Fungi Reproduction - 1

by Jason Amores Sumpter
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Hi. In this video, we're gonna talk about how fungi reproduce now. Fungi show sexual and a sexual reproduction, though there are some fun guy that Onley reproduce a sexually and we call those duro my seats. Now it's worth noting that all fun guy are going to reproduce using spores regardless of whether it's sexual reproduction, a sexual reproduction, whatever and the sport producing structures that fungi create are usually called fruiting bodies. Kind of an informal name for them. Uh, as you'll see, there are mawr technical terms for types of fruiting bodies on. We'll cover those Aziz we go on now, fungi don't fall into the traditional male female dichotomy. Like many other organisms we've talked about, Do fungi do have mating types, but they're different. Mating types don't actually appear morphological e different. Um, so you're probably wondering how do fund I know who to mate with the answers? They wait and see which bathroom they go in. No, I'm kidding. They use pheromones to communicate their mating type, and these air secreted a chemical signals that the fun guy will secrete and other fun guy will pick up on and say, Hey, you're looking pretty good tonight. Now, uh, if you're curious about learning a little bit more about these chemical signals and fungal mating, Uh, if you check out the chemical signals chapter, you actually can learn a little bit about yeast meeting. Now, before we move on, I do want to say that part of the reason we don't use a simple male female dichotomy when talking about fungi mating types is because they have so many different mating types within a single species. In fact, some species actually will have thousands of different mating types. So that's why the little old male female breakdown just doesn't cut it. Anyhow, fertilization will occur by high fate using together and then eventually, their nuclei fusing together. And this is gonna be something a trend you're going to see in all the types of fun guy we're gonna talk about except the chi trades. They actually do it a little different. We'll get to that later. But first I just want to give you a general overview of what a fungal life cycle might look like, right? This is not a specific. This is just general. So the first stage of sexual reproduction, if you want to think of it in stages is going to be the fusion of haIf A. You see that happening here. We call that plasma gamy, and essentially, it's when the cytoplasm of two cells fuse. But the nuclei don't fuse yet. We don't have fusion of nuclear that actually has its own special name, so the resulting cell is going to be considered hetero carry. Ah, tick. And that's because it's gonna have to, um, it can have two or more technically, But let's just say to for now, nuclei that are genetically different from one another. In the case of our example of fungus, these they're gonna be too happy, Lloyd nuclei that are genetically distinct. It can, uh, it can be more than two nuclei. Just to be clear about that, hetero, periodic can refer to something that has two or more genetically distinct nuclei. And in our example, I'm just gonna leave it at two nuclei. Thio keep things simple, and so you'll often see this written as n plus. And now remember, n usually means Hap Lloyd, but because our fungus is gonna have to half Lloyd nuclei together in a cell we sometimes see it written as n plus n. Now, in our example, we're talking about a cell that is di carry attic meaning it contains two nuclei. Right, So die carry attic means has two nuclei Hetero carry attic. It means it has two or more genetically distinct nuclei. Right? Cario is going thio refer Thio the nucleus and hetero means different die means to That's where these terms come from Now the final stage of sexual reproduction is going to be when those two hap Lloyd nuclei fuse and form a zygote and we call this carry Aga me and you can see that happening right here. Here we have our technically here we're actually seeing plasma gamy and Khoury Aga me. So let me be clear about that. We have first plasma gamy and then here. So this first portion is plasma gamy And then this second portion is Carrie Agony and that is the fusion of the two nuclei in tow. One new now deployed nucleus and this is going to form the zygote. The zygote will form a spore producing structure, right? Fruiting body if you will. And in most fungi, zygote is actually the only deployed stage of the fungus. And that's why we don't really have a good picture of it in this nice little drawing of a fungal life cycle, because it's really often just a transient single celled structure. Now, this fruiting body that you see here you might recognize is a mushroom. Yes, In fact, mushrooms are the fruiting bodies of various fungi. So when we talk about fungi were actually usually talking about the reproductive structures, not the main fungal body, the Mycelium. So, uh, this fruiting body develops, it's gonna give off its spores. Right here we have spores and these spores they're going to disperse. And what this image is trying to depict is being dispersed through rain through insects. Um, that's more the realm of ecology. We'll talk about dispersal, uh, in a different chapter. The main point is, these spores are going thio. Eventually, Germany form haIf A. That's what these are these air haif A. And then the process will repeat to high fe of different mating types. That's what the's two colors. They're supposed to represent mating types. So these two high fate of different mating types will get together again. Fuse haIf a plasma gamy carry agonies. I go leads to spore producing structure, which releases spores, right, the fruiting body. Lisa spores. The spores germinate more haIf a and on and on and on Now, I did say there was an exception to the cycle and that comes in the form of the chi trades, which are actually the only fun guy to exhibit alteration of generations. Remember, alteration of generations is when you have a, um uh, multi cellular spore fight generation and commedia fight generation, right, similar to plants. Ah, and some protests, for that matter. Now what? What distinguishes the chi trades are their flag, elated spores and GAM. It's and we actually have a special term for these flag related spores. We call them Zeus Fours. And these are again produced by hatreds, which are fun guy that do not follow the model of reproduction that we just went through. All right with that, let's flip the page and take a look at some specifics