麻豆淫院

Researchers from Academia Sinica, Taiwan and the Max Planck Institute for Biology T眉bingen, Germany, have revealed how the nematode gene nhr-66 controls the production of cuticular collagens that enable predatory fungi to adhere and capture their nematode prey.

While reduced collagen expression helps nematodes evade fungal traps, it also weakens their protective cuticle, highlighting an evolutionary trade-off in this microscopic predator鈥損rey interaction. These findings are in the journal PLOS Biology.

Predator鈥損rey relationships are powerful engines in evolution, driving intricate adaptations and counter-adaptations across the tree of life. One of the most fascinating but least visible examples occur in the soil, where carnivorous fungi hunt microscopic worms known as nematodes.

Nematodes, such as the model organism Caenorhabditis elegans, represent the most abundant animal group on Earth. They rely on their outer cuticle, which is rich in diverse collagen proteins, forms a protective layer against environmental challenges, and plays a vital role in maintaining the worm's body structure and shape.

Meanwhile, predatory fungi such as Arthrobotrys oligospora use specialized traps鈥攁dhesive nets鈥攖o physically capture their nematode prey. This situation between two very different organisms offers the unique opportunity to study cross-kingdom predator鈥損rey interaction and adhesion.

Researchers explored this sticky battle from the nematode's side using sophisticated genetic screens. They have shown how the C. elegans gene nhr-66, a transcription factor that regulates the production of key cuticular collagens, acts as the "Velcro" for fungal traps. A loss of normal nhr-66 function leads to reduced collagen expression in nematodes, weakening the sticky bond and allowing nematodes to escape fungal capture.

This finding reveals how nematodes balance the need for a protective cuticle with the risks of predation, highlighting an evolutionary trade-off between defense and physiological integrity.

Sticky survival: How fungi catch their prey

Nematode-trapping fungi like A. oligospora capture their prey by shooting out sticky nets to trap the worms physically. "It is fascinating to see this happen under the microscope鈥攖he fungi trap nematodes almost instantaneously. We were curious as to how that works," says lead researcher Dr. Yen-Ping Hsueh.

By performing forward genetic screens on the model nematode C. elegans, the team identified worms that could escape fungal traps. These resistant strains all had mutations disabling nhr-66, highlighting its pivotal role in this microscopic sticky interaction.

While a downregulation of the nhr-66 gene allows the mutant worms to evade fungal capture, they pay a heavy price: without nhr-66, their cuticles become fragile, making them hypersensitive to environmental stress, such as water exposure.

"What surprised us was how strong this trade-off is," Dr. Hsueh explains. "These resistant mutants essentially have very little chance to survive the natural environment because their weakened cuticle can't handle stress like rainfall."

Broader implications and future directions

Understanding the molecular machinery behind fungal adhesion has practical potential. "If we can fully understand the molecular and biochemical mechanisms of this adhesion, we might be able to develop artificial 'super-glues,'" Dr. Hsueh suggests, with possible applications in biotechnology and pest management.

First author Han-Wen Chang notes, "Learning from how nematodes' cuticles work could inspire new bio-based adhesives in materials science."