Scientists have observed for the first time that coral cells swallow photosynthetic algae.This is a key step in understanding their most important symbiotic relationship
Coral reefs are an important biodiversity hotspot in the world’s oceans. The researchers of a new study, Publish At the frontier of marine science, said. However, in recent decades, they have been under tremendous pressure due to man-made warming.
In particular, the important symbiotic relationship between corals and tiny algae called dinoflagellates has become tense.
“Coral cells absorb algae and provide them with shelter and the cornerstone of photosynthesis. In return, the algae provide corals with the nutrients they synthesize,” the senior author of the study and professor at the Okinawa Institute of Science and Technology (OIST) Noriyuki Satoh (Noriyuki Satoh) Graduate university, Explanation At the university press conference.
However, due to pressure factors such as rising temperatures, acidification and pollution, corals will expel algae and eventually die in large-scale bleaching events.
The university pointed out that stony corals from the Acroporidae family are said to be the most common type of coral in tropical and subtropical reefs.They are also important to architecture Coral reef Because they grow fast and provide a calcium carbonate skeleton. However, they are also particularly susceptible to this bleaching event, so understanding the “cellular and molecular mechanisms” of their symbiosis with algae is the key to coral reef protection.
OIST pointed out that one problem with this work is that coral cells are said to be “very difficult” to cultivate, so previous studies used cells from related organisms.
“However, to date, few in vitro experimental systems have been designed to clarify this mechanism,” the researchers wrote.
In their research, scientists from Japan successfully achieved this feat by culturing a larval cell line from the stony coral Acropora tenuis in a petri dish. The researchers then added dinoflagellate, and sure enough, they observed for the first time the process of engulfing algae by coral cells.
inside video In the observation of “World No. 1”, one can see coral cells reaching out to the dinoflagellate and engulfing them. The in vitro symbiosis process only took about 30 minutes. Within 24 hours, about half of the corals had absorbed algae “in a reproducible way.”
The researchers pointed out that once the algae is contained, the coral cells become “round and less mobile.” The symbiosis state lasted for about a month, and then the coral cells died.
The researchers said that the researchers’ work not only showed for the first time that coral cells swallowed algae, but it also provided clues about how the symbiotic relationship between them first began. Importantly, it also sheds light on how we can save coral reefs in the future.
The researchers wrote: “The knowledge gained in future studies using this system may improve our understanding of coral biology related to bleaching, thereby providing clues for the improvement of coral reef protection methodologies.”
Photo: GREGORY BOISSY/AFP/Getty Images
