Astonishing fact: Viruses and bacteria can pass on their genes to insects 

Nature never to fails to amaze us, isn’t it? A recent development in the field of entomology (scientific study of insects) just proves it all the more. According to a recent study, millions and millions of years have passed since microbes such as viruses and bacteria have given various species of insects an evolutionary edge. How? By passing on their genes (thousands of them) to the insects through a process called ‘horizontal gene transfer’ or HGT. The findings of this research, conducted by a team of evolutionary biologists from the Zhejiang University in China and the Vanderbilt University in the US, have been recently published in the scientific journal called Cell. Here’s what you need to know about horizontal gene transfer and its impact on insects. 

What is HGT all about? 
Sounds pretty complicated, right? The process is not as complex as it sounds though. Also known as lateral gene transfer, HGT is the mechanism of passing genetic materials among unicellular or multicellular organisms. But it’s not the typical transmission of genes through DNA, from parent to offspring. It is quite an important evolutionary force. Surprisingly, it’s more common than you think, especially among microbes. For instance, through this process, bacteria transmit antibiotic-resistance genes to several insect species.  

HGT and its impact on insects 
The findings of this research suggest that there are more than 1400 genes spread across 11 to 19 insect species, such as butterflies and moths that originally grew out of microbes such as bacteria, viruses and fungi as well as plants. As some of you might know, insects evolved almost 479 million years ago and comprise of more than 50 per cent of life on Earth. And, this brand-new study indicates that the movement of genes might have strongly influenced insect evolution. How? By offering them dominant traits such as developing mating behaviour, absorbing nutrition, growth, and adaptation to environmental changes. Earlier, entomologists and evolutionary biologists knew that HGT was largely responsible for insect biodiversity. However, till date, nobody knew the extent of it.  

Unable to decide which gene to start with, considering there are 1400 of them, the team of researchers chose the most prevalent one without any known function in insects. It is known as LOC105383139. The goal, of course, was to validate its function in insects. What they found was fascinating. This gene, transferred horizontally into almost all moths and butterflies, has been existing for more than 300 million years. It has been passed on by a bacterial genus named Listeria.  

Wait, the experiment isn’t over yet. What they found out next was even more astonishing. When they removed the gene from diamondback moths (a pest affecting broccoli and cabbage), they got to know that the moths were unable to produce viable eggs. This reflects that, meaning, LOC105383139 highly affects the male mating behaviour in such moths.  

The team now aims to continue with their research in the hope that they will be able to find out more about insect behaviour as well as use such genes as potential pest-control tools.