Does bamboo WANT to be eaten? Tan & colleagues have found bamboo may actively influence pandas through microRNA (miRNA) molecules that enter the pandas’ bloodstream, manipulating their biology to prefer plants despite having carnivore digestive systems.
Scientists at China West Normal University analysed blood samples from seven giant pandas and identified 57 microRNAs (miRNAs) – tiny genetic molecules – that originated from bamboo plants. miRNAs act as regulators for gene expression, deciding which genes produce proteins and which don’t.
“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,” says senior author Dr Feng Li.
The miRNAs interfere with genes that control taste perception, smell, and the brain’s dopamine reward system. For example, one miRNA targets the TAS2R3 gene responsible for sensing bitterness which may help identify harmful substances in bamboo while selecting edible parts.
Eight bamboo miRNAs may target the dopamine metabolism pathways in pandas. Dopamine is like a chemical messenger in your brain that signals pleasure. By slowing dopamine processing, these molecules may enhance pleasurable sensations when eating bamboo, reinforcing pandas’ preference for the plant.
It seems only miRNAs interacting with gene expression stay in the bloodstream. Some miRNAs detected only in juvenile pandas target genes involved in growth and development. Others found only in males regulate sperm production, while those in females affect oestrogen, showing age and sex specificity.
Tan & colleagues researchers also found plant miRNAs that help pandas adapt to their bamboo diet by regulating digestion, metabolism, and energy conservation. This is particularly important for pandas because bamboo is so nutritionally poor. The miRNAs work with MAPK pathways to regulate cell growth.
At the same time they also affect AMPK genes to inhibit energy-consuming processes and activate energy-producing pathways. As the paper states: “This mechanism may explain why the giant panda, despite consuming nutritionally poor bamboo, can attain a relatively robust physique.”
This study is the first to demonstrate “cross-kingdom” gene regulation in giant pandas, where molecules from one species (bamboo plants) can influence gene expression in another species (pandas). It suggests that bamboo isn’t a passive victim for pandas, but is steering them.
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,” Li points out.
Tan H, Wang C, Li F, Peng Y, Sima J, Li Y, Deng L, Wu K, Xu Z and Zhang Z (2025) Cross-kingdom regulation of gene expression in giant pandas via plant-derived miRNA. Front. Vet. Sci. 12:1509698. https://doi.org/10.3389/fvets.2025.1509698
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Image: Canva.
