The insides of the Zika virus

Hi my name is Dr Marta gabrielska and I am working in Australia. In the past I did some work in Scotland and we collaborated with University of Cambridge in England. We wanted to look inside of the Zika virus to check how its genome looks like.

First, let me explain what viruses are. You might not know but there are millions of viral particles in one milliliter of seawater. This is quite a lot. They are really not alive, they become sort of alive when they enter a cell of an animal or a plant. When we have viral infections, we can never use antibiotics to cure them. This is an important thing to remember. Before we go further, let me just explain few words which are important for that topic. Virion is one viral particle, like this one. The envelope is something that some viruses just take from ourselves. It’s additional coating that they can put on themselves to be less visible. Capsid, it is everything that you can see here. These are proteins that protect what is inside the virus. Inside the virus is the most important part of the virus – it is its genome. It contains all the information that virus needs to cause an infection. When I was in Scotland, I was working on flaviviruses. This is a group of viruses which are transmitted by mosquito bites. In this family we can distinguish Dengue virus, Yellow Fever virus, Zika virus, and West Nile virus, and the name flaviviruses comes from the word yellow in Latin – flavus. So, the Yellow Fever virus gave the name to the whole family of viruses. But what viruses have to do with Kinder Surprise eggs? Surprisingly, quite a lot! So, let’s imagine that this Zika virus is our Kinder Surprise egg and what happens when we unwrap the Kinder Surprise egg?

What is left is the capsid of our Kinder Egg viral particle. When we look inside, we open the capsid, we can see there is a packed center of the virus. The Zika virus genome is the RNA molecule. RNA molecule can be in few pieces, it can be one piece, and it can be folded into many different shapes. Just as if you have a Kinder Egg toy inside and you can put it together in many different ways. The Zika virus genome and any virus, has secret instruction how to make the virus and how to fold its genome. But scientists don’t have such instruction, so, how can we see what is inside of the Zika virus? To understand how the Zika virus genome looks like, we need to assemble four pieces, in this case four pieces, of its genome. But how can we do it? How can we put it together? Because there are so many options, we can do it like this, which looks weird, or maybe like this, is it really attached, this is completely separated, that looks pretty likely, but not this one. However, there are so many possibilities and how do scientists can solve this problem? How can we answer this question? So what we did we put a special molecule inside the cells that were infected with the virus. This molecule is called psoralene, but you don’t really need to remember this name. What it does it’s sort of take tiny photos inside the tiny cells and it takes millions and millions of tiny photos. How did it look for us? Well, each tiny photo taken within the Zika virus genome is one of these black dots and we received millions and millions of black dots. These dots give us information how what the Zika virus looks like and we run it through special computer programs. We had to understand, when we put them all together, which of the constructed images are really correct. Is it this one? Yes, it happened maybe this one or this one? And our data when we do analysis gives us the answer to this question. So, in the end, what you can see here, is how we actually see the Zika virus genome. The RNA of the Zika is basically what is inside, and how it encodes the Zika virus. So, for all the possibilities we pick this one as the most common view of the Zika virus genome.
I hope you like this video and that you learned a lot about viruses you learned a few new words maybe. What is a genome? What is RNA? What is the Zika virus? What is a virion and what is a capsid? Just remember, brush your teeth after eating Kinder Eggs, okay? I don’t want to get in trouble with your parents!