestine, enter the blood circulation, and then regulate when the giant panda’s RNA transfers information, thus playing a role in regulating the gene expression of giant pandas,” Dr. Li said.
These plant-derived miRNAs can regulate different physiological processes, including growth and development, biological rhythms, behavior, and immune responses.
“miRNA in bamboo is also involved in the regulation of smell, taste, and dopamine pathways of giant pandas, all of which are related to their feeding habits,” Dr. Li said.
“As pandas eat more bamboo as they grow, certain miRNAs accumulate, modulate gene expression, and aid in the adaptation to the taste of bamboo.”
“These miRNAs might also influence giant pandas’ sense of smell and enable them to pick out the freshest and most nutritious pieces of bamboo plants.”
“Accordingly, miRNAs from bamboo may facilitate the adaptation of giant pandas from a carnivorous to a plant-based diet.”
The authors also found that pandas with different ages and sexes had different miRNA compositions in their blood.
“Only miRNAs that can specifically play a role in regulating gene expression can remain in the body, and those that do not play a role will be expelled,” Dr. Li said.
“For example, some miRNAs regulate reproductive processes and can thus only be found in the blood of pandas of a certain sex or age.”
“The fact that miRNA could transmit signals from plants to animals, may open doors for studying the treatment and prevention of animal diseases.”
“Plant miRNAs may also participate in regulating the animal immune system, enhancing animals’ disease resistance.”
Similarly, studying plant miRNA-induced changes could also help to assess and improve the safety of plant-based foods for animals and humans.
However, to draw definitive conclusions about the potential of miRNA in general and the effects it might have on giant pandas, more research is needed.
“The giant panda is a very precious national treasure in our country, and blood samples are not easy to get,” Dr. Li concluded.
“If possible, we hope to collect blood samples of young pandas who have not yet eaten bamboo for research, and perhaps get more surprising results.”
The results were published in the journal Frontiers in Veterinary Science.
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Helin Tan et al. 2025. Cross-kingdom regulation of gene expression in giant pandas via plant-derived miRNA. Front. Vet. Sci 12; doi: 10.3389/fvets.2025.1509698
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