How would you like it if you could recharge just by sitting out in the Sun? The ability to use sunlight to convert carbon dioxide (CO2) and water into oxygen and energy is traditionally the exclusive domain of plants and algae. Now, however, researchers in Japan have successfully created photosynthetic animal cells.
The biologists took chloroplasts—the cell components responsible for photosynthesis—from red algae and injected them into hamster cells. As a result, the animal cells gained the ability to photosynthesize light. This achievement, detailed in a study published on October 31 in the journal Proceedings of the Japan Academy, challenges the assumption that combining chloroplasts with animal cells is impossible.
“As far as we know, this is the first reported detection of photosynthetic electron transport in chloroplasts implanted in animal cells,” Sachihiro Matsunaga from the University of Tokyo, who co-authored the paper, said in a University of Tokyo statement. Photosynthetic electron transport is the stage of photosynthesis that produces a plant or algae’s energy.
“We thought that the chloroplasts would be digested by the animal cells within hours after being introduced,” he added. “However, what we found was that they continued to function for up to two days, and that the electron transport of photosynthetic activity occurred.”
The researchers confirmed this by analyzing the chloroplast within the hamster cells through several imaging techniques, and applied a method that uses pulses of light to establish that the photosynthetic electron transport was indeed happening. “We speculated that chloroplasts incorporated into animal cells may remain stable and continuously produce energy regardless of environmental conditions,” they wrote in the study.
While the idea of solar-powered animals is intriguing, that’s actually not the goal; the team’s vision for the future application of this technology is more practical. They suggest that “planimals,” as they’re called, could be incorporated into artificial tissue engineering. Lab-grown tissue sometimes struggles to grow because of a lack of oxygen, which could be solved by introducing photosynthetic animal cells.
“Lab-grown tissues, such as artificial organs, artificial meat and skin sheets, are made of multiple layers of cells. However, there is a problem that they cannot increase in size due to hypoxia (low oxygen levels) inside the tissue, which prevents cell division,” Matsunaga explained. “By mixing in chloroplast-implanted cells, oxygen could be supplied to the cells through photosynthesis, by light irradiation, thereby improving the conditions inside the tissue to enable growth.”
The researchers noted that the chloroplast-infused hamster cells also had a higher growth rate, which hints that the chloroplast passed on a carbon source (fuel) to the animal cells in addition to oxygen.
The team plans to continue its groundbreaking research on these “planimal” cells. Who knows—maybe in the future, your houseplants won’t be the only ones soaking up the sun for a boost.
