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A Col­lec­tion of News by Moos


201723Apr13:14

Naked mole-​rats turn into plants when oxy­gen is low

Infor­ma­tion
pub­lished 23 April 2017 | mod­i­fied 23 April 2017
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Naked mole-ratsDeprived of oxy­gen, naked mole-​rats (Het­e­ro­cephalus glaber) can sur­vive by metab­o­liz­ing fruc­tose just as plants do, researchers report this week in the jour­nal Sci­ence. Under­stand­ing how the ani­mals do this could lead to treat­ments for patients suf­fer­ing crises of oxy­gen depri­va­tion, as in heart attacks and strokes.

This is just the lat­est remark­able dis­cov­ery about the naked mole-​rat, a cold-​blooded mam­mal that lives decades longer than other rodents, rarely gets can­cer, and doesn’t feel many types of pain,” says Thomas Park, pro­fes­sor of bio­log­i­cal sci­ences at the Uni­ver­sity of Illi­nois at Chicago (UIC), who led an inter­na­tional team of researchers from UIC, the Max Del­brück Insti­tute in Berlin and the Uni­ver­sity of Pre­to­ria in South Africa on the study.

In humans, lab­o­ra­tory mice, and all other known mam­mals, when brain cells are starved of oxy­gen they run out of energy and begin to die. But naked mole-​rats have a backup: their brain cells start burn­ing fruc­tose, which pro­duces energy anaer­o­bi­cally through a meta­bolic path­way that is only used by plants – or so sci­en­tists thought.

In the new study pub­lished on 21 April, the researchers exposed naked mole-​rats to low oxy­gen con­di­tions in the lab­o­ra­tory and found that they released large amounts of fruc­tose into the blood­stream. The fruc­tose, the sci­en­tists found, was trans­ported into brain cells by mol­e­c­u­lar fruc­tose pumps that in all other mam­mals are found only on cells of the intestine.

The naked mole-​rat has sim­ply rearranged some basic building-​blocks of metab­o­lism to make it super-​tolerant to low oxy­gen con­di­tions,” said Park, who has stud­ied the strange species for 18 years.

At oxy­gen lev­els low enough to kill a human within min­utes, naked mole-​rats can sur­vive for at least five hours, Park said. They go into a state of sus­pended ani­ma­tion, reduc­ing their move­ment and dra­mat­i­cally slow­ing their pulse and breath­ing rate to con­serve energy. And they begin using fruc­tose until oxy­gen is avail­able again. The naked mole-​rat is the only known mam­mal to use sus­pended ani­ma­tion to sur­vive oxy­gen deprivation.

The sci­en­tists also showed that naked mole-​rats are pro­tected from another deadly aspect of low oxy­gen – a build-​up of fluid in the lungs called pul­monary edema that afflicts moun­tain climbers at high altitude.

The sci­en­tists think that the naked mole-​rats’ unusual metab­o­lism is an adap­ta­tion for liv­ing in their oxygen-​poor bur­rows. Unlike other sub­ter­ranean mam­mals, naked mole-​rats live in hyper-​crowded con­di­tions, packed in with hun­dreds of colony mates. With so many ani­mals liv­ing together in unven­ti­lated tun­nels, oxy­gen sup­plies are quickly depleted.

(Source: Uni­ver­sity of Illi­nois at Chicago news release, 20.04.2017)


UN Biodiversity decade

Goal: 7000 tigers in the wild

Tiger range countries map

Tiger map” (CC BY 2.5) by Sander­son et al., 2006.

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