Several species in the animal kingdom use curious strategies to attract partners. Bees, for example, dance, while fireflies emit light. A new study, published in March this year, showed that females of a species of moth may have the most unusual way of attracting partners: they use a poison present in a plant.
The research investigated how bella moths (Utetheisa ornatrix) evolved to use plant toxins sunn hemp , which are consumed during the caterpillar stage, to attract potential mates. These same toxins (known as pyrrolizidine alkaloids ) are used to protect themselves (and, subsequently, their eggs) against predators. The results were published in the scientific journal PNAS.
The leaves and seeds of sunn hemp are loaded with a particular type of bitter-tasting toxin and, despite being avoided by some animals — the toxin is among the main causes of accidental death in cattle — it is a food source for the bella moth. How the species developed the ability to feed on a toxin that can be fatal to other animals is still unknown to researchers.
Therefore, in the new study, scientists sequenced the bella moth genome to identify specific genes that could confer immunity to these toxins. They also sequenced the genomes of 150 museum specimens to determine the origin of bella moths and their close relatives.
“We were able to show that it is possible to use museum specimens to answer genetic questions that normally require complicated laboratory techniques,” said study co-author Andrei Sourakov, collections coordinator at the McGuire Center for Lepidoptera and Biodiversity at the Florida Museum of Natural History. in a statement. “This opens a window for future research of this type.”
Researchers found that when these moths are ready to mate, females release a cloud of aerosolized alkaloids (toxins) derived from the plants they ate when they were still caterpillars. Males are attracted to this scent and follow it to its source. .
When they find their potential mate, male moths perform a short, elaborate ritual in which they gently touch the female's head with two retractable dandelion-like structures. Each strand of these structures is mixed with pyrrolizidine alkaloids.
If the female decides that the male has sufficient quantity and quality of these toxins, the pair will mate. At the end, the male releases a substance called spermatophore, which contains sperm and more alkaloids. The female uses the spermatophore to infuse the toxins into the eggs resulting from mating, protecting them from predators.
How do moths not poison themselves with toxins?
Bella moths are able to avoid the harmful effects of pyrrolizidine alkaloids by using an enzyme that oxidizes the molecule, rendering it harmless. However, if a predator eats a moth, the process is reversed and the alkaloid regains its poisoning potential.
Researchers in the current study wanted to understand how bella moths acquired this special enzyme. They discovered that the species contains two copies of the gene that codes for this toxin. The scientists' theory is that bella moths acquired the second copy through a process of genetic duplication, the same from which other species, such as plants, developed new characteristics.
The research also found two copies of a gene that is partially involved in the production and defense of antioxidants. Sourakov says he believes these genes may be related to both the bella moths' ability to detoxify alkaloids and their longevity — this species can live up to 50 days, which is four to five times longer than the average moth, according to the researcher.
“Certain types of stress on biological systems result in longer lifespan. It could be that the interaction that Bella moths have with alkaloids is not only the reason why it makes sense for them to live long lives, but also one of the mechanisms behind it,” says Sourakov.
Source: CNN Brasil
Charles Grill is a tech-savvy writer with over 3 years of experience in the field. He writes on a variety of technology-related topics and has a strong focus on the latest advancements in the industry. He is connected with several online news websites and is currently contributing to a technology-focused platform.
