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Current time:0:00Total duration:7:42

Video transcript

so we've talked about how influenza viruses attack cells right but every once in a while it's really really unfortunate but you'll actually get two viruses that affect the same cell so imagine how bad you'd feel in that situation not only did you get sick from one virus you actually picked up two so this can happen in humans it can happen in other animals like pigs as well and it's really kind of just dumb luck when this happens right it's not like it's a coordinated attack this is just by random chance - viruses are going to want to attack simultaneously so in the top one let's say we've got some RNA I'm going to put eight strands of RNA in red and it's going to code this RNA is going to code for little H proteins right this is let's say I'm going to name it H I don't know let's say H 3 H 3 and I'll do one more hemagglutinin protein here and remember it looks like a hand because it holds on to silac acid and you've got some neuraminidase over here right neuraminidase is going to Nick that sound like acid it's going to help the virus exit and let's say this is n2 so we've got H 3 n 2 is the top virus and in the bottom virus I'm going to do let's say five six seven eight I'm going to do a slightly different color this is also an H protein but this is going to be h1 okay so this is h1 and I'm using the color to try to help you identify them as being different and we of course have some neuraminidase on this virus as well and this in your minute ace is green and let's assume that that is n1 so we've got h1n1 on the bottom and we've got h3n2 on the top and these two viruses are ready to go they're ready to attack this cell and this cell of course before these viruses are coming along it's doing its normal kind of routine things it has DNA but once these viruses get in there they basically take over right so the virus RNA gets inside we've got some of that the red RNA there we got some of the blue RNA here and so that RNA starts taking over in command is the cell to make more copies of itself so all of a sudden the cell becomes a factory for the blue virus right the blue RNA virus that's the h1n1 it also becomes a factory for the top virus the h3n2 they just basically both kind of takeover together and so this cell is kind of torn two ways kind of doing a job for the two different viruses and this red RNA is actually coding for things like h3 right this is a protein down here it's making and it's also coding for n2 right so we've got n 2 here more n 2 protein over here and on the other side on the top side you've got some h1 being made right so two different types of hemagglutinin proteins are being made at the same time in this cell and of course you've got two different types of neuraminidase you've got some n1 being made over here as well so this is basically what we see we see the cell making a lot of protein and RNA and eventually this cell is going to start sending out little viruses right and that's what I have on the right side we have the viruses that are exiting the cell and what do they look like I guess that's the question well some of them might actually look exactly like the parents like if it actually gets all the same red RNA or the same blue RNA then it might actually look identical to the parents might even pick up the exact same proteins it might have you know these purple h 3s right might have some purple h 3s might have some n2 over here so actually this one looks basically the same as its parent h3n2 is what we would call this one if we were to name it right and this bottom one the blue one actually would look potentially the same as well this might have some h1 over there may be some h1 on this side and it might also have some n1 right might have some neuraminidase over there and there so if I was to name this bottom one I would actually name it the same thing I would name it h1 and one but the interesting thing is that actually once in a while you get some mix you might get you know some mixing happening maybe you get a couple of blue strands over here maybe three blue strands maybe you get two blue strands over there and when you get mixing of the RNA you might also get some mixing of the protein you might get some protein over here that's actually an h3 and maybe an h3 over here and maybe on the bottom one you'll actually get something different maybe on this one you get an h1 maybe an h1 over here so you get some mixing of the H's and maybe on this side you get an n2 maybe an N 2 and of course that wasn't what the parents look like right and up here maybe you get an n1 so all of a sudden things were looking a little different right and if I was to name these viruses that are coming out these progeny viruses this top one this would be an h3 because it's got a purple looking hemagglutinin and it's a green looking pair of scissors and that was the n1 protein right that would be an h3 n1 and this bottom one over here this would be an h1 because that's the yellow colored hand and the orange pair of scissors we said that was n2 so these are actually quite different so these are different than the parents right and the other ones are the same so when you have different viruses coming out what does that mean well if the virus is successful let's say this one is really successful getting people sick and it transmits from one person to another person really effectively in fact may be the first person gets a few people sick because it's so so contagious maybe a lot of people can get sick from one just one person being sick and of course that's going to spread in all directions right well that's going to cause many many many people to get sick and we would say Wow in this population of people in this community H 3 n1 seems to be the dominant new virus and that process is called genetic shift so this process of a new virus kind of emerging after shuffling up its genes is called genetic shift so that's what people talk about and this of course happens with type A viruses so remember we have type a B and C viruses and this is a process that really affects Type A viruses only now sometimes you might get the other possibility maybe this will come out and it becomes kind of a dud and it doesn't really affect too many people it's not very good at causing disease and if that's the case it would soon be forgotten so this mixing this genetic shifting can happen in people you know you might have a person that's affected by two viruses and that person would then turn around and perhaps affect other people or it can actually happen in animals like you might actually see this happening in pigs so there might be a little pig here that gets sick and this pig then would transmit the disease to maybe the farmer and sometimes you might hear the term mixing a vessel and they're the mixing vessel refers to whether it was a human which was case number one or a pig which was case number two in which the actual mixing of the two type A viruses happened