In an experiment on fruit flies, or black fruit flies, researchers at the University of Pennsylvania found that the addition of different types of microbes to the diet of flies led to genetic change, causing important genetic changes in just five generations.
“Our work strongly suggests how microbial society moves to form, at least in the part where organisms live, and how they evolve,” says Paul Schmidt, a leading biologist and author in Pennsylvania.
“The fact that we can see this effect in experiments conducted in such a short period of time suggests that the magnitude of the physiological effects of microbes is unreliable.”
A setting closer to nature, subject to weather, seasonal changes, and even strange spiders or fleets of dirt-penetrating containers.
The fact that despite the possible effects of these external factors, researchers still found microbiome shifts to have a significant effect on the genome of a fly population, making the discovery more urgent, says Schmidt.
“I think it’s fair to say that we have preserved ecological realism at the expense of significant environmental impacts,” he says.
“We have transformed the relative abundance of these germs into the diet of flies, and it was enough to see an effect.”
The lead author on the paper, Schmidt and his postdoctoral colleague Seth Rodman, took advantage of the fact that flies contain relatively simple microbiome communities compared to other organisms such as humans.
“If you scan microbes for mammals, many of the bacteria you find in the choke are unknown,” says Rodman.
“But this is not the case with flies. It just happens that Drosophila has only 100 species in the microbiological community.”
Other benefits of fruit flies for this type of study include the short time of their generation – one can study several generations over several months – and the fact that they can be reared in extremely high population sizes.
In this case, this meant that each experiment contained hundreds of thousands of flies.
From previous work, scientists have given an indication that microbiome is associated with changes in fly fitness.
Flies from northern latitudes contain more Lactobacillus bacteria as part of their microbiome, live longer, have fewer eggs and are more tolerant to stress.
On the other hand, the most densely populated population, who have an excess of Acetobacter bacteria, have a shorter lifespan, more eggs, and less stress.
Laboratory work revealed that exposing flies to these two types of bacteria gives these similar symptoms.
But can germs stop the growth of whole groups of flies? To test whether Schmidt, Rodman and his colleagues designed an experimental preparation for the treatment of flies microbes.
They have inserted thousands of flies into each of the numerous 2-cubic-meter outer clear cans decorated with floors and a peach tree.
They diversify the nutrients in some packages, supplementing him with Acetobacter or Lactobacillus.
Researchers confirmed that nutrition changed microbium flies, albeit slightly. However, it was enough to influence his genes.
By comparing the genome of the flies with the result at the beginning of the study, five generations later, the team could make different changes in the frequency of some alleles – a type of gene – that was consistent with what was normally observed. Population flies.
“We found that the allele that was most common in lactobacillus cages is also the most common allele in the north, where lactobacillus itself is more common,” says Rodman.
“Alleles that were more common in Alitobacter cages are also more common in the South, where Acetobacter is more common.”
According to the researchers, the importance of the effect of microbes at home was revealed.
“The bottom line is that microbes lead to rapid adaptation,” says Schmidt.
The authors say that whether this effect translates into humans and other animals is important for further study, but many studies have confirmed the powerful effects of microbiome.
In future work, researchers turned on the text, and tested it to see if changes in the genetic profile of flies are affected which could help germs gain a foothold in their microbes.
They will explore more in depth how precisely the variable microbium affects its host.