The virus is a mysterious thing. The virus can attack all the organisms that have life. The virus attack people, animals, birds, fish, invertebrates, fungi, protozoa, even bacteria.
It’s hard to be easily understood about the virus itself as being living organisms or inanimate. Viruses are such an existence that multiply in certain living cells but behave like inanimate substances outside the cell. That is why it is not advisable to consider the virus as the living cells and the inanimate substances.
I do not want to talk about it and came to the original context.
In October 2016, a great and exciting study was published in the famous journal named “Nature”. The essence of the research is that a gene domain of spider is available in the virus. It is not new to those who have studied or researched the virus, because many viruses steal the DNA of the infected organism. However, this study is important because this virus does not attack the spider or attacks other invertebrates (spider invertebrates). Rather the virus attacks the bacteria.
So, how did the virus steal spider genes? Scientists do not even know, but they have some possibility. Let’s hear the story of the theft.
In the beginning, let’s say a few characteristics of the virus. To understand the virus, it is important to know about cells because the virus attacks the cells. Depending on the number of cells, the animals can be divided into two groups. 1. Multicultural (e.g. humans) 2. Unicellular (e.g.: bacteria)
Two types of cells are on the basis of the presence of cell membrane:
All the multicellular are the Eukaryotic. There are some unicellular creatures who are Eukaryotic (such as Amoeba/, Paramecium). Most unicellular are prokaryotic. These prokaryotic are mainly bacteria and archaea. Archaea is the only one who is close to bacteria (but not bacteria) but they are close to protein from their DNA or near RNA formation.
The virus attacks the branches of all life such as; 1. Eukarya, 2. Bacteria, 3 Archaea. But viruses are usually species-specific. That is, the virus that attacks one species does not attack any other species. For example, the virus that attacks humans does not attack cows. Of course, sometimes the virus comes from other animals to human, it is called zoonosis. About this matter, I will discuss in another article. But until now, I realized that the virus that attacks the bacteria does not attack the eukaryotes. Again, the virus that attacks eukaryotes does not attack bacteria.
The genome sequencing of the bacteriophage W.O. virus reveals that this virus attacks the bacteria called Olbakia. From genome sequencing, how much of the animal is related to any other animal. After sequencing of Bacteriophage W.O. Researchers found that there is a domain of poison /toxin of the spider in the DNA of the virus.
Black Widow Spider:
The spider’s name is Black Widow (Black-Widow). It is named after it because, after the sexual intercourse, the female spider kills male spiders. Their bites are too terrible that they introduce a toxin in the body of the male spider. The name of the toxin is Latrotoxin. People experience vomiting, pain, muscle stiffness, sweating from the intoxication of this poison. The female spider is more dangerous because they are large in size and they contain large venom in the body (female spider is terrible for humans). These spiders are found almost everywhere in the world. Spider story can be told another day. The point is, the domain of the toxin of the spider is found in the DNA of the virus.
If you know a little about Wolbachia bacteria then you could understand how the virus stole the gene. Wolbachia is a bacterium that infects the species of Arthropod (such as mosquito, spider, cockroach, butterfly, bee, cucumber, shrimp, cucumber, etc.) and some nematodes. The interaction of the bacteria with the host is complicated and in many cases, it may be symbiotic. For some cases, this bacteria also help the hosts in reproduction and even survival.
See more: Ten phages that cause human disease
Bacteriophage means that viruses infect bacteria and multiply within bacteria. It usually has a head, tail and base plate. Sometimes there are some parts like some spikes. They have DNA on their heads. The whole body is made of proteins. Bacteriophage can never attack or infect a eukaryotic cell. The reason is that it does not have the ability to attack or infect the genus. Bacteriophage WO is specific to infect the Wolbachia bacteria.
The EAM (Eukaryotic Association Module) is derived from the whole genome sequencing of bacteriophage. The eukaryotic association module is the part of the genome named by the researchers, in which they found the genes to be related to eukaryotic genes. Then the entire genome is reversed to insert into the genome of Olabakia (it is called prophase). It was done to prove the ability of bacteriophage to insert its own genome into the bacterial genome. It proves that the genome that has been inserted in the bacterium has the ability to form.
Then, by analyzing the genome, the bacteriophage genome has only 17 protein domains and bacterial chromosomes have only two protein domains – these protein domains are eukaryotic protein domain. Note that in this case, the genome analysis has been done only in viruses and bacteria. There is a probability to have a match of the eukaryotic genome with the genome of bacteria. Because Olbacia bacteria attack the eukaryotes.
The latrotoxin is a toxin made from Black Widow Spider, for which she is terrible. What is this gene doing in bacteriophage? Because bacteriophage does not attack the spider. You know that bacteria or viruses do not have any wrong thing in their genome, putting something in vain is a threat to their own existence.
Now, from the protein sequence of this toxin, the researchers wanted to find out the species of spider poison that contain this protein. They found the Black Widow spiders that attacked the invertebrates have the most similarities with those spider toxins. Now Wolbachia may infect the same invertebrates (arthropods and nematodes). This means that part of this gene has got bacteriophage from an invertebrate animal where DNA exchange has happened.
Researchers have found some proteins similarities in the eukaryotic association domain, and one protein is related to a protein bee protein. Simply put, researchers find that a virus has adjusted its life in two different branches of life, which will help to understand the evolution and the spread of viruses in different branches of life.
How did bacteriophage stolen genes?
Researchers themselves are looking for answers to the same questions. They say some possible ways.
- In one suggestion, genes were transmitted between Wolbachia and eukaryotes, and later Olbacia lost some DNA. When bacteriophage attacks Olbaccia, it inserts its genome portion into the Olbacia genome and during the formation of phage progeny, the phage steals some portion of the bacterial genome.
What is the role of the stolen genes in bacteriophage or what is the benefits of bacteriophage?
Genes stolen by infectious viruses are nothing new. They have some advantages to steal these genes.
For example, they can run off or hide against disease-protection. There are some early life-threatening viruses (such as Mimivirus) that have stolen genes from all branches of life. Bacteriophage usually transfers various poisons or photosynthetic or color genes in bacteria. Bacteria of Cholera Disease thus cause cholera disease by stealing cholera toxin from a bacteriophage (Vibriofaz).