This Photo voltaic-Powered Slug Steals Photosynthetic Equipment for Emergency Meals
A sure species of sea slug steals chloroplasts from algae and homes its contraband in particular organelles that it will probably raid for meals in instances of want
Sea slugs within the genus Elysia are shiny inexperienced as a result of they retailer chloroplasts, the organelles that make vitality in crops.
‘Photo voltaic-powered’ sea slugs have specialised depots of their cells that retailer photosynthetic gear looted from algae, a examine stories. These depots present simply the correct chemical atmosphere to maintain the stolen equipment, known as chloroplasts, alive and dealing to show daylight into vitamins.
“It was the wildest factor that we had seen,” says examine co-author Nicholas Bellono, a biologist at Harvard College in Cambridge, Massachusetts. The authors additionally discovered that, in lean instances, the slugs can raid these compartments to devour chloroplasts.
The compartment “is mainly like a transferring fridge of chloroplasts the place, after a interval of hunger, the slugs can swap from storage to consumption to outlive”, Bellono says.
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The findings had been revealed in Cell.
Inexperienced grazer
Scientists found many years in the past that sure species of sea slug retailer chloroplasts from the algae they eat, a weight loss plan that may flip the slugs shiny inexperienced. However nobody understood how the slugs maintain these international organelles alive with out the assist of the remainder of the algal cell.
Bellono and his staff added chemical tags to proteins newly made by the slugs’ personal cells. They discovered that many of the proteins in a slug’s chloroplasts had been made by the slug — not by the unique algae. That meant the slug was serving to to take care of the chloroplasts.
When the scientists regarded on the chloroplasts below a microscope, they discovered that the organelles had been housed in particular compartments within the slugs’ guts. Every compartment was surrounded by a membrane that examined optimistic for markers sometimes present in mobile buildings known as phagosomes, which fuse with different buildings known as lysomes to digest unneeded organelles. The researchers named this construction the kleptosome, after a Greek phrase meaning to steal.
Lifetime of crime
The staff additionally discovered that these organelles contained ion channels — receptors that convert chemical messages into electrical alerts. Amongst them is one known as P2X4, which opens in response to the presence of ATP, an energy-carrying molecule produced throughout photosynthesis.
When Bellono and his staff blocked this channel in slugs’ kleptosomes, oxygen manufacturing from photosynthesis dropped, displaying that the kleptosome is actively concerned in maintaining the chloroplasts functioning.
Having found the existence of the kleptosome, the researchers questioned whether or not it helps the slugs to withstand hunger. They in contrast the solar-powered slug Elysia crispata with Aplysia californica, a non-photosynthetic slug that lacks kleptosomes. Aplysia died after three to 4 weeks with out meals, whereas Elysia might survive for as much as 4 months. But, after 4 weeks, the Elysia slugs misplaced their inexperienced color, turned orange — simply as leaves do in autumn — and stopped photosynthesizing.
After 4 weeks of meals deprivation, inexperienced Elysia sea slugs flip orange.
Microscopy revealed that the Elysia’s kleptosomes had begun fusing with lysosomes and that the color change was brought on by the degradation of the chloroplast.
The examine is “exceptional,” says cell biologist Elena Oancea at Brown College in Windfall, Rhode Island. Finding out the molecular and mobile processes of creatures as small as sea slugs is extraordinarily difficult, she says. “It takes plenty of braveness to try this.”
The invention of the kleptosome might assist to reply broader questions on organelle evolution and different mobile processes that we don’t perceive but, Oancea says. All life is constructed on cells, she provides: “It’s the essential precept of nature.”
This text is reproduced with permission and was first revealed on June 25, 2025.
