Ice Bucket Challenge Reveals Bacteria Can Anticipate Seasons

Researchers have discovered that bacteria utilize internal 24-hour clocks to anticipate seasonal changes, reports Science Daily. This revelation stems from investigations involving an 'ice bucket challenge.' The findings suggest important implications for how circadian rhythms support adaptation in various species amid climate change.

Experimental Design and Findings

The research team exposed populations of blue-green algae, also known as cyanobacteria, to varying artificial day lengths while maintaining a constant warm temperature. They used different light configurations — short days, equinox days (equal light and dark), and long days — over eight days. Following this exposure, samples underwent immersion in ice for two hours, and their survival rates were closely monitored.

Surprisingly, cyanobacteria that experienced multiple short days (eight hours of light followed by 16 hours of darkness) demonstrated survival rates of 75%. This figure is three times higher than those unprimed for cold. Exposure to only one short day failed to enhance cold resistance. Instead, survival chances improved significantly after six to eight short days.

Photoperiodism's Role in Survival

Cyanobacteria with genes responsible for their biological clock removed showed similar survival rates across all day lengths. This finding highlights the vital role of photoperiodism — the ability to measure the day-night cycle — allowing bacteria to adapt physically in anticipation of new seasons and climate variability.

Dr. Luísa Jabbur, the study's first author, noted that these bacteria can gauge day length; when short days accumulate, they alter their physiology to prepare for winter challenges. This underscores the adaptations bacteria make using their internal clocks.

Implications and Future Research

The Johnson laboratory has a rich history of research into the circadian rhythms of cyanobacteria. Previous studies support the idea that bacteria possess a sort of biological clock, granting them the ability to differentiate between varying lengths of day and night, thus providing an evolutionary advantage.

This recent research is the first to demonstrate that bacteria have developed photoperiodism to predict seasonal cues. These findings open new avenues of scientific inquiry. A significant question arises: how can organisms with lifespans of six to 24 hours evolve mechanisms to foresee future environmental changes?

Dr. Jabbur emphasizes the concept of bacteria signaling to their progeny, ensuring they are prepared for changing conditions.

Investigating Molecular Memories

As part of her BBSRC Discovery Fellowship at the John Innes Centre, Dr. Jabbur will explore how other species might develop similar photoperiodic responses, especially in agricultural contexts impacted by climate change. This research will delve into molecular memory systems that may transfer information generation to generation.

Investigation will focus on whether accumulated compounds during nights of short days function as molecular triggers, leading to a physiological shift.

Personal Journey of Discovery

For Dr. Jabbur, this study represents a significant early-career achievement, especially following initial doubt from her mentor, Professor Carl Johnson. His encouragement propelled her to pursue this unique experimental challenge.

Dr. Jabbur recalls an amusing encounter with Johnson, noting his laughter from the Nashville Symphony Chorus resonating throughout the department when she first proposed the icy challenge. His encouragement included a motivational reminder about the importance of innovative research that diverges from conventional wisdom.

Upon successful results from her experiments, Dr. Jabbur experienced a profound sense of discovery. Knowing unique insights about bacterial behavior, she relished in the exclusive knowledge gathered during her research efforts.

Earlier, SSP reported that digging holes at the beach can be dangerous.