Scientists have uncovered that thousands of proteins found in seven different aphid species share a common structural blueprint, even though these proteins evolve very quickly to help aphids manipulate plants and avoid their defenses. Published in the Proceedings of the National Academy of Sciences on September 2, 2026, the study introduces a group of these proteins called BICYCLE proteins, which contain a repeating pattern of a chemical component called cysteine and a structural feature known as a saposin-like fold. These proteins are used by aphids to alter plant DNA and create galls—specialized growths that serve as both shelter and food for their young. The research, led by David Stern of the Stowers Institute for Medical Research and involving Angela Gronenborn from the University of Pittsburgh, revealed that BICYCLE proteins evolve at an unusually fast pace. This rapid evolution makes them challenging to study with traditional methods, as their genetic sequences change so quickly that standard databases cannot easily identify similarities between them. This fast evolution suggests an ongoing "arms race" between aphids and the plants they attack, with each side continuously adapting to outmaneuver the other. To better understand the structure of BICYCLE proteins, the team used AlphaFold2, an artificial intelligence system designed to predict protein structures based on their genetic sequences. However, AlphaFold2 initially struggled to produce accurate predictions because it lacked the evolutionary context needed to understand these rapidly changing proteins. To overcome this, the researchers collected aphids from different regions, sequenced their genomes, and provided AlphaFold2 with this evolutionary information. This allowed the AI to generate precise models of the BICYCLE proteins' structures for the first time. Although all BICYCLE proteins share a common structural motif, the study found significant differences in their surface chemistry and functional properties. The researchers could not identify any consistent features that suggest a shared function. This implies that the BICYCLE proteins may use a variety of different mechanisms to manipulate plant cells and avoid detection by the plant's immune system. The discovery of BICYCLE proteins opens new possibilities for studying other rapidly evolving proteins involved in immunity and interactions between hosts and parasites. This research could provide important insights into agricultural challenges, such as how to better protect crops from insect pests, and deepen our understanding of biological evolution. The team notes that this study is just the beginning of their work on how insects like aphids influence plant biology through these unique proteins.