Conjugation

by Jason Amores Sumpter
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so the last way that pro Kerasiotes can introduce genetic variation is through what's known as conjugation. And this is unlike the other methods. We discussed a direct transfer of genetic material between two physically linked bacterial cells. And this is going to involve that appendage we previously discussed. Called a pill us the plural of that. In case you're curious, Pillai, that's the plural form of pillows. Ah, you know, Latin words. Gonna have strange forms to them. Anyways. A eso This is an appendage used thio connect the two cells that are going to be involved in conjugation. And really, what this all boils down to is the presence of this special plasma called the F plasma. And, um, this plasma actually can become incorporated, uh, into the chromosome, the actual chromosomal DNA of a cell. So really, uh, it's probably better to just call it the F factor, right? That that, uh, term F factor can both mean the f plasma and also theme the all right, you know, f plasma genes having been incorporated into the chromosomal DNA. So essentially, these air just a bunch of genes required for this genetic transfer. So, um, it in order to have conjugation. You need what's called an f positive bacteria f plus. And basically, this is just a bacteria that possesses the F plasmid. Um, you can also have this F prime bacteria. You see that little symbol right there? That's prime. And these are bacteria that have the F factor incorporated into their bacterial chromosome. Right, So you need either F plus or F prime. You also need an F minus bacteria or, uh, a bacteria that is lacking the F factor and is going to act as a recipient of the genes. Right. So, uh, the bacteria that has the F factor is going to pass on the jeans and bacteria that lacks it is going to receive them. So looking at our little model here, basically you have the what's called the donor, and it is going to extend its pillows. And guess what? The genes for that pillows are part of the F plasma. Go figure. Right. Um, so it's going to connect to the recipient cell, and from there the two are gonna be linked. The pillows is actually going to kind of pull them together. Uh, there's gonna be a opening between the cells and the genetic information is going to be transferred. You can see from the donor cell into the recipient cell there. And at that point, that sell that receives the F plasma is going to, um, become a cell that is now capable of acting as a donor and let me hop out of pictures so you could see that. Yeah. So it is now going to be a F plus cell, right? This one was f plus the whole time. This is newly F plus says F plus old f plus Knew what everyone call it old donor. New donor. Right. So now this new donor, now it can make its own pillows right? Because now it has the genes, too. So this is sort of a very simplified version of what goes on during conjugation and again, The main idea is that it involves direct gene transfer from a cell that contains the F factor to a cell that does not contain the F factor. Now, uh, there is a sort of special a case of conjugation that involves what's called in our plasma, and this is just a plasmid. I shouldn't say just but it's It's a plasma that carries a gene that will confer antibiotic resistance. So that's why I say I shouldn't say just these air, actually, super important. Uh, antibiotic resistance is like, you know, probably the most important topic in microbiology right now. Um, because, you know, there are many species that are becoming resistant to most forms, if not all forms of antibiotics that humans have developed. So, um, on our plasma is just plasma that can that carries the gene. That convert confers some type of antibiotic resistance. Uh, it's worth noting that not on Lee can these, um, be transferred via conjugation. But our our plasmids can also be transmitted by transformation and trans duck shin. All right, that's all I have for this video. See you guys next time.