Researchers at the University of Tokyo have successfully developed a technique to insert chloroplasts from algae into animal cells, potentially revolutionizing sustainable energy and artificial meat/organ creation. This breakthrough could lead to the development of ‘planimal’ cells with plant capabilities, impacting medical research, food production, and energy generation.
Researchers at the University of Tokyo have successfully developed a technique to insert chloroplasts isolated from algae into animal cells, a feat that could revolutionize sustainable energy and how artificial meat and organs are created.
The Origin of Chloroplasts
Chloroplasts, the parts of cells that allow plants and algae to photosynthesize, are thought to have originated more than 1 billion years ago, when photosynthetic cyanobacteria lived symbiotically within other primitive cellular organisms. Replicating the development of this photosynthetic capability in other cells today—by placing chloroplasts inside animal cells—was previously thought impossible: Animal cells recognize chloroplasts as foreign bodies and digest them.
A Breakthrough in Transplanting Chloroplasts
However, a Japanese research team has changed this thinking. They have developed a technique to isolate photosynthetically active chloroplasts from the primitive algae Cyanidioschyzon and transplant them into Chinese hamster ovary (CHO) cells, a type of cultured animal cell line, and still retain their functionality.
Structure and Functionality of Transplanted Chloroplasts
The research team used fluorescence laser microscopy and super-resolution microscopy to capture cross-sectional images of the cells and observe how both the cells and chloroplasts behaved. They found that the chloroplasts taken up into the CHO cells were present within the cytoplasm, with some surrounding the cell nucleus. After the chloroplasts were taken up, the CHO cells showed signs of behaving normally, including continuing to divide.
Photosynthetic Activity and Electron Transport
Further observations using an electron microscope revealed that the structure of the thylakoid membrane of the chloroplasts was maintained for at least two days. Measurements of photosynthetic activity using microscopic imaging and pulse modulation confirmed that electron transport for photosynthesis was normal during this period. However, on the fourth day after the transfer, the structure of the thylakoid membrane collapsed, and the chloroplasts’ photosynthetic activity significantly decreased.
Potential Applications
This research points to new possibilities in tissue engineering. Artificial organs, artificial meat, and skin sheets made from multiple cell layers have limited growth when exposed to low oxygen levels. If cells incorporating chloroplasts could be added, it might be possible to supply oxygen to the tissue and promote growth simply by shining light on it.
Future Research Directions
The research team will now continue its research with the ultimate aim of creating “planimal” cells that have plant capabilities. Planimal cells, if possible, could be a game changer in multiple industries, including medical research, food production, and energy generation. To achieve this, a technology is required that allows transplanted chloroplasts to maintain photosynthetic activity for longer inside animal cells.
Quantifying Oxygen Generation and Carbon Dioxide Fixation
In the future, it will also be necessary to quantify the amount of oxygen generated by the transplanted chloroplasts and the amount of carbon dioxide fixed inside the animal cells. This can be done using a technique called isotope labeling.
Conclusion
This achievement marks a significant breakthrough in the field of biology and has potential applications in sustainable energy, artificial meat and organ creation, and medical research. Further research is needed to overcome the current limitations and achieve the goal of creating planimal cells with plant capabilities.
