Tropical Butterflies Use DNA Switch to Adapt Wing Patterns Seasonally
Scientists at the National University of Singapore (NUS) have identified a genetic mechanism that allows tropical butterflies to adjust their wing patterns in response to seasonal temperature changes. This discovery highlights the role of a specific DNA “switch” in the evolution of environmental adaptability among these insects. The findings were published on October 24, 2025, in the journal Nature Ecology & Evolution.
The research, led by Professor Antónia Monteiro from the NUS Department of Biological Sciences, focused on the Bicyclus anynana, a butterfly known for its striking seasonal variations. During the wet season, these butterflies develop larger eyespots on their wings, while in the dry season, the eyespots shrink. This seasonal plasticity aids their survival in fluctuating environments, but the underlying genetic mechanisms have previously remained elusive.
In their study, the team discovered a key gene known as Antennapedia (Antp), which governs the development of eyespots in satyrid butterflies. They found that the activity of this gene varies with the temperature conditions experienced during the butterfly’s development. By disrupting Antp’s activity in different satyrid species, researchers observed a significant reduction in eyespot size, particularly at elevated temperatures. This confirmed the gene’s crucial role in enabling butterflies to adjust their wing patterns seasonally.
Additionally, the research team identified a novel DNA switch, or promoter, that is unique to satyrid butterflies. This switch activates the Antp gene specifically in the cells responsible for the eyespots. When the switch was disabled, the butterflies showed a diminished capacity to alter their eyespot size in response to temperature changes. This finding suggests that the genetic switch has played a significant part in the evolution of seasonal adaptability among these insects.
Dr. Tian Shen, the study’s first author, remarked on the implications of their findings, stating, “It is striking that a simple genetic switch can underlie complex environmental sensitivity across a broad group of insects.” He noted that this research paves the way for future investigations into how such genetic elements contribute to adaptation, offering insights that could be vital for conservation efforts in the face of a changing climate.
As climate change continues to pose challenges to biodiversity, understanding the mechanisms of adaptation in species like the tropical butterfly could inform strategies to enhance resilience among various organisms. The study serves as a reminder of the intricate links between genetics and environmental factors in the natural world.
