Rockefeller University researchers have found a new organ in the gut of a fruit fly – a surprising discovery, staring us in the face, of one of the most well-studied animals in all of science.
The new organelle stores phosphate, which is essential for life. When there is a shortage, it releases the water reservoir in the form of phospholipids, which are the main part of the cell membrane structure.
“This is one of the first studies to find phosphate storage in an animal cell,” said Rebecca Weil. Natural Gemma Conroy. A structural biologist at a French state research organization National Center for Scientific ResearchWild did not participate in the study.
“It’s really fun.”
Rockefeller University researchers have discovered a new organ in the gut of a fruit fly – one of science’s most studied models.
What are the body parts? An Organelle It’s a structure similar to an organ in a cell – specialized organs to do specific jobs, which allow the whole cell to function, just like your heart, lungs, and liver do for your entire body.
You may remember some from biology class: The nucleus stores the genetic code. mitochondria the powerhouse of the cell; The flagellum causes the cell to swim around. But no matter how long we’ve been studying cells — basically since the invention of the microscope — we continue to discover new organelles, including the olfactory neurons found inside. Just this summer.
This is to reveal the secrets hidden in the cells, says Rockefeller University geneticist Charles Xu, whose team discovered the new organ in 2011. NatureHe told Conroy.
“The beauty is there, just waiting for us to find it.”
Fos for us: Phosphate plays a lot Important roles In our physiology. It is a key component of enamel and other materials that strengthen teeth, is responsible for mineralizing bone, and is an essential component of cell membranes, DNA, RNA, and proteins.
Xu is not set on an organelle hunt; He wanted to study the role of phosphate in regulating tissue regeneration in fruit flies, Conroy reports.
To do this, the team fed fruit flies phosphonoformic acid, which inhibits the uptake of phosphorus (from which phosphate is derived) in cells. When the researchers examined the cells, they found that turning off this supply was one factor. Increase In cell production.
Organelles called PXo bodies act as reservoirs for electrolytes essential to life.
To find out why, Xu and colleagues looked at how phosphate affects gene expression. They dialed in the called gene. PXoIt is similar to a gene found in mammals to make phosphate-sensing proteins. When phosphate levels are low, the expression PXo Decreased – send cell division spins. On the other hand, when led by engineering, the division decreased PXo to overexpress the protein.
The group has given an account PXo A fluorescently labeled protein to track it – and found it involved with secretory structures in the cell.
“These were very visible,” Xu told Conroy, “and we wondered what they were.
brand new Organelle: Upon closer inspection, the team found oval-shaped structures with multiple membrane layers PXo Protein shepherd phosphate on them. Properly named a PXo Organelles convert phosphates into phospholipids, which cells use in membrane construction.
When fruit flies’ phosphate intake is reduced, PXo The bodies open up, shedding their phospholipids and triggering a stress signal that causes cell division. (Increasing cell production may be a way to try and stabilize phosphate levels, says Xu Conroy; the idea is that more cells can take up more of the phosphate that’s suddenly floating around.)
The discovery could spark the search for phosphate-storing organelles in other animals – including humans. Further research will help us understand how the organelle fits into the cell’s life, how it interacts with others, and how it changes over time.
“It opened the door to many other questions,” Xu said.
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