New scientific discovery! A guide to the parasites of the "poison king" of bat flies

Produced by: Science Popularization China

Author: Keke (popular science creator)

Producer: China Science Expo

In nature, the complex interactions between organisms have always been a subject of tireless exploration by scientists. Among them, parasitic relationships have attracted much attention due to their uniqueness and potential ecological impacts. Among the many parasitic organisms, there is a special insect - the bat fly, which is not only an obligate parasite of bats, but may also play an important role in the transmission of pathogens.

Recently, scientists from the Institute of Zoology, Chinese Academy of Sciences, conducted in-depth research on bat flies, revealing the adaptive evolution mechanism of this mysterious creature and its potential role in the spread of pathogens, opening a new window for us to understand the microscopic world.

The uniqueness of bat flies: an evolutionary miracle of adaptation to parasitic life

Bat flies are a type of insect that parasitizes on the bodies of bats. Their survival is completely dependent on their host bats. Long-term co-evolution has led to significant adaptive changes in bat flies in both morphology and physiology. Through comparative genomics analysis, researchers have discovered a series of characteristic genes related to bat flies' adaptation to parasitic life.

These genetic changes reveal some key adaptations in bat flies' evolution. First, bat flies lost their eyes and wings, reflecting their abandonment of the ability to fly, as living on the surface of their hosts no longer requires these organs. Instead, bat flies evolved long, sturdy legs that allow them to better navigate through the thick hair of bats.

In addition, the study found that the genes related to vision, flight and circadian rhythm of bat flies have changed . These changes indicate that bat flies have made deep adjustments to adapt to the living habits of bats. For example, bats are mostly nocturnal animals, and bat flies may have adjusted their biological clocks accordingly to keep pace with the activity cycle of the host. These findings not only reveal the adaptive evolutionary mechanism of bat flies, but also provide valuable references for our understanding of the evolutionary process of other parasites.

Weird-looking bat flies hide in bat hair

(Image source: Wikipedia)

Bat flies: secret carriers of viruses

In addition to adaptive evolution, this study also revealed the important role that bat flies may play in the spread of pathogens. Through small RNA (sRNA, a general term for RNA molecules with a length of less than 200 nucleotides) sequencing technology, researchers found a variety of known and newly classified viruses in bat flies, including positive-strand RNA viruses, negative-strand RNA viruses, double-strand RNA viruses, and DNA viruses. This discovery shows that bat flies are not only carriers of a single virus, but also a "mobile reservoir" of multiple viruses.

The fact that bat flies carry such a diverse array of viruses has scientists wondering why these tiny insects are able to host so many different viruses.

This may be closely related to the bat fly's lifestyle . As an obligate parasite of bats, bat flies maintain close contact with bats for a long time, and bats themselves are the natural hosts of many viruses. This close relationship provides ideal conditions for the spread of viruses from bats to bat flies.

Even more surprising is that the study found that bat flies can not only suck the blood of bats, but also the blood of other mammals. This discovery suggests that viruses carried by bats may be transmitted to other hosts through bat flies as an "intermediary." This potential cross-species transmission pathway provides us with a new perspective to understand the transmission mechanism of certain diseases, and also warns us that we need to pay more attention to the important role of these seemingly insignificant creatures in the disease ecosystem.

The common long-eared bat, a common host of bat flies, is widely distributed in northern China.

(Image source: Wikipedia)

RNA interference: the molecular mechanism of the game between bat flies and viruses

While revealing that bat flies carry a variety of viruses, the researchers also delved into how bat flies coexist with these viruses. They found that the RNA interference pathway plays a key role in the diversity and evolution of viruses in bat flies.

RNA interference is an important gene regulation mechanism in organisms and an important line of defense against viral infection.

Studies have found that the RNA interference pathway of bat flies can affect the replication and evolution of viruses . This means that bat flies do not passively accept the invasion of viruses, but are engaged in a continuous "arms race" with viruses through their own immune mechanisms. On the one hand, the RNA interference pathway helps bat flies control the number of viruses in their bodies and prevent excessive reproduction of viruses that lead to the death of the host; on the other hand, this mechanism also puts selection pressure on viruses, prompting them to continue to evolve in order to evade the host's immune surveillance.

This complex interaction mechanism not only explains why bat flies can carry multiple viruses at the same time without being killed by the viruses, but also provides new insights into our understanding of the evolution of viruses. This discovery has important implications for studying the interactions between other vectors and pathogens, and may provide new ideas for future disease prevention and control strategies.

The neosome of a new species of bat fly

(Image source: Reference 2)

New methods open up new horizons: the establishment of a non-model vector species research platform

In this study, researchers not only made rich scientific discoveries, but also established a research platform for non-model vector species (i.e., uncommon vector species), providing powerful tools for studying unconventional research objects such as bat flies. Traditionally, most pathogen transmission research focuses on common vectors such as mosquitoes and ticks, while special vectors such as bat flies are often overlooked.

However, these seemingly insignificant organisms may play a key role in the transmission chain of certain diseases. New research platforms provide us with a deeper understanding of these non-model vector species, which will help us to more fully understand the ecological networks of disease transmission.

For example, through this platform, researchers can simulate the process of bat flies sucking blood and spreading viruses under laboratory conditions and observe the dynamics of virus transmission between different hosts. This method can not only help us understand the specific role of bat flies in virus transmission, but also provide important basis for predicting and preventing potential disease outbreaks.

In addition, the establishment of this research platform also provides a model for other similar non-model organism studies. It demonstrates how to apply advanced molecular biology techniques to species that are traditionally difficult to study, opening up new possibilities for ecological and epidemiological research.

Conclusion

This study on bat flies not only reveals the evolutionary secrets of this special insect, but also provides a new perspective for us to understand the complex host-parasite-pathogen interaction system. It reminds us that in nature, even the smallest organisms may play an important role in ecosystems and disease transmission. With the deepening of research, we may be able to better predict and prevent potential disease threats and protect human health.

References:

1.Guangping Huang et. al., Adaptive Evolution of Traits for Parasitism and Pathogen Transmission Potential 2 in Bat Flies

2.Haoran Sun et. al., Ascodipteron sanmingensis sp. nov., a new bat fly (Hippoboscidae: streblid grade) from Fujian, China