Warns of sticky and cunning genetic weapons of the carnivorous fungus.
Carnivorous Fungi
Carnivorous fungi live in the soil and primarily feed on decaying organic matter. However, this can change quickly if they find themselves deprived of nutrients or detect enticing nematodes nearby. In this case, they enter a carnivorous mode.
Changes in Genetic Activity
Lin and his colleagues wanted to see what happens when fungi, suffering from nutrient deprivation, are exposed to the nematode Caenorhabiditis elegans. The fungi showed a significant increase in DNA frequency when they sensed the nematodes. This led to the presence of additional copies of the genome in the trap cells. The trap cells are located in the fungal hyphae and produce a specialized adhesive for nematodes, allowing these hyphae to stick to the worm once it is caught in the traps.
Trap Formation
One of the most crucial genetic actions that helps the fungi create traps from hyphae is ribosome formation, which enables increased protein production. Ribosomes are the site where proteins are made, so their formation (literally creating more ribosomes) controls cell growth and also determines the amount of protein synthesized.
Specialized Trap Proteins
A new set of proteins has also been identified, now known as trap-expressed proteins (TEPs), which were the most produced proteins in the fungal trap cells. These proteins appear to contribute to the function of the traps rather than their formation.
Other Genetic Activities
No changes in the activity of other genes were observed until the worm was caught. Once the nematode C. elegans enters the traps prepared by A. oligospora with a sticky network of hyphae, the team noted an increase in the production of proteins that weaken the prey. These proteins are capable of manipulating the cells of their prey so that those cells function differently, providing a way for the fungus to penetrate the cell and take control of it. The fungus then uses proteases to digest the nematodes that get stuck in its hyphae.
Effect of the Adhesive on Worms
The adhesive produced by the fungus, now believed to be closely related to TEP proteins, may not affect humans but acts as a strong glue for the worms, binding the hyphae to their flesh. They have no way to escape from the state of being alive while being consumed.
New Discovery
This experiment may be horrifying for the nematodes involved, but it was a discovery for Lin’s team. They have now identified a whole new set of genes that make the fungus traps work. Their results can be compared to the gene activity of other pathogenic fungi, including those that destroy crops, so an improved generation of antifungal agents may one day be influenced by this microscopic horror show.
Source: PLOS Biology, 2023. DOI: 10.1371/journal.pbio.3002400
Reader comments: 41
Elizabeth Raine is a being who writes. Her work has appeared on SYFY WIRE, Space.com, Live Science, Grunge, Den of Geek, and Forbidden Futures. She lurks outside New York City with her parrot, Lysette. When she’s not writing, she either shapeshifts, paints, or embodies a character no one has ever heard of. Follow her on Threads and Instagram @quothravenrayne.
Advertisement
Ars Technica Channel
Previous Story | Next Story
Related Stories
Today in Ars
Fungi Nutrition – What turns a mushroom-feeding fungus into a killer?
Elizabeth Raine – December 18, 2023, 6:23 PM UTC
Enlarged image / Fungal feast. Pishou Adikari, Brigham Young University
Reader comments: 41
Some of the most terrifying monsters are small. The carnivorous fungus Arthrobotrys oligospora doesn’t seem like much when it’s consuming decayed wood. But when it senses the presence of a living worm, it will snatch its prey and consume it alive – pure nightmare fuel.
Until now, not much has been known about how the deadly fungal attack occurs at the molecular level. Researchers from Seneca Academy in Taiwan have finally discovered how the genetic activity of the fungus changes when nematodes get close to A. oligospora. The research team, led by molecular biologist Hong-Chih Lin, found that the fungus creates a kind of adhesive for the worms and additional trap proteins to secure its meal. The fungus then produces enzymes that break down the worms so it can start enjoying its food.
The fungus
The carnivore lives in the soil and primarily relies on feeding on decaying organic matter. However, this can quickly change if it finds itself deprived of nutrients or feels the presence of an enticing nematode nearby. In this case, it enters into a carnivorous mode.
Lin and his colleagues wanted to see what happens when a fungus, suffering from nutrient deficiency, encounters the nematode Caenorhabditis elegans. The fungus showed a significant increase in DNA activity when it sensed the nematodes. This led to additional copies of the genome in the trap cells. The trap cells are located in the fungal hyphae, which produce a specialized adhesive for the worms, allowing these hyphae to stick to the worm once it is caught in the traps.
Perhaps the most important genetic actions that help the fungus create traps from hyphae are ribosome formation, which enables increased protein production. Ribosomes are where proteins are made, so their formation (literally creating more ribosomes) controls cell growth and also determines the amount of protein synthesized.
A new set of proteins, now known as trap-exuded proteins (TEPs), has also been identified, which were the most produced proteins in the fungal trap cells. These proteins seem to contribute to the function of the traps rather than their formation.
No changes were observed in the activity of other genes until the worm was captured. Once the nematode C. elegans enters the traps prepared by A. oligospora with a sticky network of hyphae, the team noted an increase in the production of proteins that weaken the prey. These proteins are capable of manipulating the prey’s cells so that those cells behave differently, providing a way for the fungus to infiltrate and take control of the cell. The fungus then uses proteases to digest the nematodes that are attached to its hyphae.
The adhesive produced by the fungus, which is now believed to be closely related to TEPs, may not affect humans but acts as a strong glue for worms that binds the hyphae to their flesh. They have no way to escape from this state of living consumption.
While this experience may be horrifying for the nematodes involved, it was a discovery for Lin’s team. They have now identified a whole new set of genes that make the fungus’s traps function. Their results can be compared with gene activity from other pathogenic fungi, including those that destroy crops, so a future generation of antifungal agents may someday be influenced by this microscopic horror story.
Source: PLOS Biology, 2023. DOI: 10.1371/journal.pbio.3002400
Reader comments: 41
Elizabeth Raine is a creature of writing. Her work has appeared in SYFY WIRE, Space.com, Live Science, Grunge, Den of Geek, and Forbidden Futures. She lurks outside New York City with her liszt parrot. When she isn’t writing, she may be shapeshifting, painting, or embodying a character you’ve never heard of. Follow her on Threads and Instagram @quothravenrayne.
Advertisement
Ars Technica Channel
Previous story | Next story
Related stories
Today in Ars
Source: https://arstechnica.com/science/2023/12/tracking-the-genes-that-turn-a-fungus-into-a-carnivore/
Leave a Reply