The idea that the insect genome is relatively small and less complex can go straight to the trash.
The Siberian clapper grasshopper (Bryodemella tuberculata) is one of the most striking locusts of Central Europe. And not only because of its remarkable appearance. Researchers have succeeded in mapping his genome. And it turns out that this locust has a bizarrely large genome; the largest of the entire insect kingdom.
More about the Siberian clapper locust
The Siberian clapper grasshopper is a rare animal. In northwestern Europe, the species has declined sharply, making it almost extinct. At the moment you can only find it in a small number of populations on the banks of the rivers in the Alps. These endangered habitats have been created through thousands of years of constant change due to the natural dynamics of the rivers. The grasshopper owes its name to the loud flapping sound it can make.
In a new study, published in the journal PLOS ONE, researchers examined the genomes of 50 different locust species. They then measured the genomes using flow cytometry (a technique for counting and studying microscopic particles in a flowing liquid). And one of the locusts the researchers examined was the Siberian clapper locust.
Largest genome
The findings show that the Siberian clapper locust harbors a remarkably large genome, consisting of a whopping 21.48 billion base pairs. Its genome is not only the largest of all insects, it is even seven times larger than our own genome (which consists of about three billion base pairs). The grasshopper thus knocks the grasshopper Deracantha onos, the former record holder, off the throne.
Incorrect
The discovery turns everything we thought we knew about insect genomes on its head. That’s because scientists assumed that the insect genome would be relatively small and less complex. But that assumption turns out to be quite wrong. “We now see that genome size is not necessarily related to the complexity of an organism,” said researcher Oliver Hawlitschek. The only question is: why does the locust have such a record-breaking genome? “The species easily adapts to different environmental conditions,” Hawlitschek explains. “This may have promoted genetic diversity and led to the exceptionally large genome.”
Size of taken
The size of genomes varies considerably between different groups of animals – and sometimes even within groups. For example, most insect genomes are much smaller than those of the Siberian clapper grasshopper. Take the fruit fly, for example. Its genome is no more than one-sixth that of the human genome. Scientists have long been searching for the reason behind this remarkable variability. But there is still a long way to go. The size of the genome has been unraveled in only 1,345 of the more than one million known insect species. But what we do know in the meantime is that locusts and crickets generally have the largest genomes.
The study provides more insight into the variation in genome size in locusts. Although there is still plenty to discover. In follow-up research, Hawlitschek wants to use detailed sequence-based genomic analyzes to learn more about the evolutionary mechanisms that determine the size of genomes. And not just to expand our knowledge about genome size in insects. Because the results may also have consequences for ourselves. “I am convinced that studying these extremes will also provide us with many insights into the function of the human genome,” concludes Hawlitschek.