A research team from Nagoya University in Japan has utilized artificial intelligence (AI) to determine the role of a protein called piezo in controlling the mating posture of male fruit flies. Previous studies on animal mating have been limited to behavioral observations, leaving gaps in our understanding of this crucial process. In fruit flies, maintaining an effective mating position is vital for reproductive success. The male fruit fly mounts the female and maintains this posture until enough sperm is transferred for fertilization, which occurs approximately eight minutes after copulation initiation.
The researchers identified piezo as a likely candidate involved in maintaining the copulation posture. Piezo is a family of transmembrane proteins found in bristle cells, which are sensitive cells in male genitals. These proteins are activated when mechanical force is applied to a cell membrane, leading to the flow of ions through the channel and generation of an electrical signal. This signal triggers cellular responses, such as the release of neurotransmitters in neurons and the contraction of muscle cells, enabling the fly to sustain its mating position.
To further investigate the neural mechanism behind this phenomenon, the team used a technique called optogenetics. Optogenetics combines genetic engineering and optical science to create genetically modified neurons that can be deactivated using specific wavelengths of light. By silencing the neurons expressing piezo, the researchers could manipulate their activity during mating.
Implementing optogenetics presented a challenge for the team. They needed to ensure that the light was only turned on during mating, but manually controlling the photostimulation was time-consuming and impractical. To address this, they developed an experimental deep learning system that could recognize copulation. By training the AI to detect sexual intercourse, they could automatically control the photostimulation. The AI-driven system revealed that inhibiting piezo-expressing neurons caused males to adopt an improper mating posture, resulting in reduced reproductive performance.
The researchers concluded that the piezo gene plays a critical role in enabling male fruit flies to adjust their axis in response to the female, maximizing mating success. Piezo proteins are known to be involved in various physiological processes, such as touch sensation, hearing, blood pressure regulation, and bladder function. This study adds reproduction to the list of functions influenced by piezo proteins.
Professor Azusa Kamikouchi, Assistant Professor Ryoya Tanaka, and student Hayato M. Yamanouchi led the research at Nagoya University. Kamikouchi expressed enthusiasm for the use of AI in such studies, emphasizing the advancements in experimental systems and analysis methods made possible by informatics. The team’s work not only contributes to understanding the reproductive system of animals but also paves the way for investigating neural mechanisms controlling behavior in other species. The established method has the potential to significantly advance neurobiological research.
Source: Nagoya University