chloroplast, part The cells that allow plants and algae to photosynthesize are thought to have originated over 1 billion years ago, when photosynthetic cyanobacteria lived symbiotically within other primitive cellular organisms.
The evolution of this photosynthetic ability is being replicated in other cells today – by placing chloroplasts inside animals. cells—previously considered impossible: Animal The cells recognize the chloroplasts as foreign bodies and digest them. But a Japanese research team has changed this thinking. It has developed a technique to isolate photosynthetically active chloroplasts from primitive algae cyanidioschizon And they are transplanted into Chinese hamster ovary (CHO) cells, a type of cultured animal cell line, and still retain their functionality.
“To our knowledge, this is the first time that photosynthetic electron transport has been confirmed in chloroplasts transplanted into animal cells,” Let's tell Professor Yukihiro Matsunaga of the University of Tokyo. Electron transport is a major process by which plants And algae produce chemical energy supporting various cellular functions.
Matsunaga's research team succeeded in relocating chloroplasts by promoting phagocytosis by CHO cells, which is the process by which cells digest and break down foreign substances.
The research team then 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 that had been transported in CHO cells were present within the cytoplasm, the liquid that fills the interior of the cell, some of it surrounding the cell nucleus. After taking up the chloroplasts, the CHO cells showed signs of behaving normally, for example by continuing to divide.
Further observations using an electron microscope showed that the structure of the chloroplast's thylakoid membrane – where the enzymes required for photosynthesis are located – was maintained for at least two days. Measurements of photosynthetic activity using microscopic imaging and pulse modulation also confirmed that electron transport for photosynthesis was normal during this period. However, on the fourth day of transfer, the thylakoid membrane structure collapsed and the photosynthetic activity of chloroplasts decreased significantly.
This research points to new possibilities in tissue engineering. artificial limbs, artificial meatAnd sheets of skin composed of multiple cell layers have limited growth when the tissue is exposed to low oxygen levels. If cells containing chloroplasts could be attached, it might be possible to supply oxygen to the tissue and promote growth by exposing it to light.
But to achieve this, a technology is needed that allows the transplanted chloroplasts to maintain photosynthetic activity for a long time inside animal cells. According to the research team, in the future it will also be necessary to determine the amount of oxygen produced by the transplanted chloroplasts and the amount of carbon dioxide stable inside the animal cells, which can be done using a technique called isotope labeling.
The research team will now continue their research, with the ultimate aim of creating “planimal” cells that have the abilities of plants. If possible, planimal cells could be a game changer in many industries, including medical research, food production and energy production.
This story was originally published on wired japan And it has been translated from Japanese.