To see how corals have already evolved against warm water, Mybom and his colleagues wanted to learn exactly how corals and their complex networks, called a holobiant, can withstand heat. He likened it to a rubber band strength test: how far can you stretch it before breaking it? And how long does it take to get back to regular form?
Karin Kleinhaus, a coral researcher at Stony Brook University, says it is important to understand how these corals work at the cellular level. We need to find out what they do. “
The researchers increased their experiments The pistol They dub the Red Sea simulator in a series of Aquarius. Each aquarium can be adapted to replicate specific water conditions and to expose corals, algae and bacteria at different temperatures for different periods of time. The researchers then examined which genes the corals released during their normal state, how they changed with increasing temperature, and how quickly the gene’s activity returned to normal as the temperature decreased.
They found that all three creatures were able to change all the water. Which gene did they use to heat the water? Corals, for example, begin to use the genes involved in the unfolded protein response, a process used to detect environmental stress and Save homeostasis Cells; In other studies, it has been described as coral. The first line of defense Already against heat, algae rejected the activation of genes related to photosynthesis. Overall, Red Sea species were able to survive temperatures as high as five degrees Celsius, and once scientists lowered the temperature in tanks, the entire holobiant heat returned to normal a week later. Maybom compared their perspective to that of a super-fit athlete who is able to recover quickly after a major workout and prepare for another challenge.
“The paper works really well and sheds light on the early stages of the heat-stress response in heat-tolerant corals,” said Andrea Grotoli, a professor at the Ohio State University School of Earth Sciences who studies coral and climate change. Note that this method has some limitations. Just because genes are active doesn’t mean that corals will eventually make new proteins. It’s an indicator that corals are reacting to their environment, but it’s not the whole story The changes were adapting and I wanted to know how corals change physically.
Grotoli further noted that the longest exposure in the study, up to seven days, is much lower than in many real-life heat waves “Most natural bleaching events last two months longer,” he says.
Maibom agrees that his study does not explain how these new active genes can help corals survive, but he says their identification is a step towards determining it. “It gives an indication of what’s going on.”
It is not clear why these corals have this heat resistance. Others It is not because they evolved in the warmer climates of the Red Sea, but because they came warmer from somewhere. It could be. Water evaporates from near the equator and eventually freezes in large glaciers. The sea level of all the seas trapped in the ice water has dropped, cutting off the Red Sea from the Arabian Sea and turning it into essentially a lake. As water levels have dropped and salt has accumulated, it has become a non-residential environment. But when the glaciers melted and the connection to other parts of the ocean was repaired, new water and life flowed That included the corals in the Arabian Sea, which gradually rose from the heated southern waters. Only these species that were adapted to the heat were healthy enough to send their larvae north to rehabilitate the Gulf of Ababa. “They were elected. It’s like a filter, “said Maibom.