Every summer, fireflies become “famous” in the night sky with their strange bioluminescent displays, showcasing a range of colors – green, yellow, orange, and even blue.
Scientists have identified over 2,000 species of fireflies, each with its own unique blinking light pattern and differently shaped light-emitting organs.
But have you ever wondered how these glowing insects accomplish this? Scientists have certainly asked themselves this question—and they have discovered two important genes that grant fireflies this special “ability.”
(Source: National Geographic).
“There are ‘two gems’ in firefly research” – Xinhua Fu, a biologist at Huazhong Agricultural University in China, stated.
- The first is how firefly larvae rapidly develop their light-emitting organs into a completely different physical structure as they mature.
- The second is how adult fireflies can precisely control these organs—often referred to as “lanterns”—for instance, blinking in “patterns” similar to Morse code when their alluring mates are nearby.
In a study published in the journal Nature Communications, Fu and co-author Xinlei Zhu decoded the genome of the Aquatica leii, a species of firefly found in rice paddies in China.
They focused on two key genes responsible for the formation, activation, and positioning of the fireflies’ light-emitting organs: Alabd-B and AlUnc-4.
This was surprising because these genes were already known to aid in firefly development, but they had never been linked to the phenomenon of bioluminescence.
Fu noted that this discovery could ultimately help scientists understand how these beetles evolved their ability to glow like fireworks.
Fu also emphasized the importance of this work, as firefly populations are currently “free-falling” globally. Eighteen species are currently facing extinction in the United States, with many others worldwide at similar risk due to light pollution, pesticide use, habitat loss, and other factors.
The Secret of the “Blinking” Light
It turns out that the species of firefly in this study is one that Fu particularly loves: “He discovered this species and has been studying it since 2000, even raising a colony of fireflies in the lab—producing up to 600,000 fireflies each year.”
This population allows him to enhance research on the precise 24-hour timeframe immediately following pupation, which is when their mature light-emitting organs develop.
(Source: The New York Times).
In an experiment this year, Fu and Zhu began editing the gene sequences of these insects to observe the effects produced when certain genes were “turned off” or removed.
They found that during the pupation process, fireflies activate the Alabd-B and AlUnc-4 genes, causing the “lanterns” to develop in the correct positions within their abdomens.
Jing-Ke Weng, a biochemist and Director of the Plant-Human Interface Institute at Northeastern University in Boston, described this research as “impressive” for utilizing advanced tools and genome analysis.
Weng stated that this study lays the groundwork for understanding how the common ancestors of fireflies integrated these two genes for bioluminescence.
However, significant challenges remain to expand evolutionary research—partly due to their complex “courtship” behaviors. Raising fireflies is much more challenging than breeding mice, fruit flies, or other common research animals.
Moreover, this research is limited to the males of one species, A. leii, meaning this pathway has yet to be explored in the other half of the population—the females. Fu plans to address this in a subsequent study.
