Fungal pathogens may be dangerously adapted to global warming: ScienceAlert

If you have ever played a video game the last of us, or watched any of the recent TV adaptations, you’ll be familiar with the idea of ​​a mutated fungus infecting most of humanity—and now there’s some science to match that science fiction.

While we are not on the verge of a social apocalypse as depicted. the last of usResearchers have demonstrated how pathogenic fungi can evolve in warmer climates to better cope with the heat inside our bodies.

Given that heat does most of the work that protects us against these threats, the implication is that these pathogens may become a greater threat in terms of disease as they adapt to an ever-warming planet.

“These are not infectious diseases in the infectious sense; we don’t transmit fungi to each other,” says Asia Gusa, a molecular geneticist and microbiologist at Duke University School of Medicine in North Carolina.

“We breathe in fungal spores all the time and our immune system is equipped to fight them off.”

The team looked in detail at the pathogenic fungus Cryptococcus deneoformans, placing it under laboratory conditions and raising its temperature from 30 °C (86 °F) to 37 °C (98.6 °F). These heat stresses significantly altered the genetic landscape of fungi.

In particular, there was more movement in ‘jumping genes’, those transposable elements within DNA that can change positions in the genome – five times more movement at higher temperatures, in fact. While these transposable elements do not make proteins directly, they can affect the way other genes work.

Three jumping genes in particular were tracked: T1, Tcn12, and Cnl1. The changes they made to genes and within the genome suggested they could alter the way genes are coded, and possibly introduce drug resistance. It is not yet entirely clear what the end result of this increased activity might be.

Further tests were carried out in mice, where the activity of transposable elements was more pronounced. The researchers think that actually being in the animal, along with its immune response and other processes, may be increasing the movement.

“We saw evidence that all 3 transposable elements were mobilized in the fungal genome within 10 days of infecting mice,” says Gusa.

“These mobile elements are likely to contribute to adaptation to the environment and during transition. This may happen more quickly because heat stress accelerates the number of mutations.”

It’s not time to build an underground bunker yet: this research is still in its infancy and doesn’t involve real humans. What’s more, fungal spores are usually larger than viruses, so precautions like face masks will be more effective against them.

Research shows that increased heat causes faster genetic changes C. deneoformans. The takeaway is that dangerous fungi can evolve faster than we think as temperatures around the world rise.

The next step is to study pathogens from people who have relapsed fungal infections. This type of infection already kills hundreds of thousands of people per year, but now it is only a serious immune-compromising risk. That may begin to change one day, and Anger acknowledges the same theme the last of us.

“This is exactly the kind of thing I’m talking about – minus the zombie part!” Anger says. “Fungal diseases are on the rise, mainly due to an increase in the number of people with weakened immune systems or underlying health conditions.”

Research has been published in PNAS.

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